Member Login | Contact Us
First Edition, 1967 Second Edition, 1970 Edward A. Steinhaus and Mauro E. Martignoni First,
Second Editions published by USDA, Forest
Service, Pacific Northwest Forest and Range Experiment Station Introduction to the first and
second editions In invertebrate pathology, as in
other branches of science, we are in need of constant attention to and revision
of the meaning of the terms used to describe our findings. Contributions toward
this end are evident in a number of books and papers. However, these
publications do not include lists of many terms which the student, researcher,
or author will find pertinent to his work. Therefore, we have prepared a
glossary of selected terms commonly appearing in the literature of invertebrate
pathology, with the hope that it may be of use to invertebrate pathologists and
to readers of invertebrate pathology literature. We also hope that this will
stimulate the student to analyze a definition or explanation, and that he will
not refrain from challenging the status quo or usage by instructors, textbooks,
and other 'authorities.' Terminology is a convenient tool but
needs constant repair and improvement if it is to serve its purpose in a
satisfactory manner. Thus, the definitions and explanations presented here will
change, new terms will appear, and obsolete terms will be discarded. The glossary presented here has
grown out of a similar list of definitions presented in 1962 when both authors
were on the Berkeley campus of the University of California. At that time, it
was intended primarily for use by students enrolled in courses in insect
pathology at the university. During the intervening years, its usage has extended
far beyond that of the classroom. Moreover, as predicted, those inevitable
changes have occurred in the use and meaning of words which require an
'up-dating' of the previous glossary. Accordingly, we are presenting a revised
list for use by invertebrate pathologists generally, as well as students and
authors of papers concerned with the diseases of invertebrate animals. Most of the glossary to follow consists really not so much of definitions, as of
explanations to indicate the general meaning of words and terms as most
invertebrate pathologists may properly employ them. Derivations,
pronunciations, and variations in meaning may, of course, be found in any
reliable dictionary or lexicon. Moreover it should be remembered that the
explanations in the present glossary are directed particularly to their use in
invertebrate pathology and relate to the situation as found in invertebrates,
especially insects. Many additional terms found in standard reference works
are, of course, also used in invertebrate pathology. With few exceptions (e.g.,
polyhedrosis, granulosis), the names of specific diseases have not been
included in the list. Introduction to third edition We added approximately 400 terms and
doubled the size of the glossary. We improved over 40 definitions from the
Second Edition and deleted less than 30 terms that are no longer used or are
too general for this glossary. Our goal was to emphasize terms that
contemporary scientists would need to know to understand not only modern
publications but also literature published before 1970. For less than 100
terms, we use verbatim (with permission) definitions from three published
sources. One reason to do this is to maintain consistency across disciplines
and across sources within a discipline. Some very important, yet sometimes
vague, terms must be consistently used in a discipline. For
example, Shapiro-Ilan, D. I., J. R.
Fuxa, L. A. Lacey, D. W. Onstad, and H. K. Kaya (2005. J. Invert.
Pathology 88:1-7) presented the history and logic behind the definitions of
virulence and pathogenicity. They addressed one group’s attempt to change the
traditional definitions used in invertebrate pathology. Steinhaus and
Martignoni, in the first two editions, emphasized the variability in the
definitions and use of the word ‘disease’ by presenting the following
statements. There are many definitions of the term disease. A healthy animal
is one so well-adjusted in its internal milieu and to its external environment
that it is capable of carrying on all the functions ultimately necessary for
its maintenance, growth, and multiplication with the least expenditure of
energy. The following are examples of the most significant interpretations of
the word disease: According to Birkeland (1942), “Disease, then is a process, not a thing
and represents the response of the body to injury or insult. ... When the range of easy tolerance within which an organism can
function without too great a strain is passed, the organism may be said to be
diseased or in a pathic state." (Birkeland, J. M. 1942. Microbiology and Man. F. S. Crofts, New
York. According to Engel (1960), "Health and disease are relative
concepts which do not easily lend themselves to simple definition. Disease
corresponds to failures or disturbances in the growth, development, functions,
and adjustments of the organism as a whole or of any of its systems. ... The
broad definition of disease does not confine our attention to any single system
or organization of the body. It permits us to conceptualize disturbances or
failures at all levels of organization--biochemical, cellular, organ,
psychological, interpersonal, or social--and to consider their
inter-relationships. Further, it does not restrict us to any single etiologic
concept but permits the application of a multi-factor concept." (Engel, G.
L. 1960. A unified
concept of health and disease. Perspectives Biol. Med. 3, 459-485.) White (1926) stated "Disease--any destructive process
whatever, no matter how small or of how short duration, comes within the
meaning of the term. Not only are pneumonia and typhoid fever diseases in this
sense, so is broken leg or a cut or bruised finger." White, W. A. 1926. The Meaning of Disease.
Williams and Wilkins, Baltimore. According to Dawkins and Rees (1959), "The chemical reactions
of the cell are not a series of isolated reactions, but are all in dynamic
equilibrium. Interference with one reaction will therefore affect the whole
system to varying degrees. ... Disease can thus be considered as the
modifications in cellular metabolism produced by pathogenic agents." (Dawkins, M. J. R., and K. R. Rees. 1959. A Biochemical Approach to Pathology.
Edward Arnold Ltd., London.) Other Resources We realize that this glossary cannot cover all terms
that an invertebrate pathologist may encounter in his or her work. For example,
invertebrate anatomy and morphology must be understood to study most pathogens.
Yet we have chosen not to place these terms in this glossary. We recommend that
SIP members consult the following sources for definitions of additional terms: Nichols,
S. W. 1989. The
Torre-Bueno Glossary of Entomology. The New York
Entomological Society. New York. Gordh, G., and D. Headrick. 2001. A
Dictionary of Entomology. CABI Publishing. New
York. Kirk, P. M. et al. 2001. Ainsworth & Bisby's Dictionary of the Fungi. 9th Edition. CABI
Publishing. Wallingford, UK Sprague, V. and Becnel, J. J. 1999. Glossary. pp. 531-539. In The Microsporidia and
Microsporidiosis, M. Wittner and L. M. Weiss, eds., American Society for
Microbiology Press, Washington, DC. Lee, J. J., G. F. Leedale, and P. Bradbury. 2000. An
Illustrated Guide to the Protozoa, 2nd Edition. Vol. II pp. 690-1432. Society of
Protozoologists, Lawrence, KS. The Natural History Museum of Los Angeles County has a
good glossary for terms concerning crustacea: http://crustacea.nhm.org/glossary/index.html.
Two Internet glossaries for mollusks are http://www.fish.washington.edu/naturemapping/mollusks/glossary.html
produced by R.L. Body at the University of Washington and http://www.palaeos.com/Invertebrates/Molluscs/Mollusca.Glossary.html
on the Palaeos biodiversity web site. Language We chose to produce this edition in English, not out
of disregard for other languages, but because of the convenience of keeping the
same language used in past editions. Anyone wishing to translate this glossary
into another language is welcome to do so. The Society would likely be willing
to post the translated version on its Internet web site. Permissions to use
copyrighted definitions, however, do not currently pertain to translations. M. E.
Martignoni et al. 1984. Terms used in
invertebrate pathology in five languages: English, French, German, Italian, and
Spanish. USDA Forest Service Pacific Northwest Forest and
Range Experiment Station. Gen. Tech. Rep. PNW 169. Future Revisions Steinhaus and Martignoni stated “this glossary, to
remain useful, must be revised at regular intervals. Users are urged to address
their criticism and suggestions to the compilers and to propose additional
entries to be included in future editions.” Therefore, users are encouraged to
send their new definitions or suggestions for changes to the SIP Publications
Committee for review. Minor changes to the document on the SIP web site will
likely occur on an annual basis without the need for declaring new editions. Acknowledgements The producers of this third edition thank several SIP
members for their assistance. J. Harper provided the electronic, digital files
of the first two editions of the glossary with a note about the wishes of Dr.
Martignoni. L. Solter helped with interactions with the US Forest Service. G.
Blissard provided two important definitions. M. Rotstein added the glossary to
the SIP web site. The Publications Committee granted approval for our work and
the publication of the document on the SIP web site. An
Abridged Glossary of Terms Used in Invertebrate Pathology Third
Edition Citation: D. W. Onstad, J. R. Fuxa, R. A. Humber, J. Oestergaard, D. I. Shapiro-Ilan, V. V. Gouli, R. S. Anderson, T. G. Andreadis, and L. A. Lacey. 2006. An Abridged Glossary of Terms Used in Invertebrate Pathology, 3rd Ed. Society for Invertebrate Pathology. http://www.sipweb.org/glossary Definitions cited with permission from
another glossary or dictionary are indicated with a
number referring to the source at the end of the definition. The sources are
listed at end of glossary. A Abnormality The quality or state of being
abnormal. A deviation
from the normal. A structure,
function or condition different from the usual.
A malformation or teratology. A state of disease. Abundance The incidence or density of organisms in relation to the
area. Acarine disease Parasitism of adult
honey bees by Acarapis woodi (Rennie). The mite infests the tracheae, mainly those
leading from the first pair of thoracic spiracles, and caused them to
blacken. It causes no outward symptoms
but shortens the lives of bees slightly.
Infested colonies can survive indefinitely but sometimes, when most of
their individuals become infested, they die in late winter. See also Isle of Wight disease. Accidental host A host in which
the pathogenic microorganism (or parasite) is not commonly found, nevertheless
one suitable for the pathogen's development. Accumulation (Cumulation) Enrichment of substances, toxins or organisms. Activity
standardization A process by which
the activity of a microbial preparation is measured in standard activity units,
i.e., units accepted by consent as a basis for comparison. Standardization can be of limited import,
e.g., within one laboratory or among few laboratories,
or it can extend nationally and internationally as it does for Bacillus thuringiensis
preparations. See activity unit. Activity titer (Potency) The amount of activity (e.g., insecticidal
activity) per unit weight or volume of a product (such as a virus
preparation). The activity titer is
measured by determining the amount of product needed to obtain a specific
response in a host. See bioassay,
activity unit. Activity unit A precisely
defined standard of measure of the activity of a substance or product (such as
a toxin or a virus preparation).
Multiples of this standard unit are used for
measuring the activity titer (potency) of that substance or product. Activity units are usually defined by national
or international cooperation and accepted by consent as a basis for
comparison. See activity
standardization. Acute paralysis A
fatal disease of adult honey bees and of certain bumblebees, caused by a
virus. Affected bees can neither feed
nor fly, and they walk around with trembling legs and wings. At 30 degrees C. death occurs within
1 or at most 2 days following appearance of the symptoms. The virus particles are isometric and measure
about 28 millimicrons in diameter. Acute Of
short duration. Characterized
by sharpness or severity. As "acute disease." Adaptation Changing of the physiology or morphology of species over many
generations by the process of natural selection Additive effect or additivity Cooperative action between two pathogens or
agents, such that the total effect
is equal to the sum of the effects of the agents taken independently; the
agents may be substituted for each
other in amounts inversely proportional to their activity. Additive See Adjuvant Addled (or abortive
eggs, brood). This term is used by
apiculturists to describe eggs that fail to hatch, larvae that fail to pupate,
and pupae of honey bees that die without any apparent infection. Addled eggs and addled brood are the results
of genetic anomalies. Highly inbred
queens have been shown to produce addled progeny. Adjuvant Aiding
substance to increase the efficacy of a pesticide by the enhancement of
properties like retention and penetration. Affinity Attraction
between organisms or substances. Aflatoxins group
of secondary fungal metabolites (mycotoxins) mostly produced by Aspergillus flavus, A. niger, and A. parasiticus;
toxic and carcinogenic for animals and humans. Age-specific mortality rate A mortality
rate for a specified age group, in which the numerator (number dead) and
denominator (number at risk) refer to the same age group. 3 Agglutinin A
molecule capable of afflutinating particles, probably as a result of its
possession of two or more binding sites specific for determinants on the
particle e.g. some lectins. Aggregation Clotting, agglomeration, agglutination, clotting or
clumping of single parts, cells or individuals. Agonist Chemical
substance, which imitates the effect of signalling molecules, e.g.
neurotransmitter or hormones. Allele DNA code which is located at the same gene locus on homologous chromosomes
responsible for a certain character. Mutation can move the allelic genes to
other loci. Allograft A tissue graft between two genetically
different individuals of the same species. Alternate host See
intermediate host. Alternation of generations The alternation
in the life cycle of an organism of forms produced in a different manner, esp.
the alternation of sexual with asexual generations.1 Amebocyte See Coelomocyte
and Hemocyte. Amensalism A type
of symbiotic relationship in which one of the partners is inhibited and the
other is not affected. American
foulbrood A
disease of larval honey bees caused by Bacillus larvae White. Infection occurs in the youngest larvae and
death is most frequent when the insects are in the prepupal or pupal stage,
after the cells have been capped.
American foulbrood is found at any time of the year when brood is
present, in the temperate and subtropical regions throughout the world. No large beekeeping area is entirely free of
the disease. Synonymous
with Black brood, Ropy brood. Amoeba disease Infection of adult bees by Malpighamoeba
mellificae Prell.
The amoeba multiplies and encysts in the lumen of the malpighian tubules. The infection has not yet been shown to cause
any symptoms. A disease of grasshoppers
in which an amoeba Malameba locustae (King and Taylor), infects
primarily the malpighian tubes has also been called amoeba disease (or amoebic
disease). Amoebic
disease See
Amoeba disease. Amoebiosis Infection caused by an
amoeba. Amplification Raising the number of copies of a gene or plasmid in a cell. Amyloidosis Amyloid
degeneration. A pathologic
condition linked with the formation of deposits of amyloid, a type of protein,
in various organs or tissues.
Amyloidosis occurs in mated queen honey bees, and it seems to cause
premature drone laying. The amyloid is deposited in the cytoplasm of
the spermathecal epithelium of the affected queens. Anamorph (adjective:
anamorphic) The
asexual (conidial or imperfect) stage in the life history of an ascomycete (or,
rarely, basidiomycete) fungus; the anamorph may have a nomenclaturally valid name different from its
teleomorph (sexual state). Anchoring disk A complex
membrane, demonstrated by electron microscopy, appearing as a vertical section
of an umbrella, continuous with the outer covering of the polar filament and
presumed to anchor the everted filament to the microsporidian spore during
discharge of the sporoplasm.1 Anisogamous gametes Gametes or gametic
cells that consistently differ in size, the larger designated “female”, the
smaller “male”.2 Antagonism or antagonistic effect (1) The total effect of two
pathogens or agents on a host is smaller than the effect of the most active
agent alone. (2) Direct impairment of an organism by
another using means of e.g. competition, parasitism, predatory
behaviour. Antagonist Organism which counteracts the development of another
organism. Antibacterial
peptides
Very compact, low molecular weight, often inducible peptides that have
antibacterial activity. Antibiotica Substances, produced by micro-organisms, which inhibit
selectively the growth of other micro-organisms
or kill them. Antibodies Substances (modified
blood globulins in vertebrates) that are produced in the body of the animal in
response to entering or introduced antigens.
Antigen, Nonvirion See Nonvirion
antigen. Antigens Substances
(especially proteins) that are introduced or gain entrance into the blood and
that stimulate the production of antibodies or, as far as insects are
concerned, other protective, lytic, or cidal substances. See also Immunogen. Aphagia Inability to ingest. Apimyiasis Myiasis of the adult honey bee caused by
the larvae of Senotainia tricuspis
Meigen, Rondanioestrus apivorus De
Villers, and certain other fly species. Aplasia The entire failure or organs or
tissues to develop. The
congenital absence of an organ or tissue. Aposymbiotic Separated from its
symbionts. Symbiont-free. Usually refers to mutualistic symbionts (see
mutualism). Apparent infection rate The increase in
disease prevalence per unit of infected host tissue per unit of time (see also
Infection Rate) Appressorium Differentiated apical
structure on a fungal hypha or germ tube closely applied to the host’s outer
surface and serving as an organ from which penetration to the host’s interior
occurs. Archaeocyte An ambocytic cell type found in the
parenchyma of sponges. It acts as a phagocyte
and encapsulative cell and disposes of phagocytized foreign material by
migrating to the exterior of the body of the sponge. Arnhart's
black-egg disease See Melanosis. Asexual reproduction Reproduction by means of
fission or budding, binary or multiple of a single parental organism or by
production of spores.2 Assimilation The energy
requiring formation of autologous organic substances out of internalized
inorganic (in case of most of the plants) or organic (in case of fungi, nearly
all bacteria animals and humans). Asthenobiosis
Comatose condition of insect associated with blockade
of epithelium of Malpighian tubules by means of urates. Appearance is
characteristic for amoebioses. Athrocyte A cell that removes waste substances and
certain foreign material by pinocytosis, storing the material in a granular
form in cytoplasmic vacuoles. Those that
occur in gills of decapod crustaceans also have been termed nephrocytes or
podocytes. Atrophy (1) Decrease in size of a tissue, organ,
or part after full development has been obtained. A wasting of tissues,
organs, or entire body from disuse, old age, injury, or disease. A condition in which
the affected cells undergo degenerative and autolytic changes, become smaller,
and have a lessened functional capacity.
(2) If there is destruction of some of the cells in a tissue we speak of
"quantitative atrophy" (see Hypoplasia (2)). Attenuated infection An infection
which is not immediately followed by overt disease. An attenuated infection may follow a phase of
overt disease. One usually recognized
three types of attenuated infection, i.e., Microbial persistence, Latent
infection, and the Carrier state. See
also inapparent infection or progressive infection. Attenuation The process of decreasing the
virulence of a microorganism. Autograft A tissue graft from one part of the body
to another part of the body of the same individual, or between two genetically
identical different individuals (identical twins). Autoinfection Transmission of infection
from one cell to another in the same host individual in the same or different
tissue. Autoinfective spore One of a class of
spores designated by function. A spore the specific function of which is to inject its sporoplasm
into another host cell of the same or a different tissue. Probably quite
common in the microsporidia.1 Avidity index If, in a
population of phagocytic cells, the particles inside positive cells are
counted, the mean number of paritcles per cell is recorded as the avidity
index. Compare with "Phagocytic
index". Axenic cultivation The rearing of
one or more individuals of a single species in or on a nonliving medium. Axenic Free from associated organisms. Azygospore A
fungal resting spore state of a zygomycete fungus having a thick (bilayered)
wall formed without a prior conjugation of gametangia of a zygomycete fungus.
While azygospores are usually thought to be of asexual origin, this term refers
only to the mode of formation whether or not karyogamy and meiosis occur in them
before germination. Also see zygospore. B Bacillary necrosis Synonym Focal
Necrosis. Multiple
abscesses containing masses of unidentified gram-positive bacteria in the
vesicular connective tissues of the Pacific Oyster (Crassostrea gigas). Has been suspected, but not confirmed, to be
associated with significant oyster epizootics in Japan and the Pacific Coast of
the United States. Bacillary paralysis A disease of
silkworm larvae caused by ingestion of spores and parasporal crystals of Bacillus
thuringiensis var. alesti Toumanoff and Vago and var. sotto
Ishiwata. The sudden onset of general
paralysis, a few hours after ingestion of the toxin, is a pathognomonic symptom
of the disease. The paralysis is usually
irreversible and followed by death. Synonymous with Sotto disease. Bacteremia The presence of bacteria in the
hemolymph or blood of invertebrates and other animals, without production of
harmful toxins or other deleterious effects. Bacterial schlaffsucht Fatal disease of
the Mediterranean flour moth, Anagasta kuehniella (Zeller), and
of other lepidopterous larvae caused by spores and parasporal crystals of Bacillus
thuringiensis Berliner. Bacteriocyte A cell containing mutualistic and
commensalistic microsymbionts distinctly bacterial in nature. See also Mycetocyte. Bacteriophage A bacteria specific virus, often used as vector for gene transfer and in diagnostics
of bacteria. Bacteriosis Any disease caused by the presence
of bacteria. Baculovirus Primarily entomopathogenic, rod-shaped,
double-stranded DNA virus embedded in proteinacious occlusion bodies of viral
origin that are either 0.5-15 micrometer polyhedra or 300-500 nanometer long
granules. Bassianolide A cyclodepsipeptide mycotoxin produced
by mycelia of Beauveria bassiana, Lecanicillium lecanii and other fungal
pathogens of the Clavicipitaceae. Beauvericin A cyclodepsipeptide mycotoxin produced by some
species of Beauveria and Fusarium. Beauverolide A family of cyclic depsipeptide
mycotoxins isolated from species of Beauveria
having suppressive effects against immune responses in some insects. Bee paralysis See Acute paralysis,
Chronic paralysis. Beta-1,3-glucans
Pattern recognition molecule associated with fungi and yeast. Bettlach May disease A paralysis
of adult honey bees, reported chiefly from Switzerland, caused by poisonous
substances in the pollen of Ranunculus species (buttercups). Buttercup pollen is collected by the bees
only when no other forage is available.
The poisoned bees cannot fly, twirl rapidly or turn somersaults, and die
from 3 to 5 days after feeding on the pollen. Binary division Dividing of a cell
into two nearly equal daughter individuals.1 Binding site Special region of an enzyme that binds the specific substrate
(active centre). Bioaccumulation Enrichment of a substance in organisms by uptake from the
surrounding medium or from nutrients. Bioassay Biological assay. The
measurement of the potency of any stimulus, physical, chemical, biological,
physiological, or psychological, by means of the response which it produces in
living matter. Biochemical lesion The initial
biochemical change in tissue cells which precedes any damage visible with the
light microscope. Biocoenosis Community of all living organisms regularly inhabiting a
biotope (life community). Biodiversity Generic term for the entirety and variety of the forms of
life in all levels of organisation Biological control The use, by man,
or living organisms to control (usually meaning to suppress) undesirable animals
and plants. Some authors consider
biological control to be a part of natural control, and use the term to refer
to the action of parasites, predators, or pathogens on a host or prey
population which produces a lower general equilibrium position than would
prevail in the absence of these agents.
Certain nonorganismal biological factors, such as metabolic and genetic
diseases, when used in control may be included in the concept of biological
control. That type of biological control
involving the use of microorganisms in usually called "Microbial
control." Biotic insecticide An organism used
to suppress a local insect pest population.
To some, the word "insecticide" implies a more-or-less
temporary action comparable to that of a chemical insecticide. Others object to the work
"insecticide" as minimizing the difference between chemical and
biological control and as being a source of confusion with purely chemical
products in the minds of growers and others.
In the case of a microorganism, the term "microbial
insecticide" is sometimes preferred. Biotype A strain of a species with distinct physiological
characteristics. Black brood See American
foulbrood. Black Gill disease More correctly
termed Black Gill Syndrome is a generalized sign of host response, in penaeid
shrimp and other decapods, to a variety of infectious and non-infectious
insults to gill tissue. The grossly
observable blackening has been proven in some cases and suspected in others to
result from deposition of melanin by infiltrating hemocytes. Examples of identified causes of the syndrome
are heavy metal toxicity (cadmium) and fungus infections (Fusarium sp.). Black mat syndrome Black mat
disease. An invasive mycotic infection
of tanner crabs, Chionoecetes bairdi Rathbun and C. opilio
Fabricius, Characterized by black hyphae and fruiting bodies, often dense,
encrusting the carapace, and unpigmented hyphae in virtually every organ of the
crab. Epidermis and subepidermal tissues
are replaced by hyphae in advanced cases.
The causative agent is an ascomycete, Trichomaris invadens
Hibbits, Sparks, and Hughes. Black scale
fungus
Myriangium duriaei and similar Myriangium species. Black-egg disease See Melanosis. Blastospores Small,
easily circulated units of vegetative fungal cells formed by budding or
dissociation of mycelium at septa, formed in a host’s hemocoel or in liquid
culture. Note that despite the inclusion of ‘spore’ in this term, these cells
are strictly vegetative and, as such, are physiologically and functionally different
from reproductive spores (conidia, etc.).
Blister disease A disease of
the earthworm Eisenia foetida (Savigny), characterized by the
appearance on the body wall of blisters filled with yellow, cloudy
material. As the disease progresses the
blisters break open and the worm fragments and dies. Blue disease A rickettsial
disease of the larvae of the Japanese beetle, Popillia japonica
Newman, and of other related scarab larvae.
The causative agent is Rickettsiella popilliae (Dutky and
Gooden) Philip. The name of the
rickettsiosis derives from the bluish appearance of the diseased grubs. B-Melanosis See Melanosis. Bonitation Visual
assessment of differences in symptoms, intensity of infestation, phytotoxicity,
effects of plant protectants and others. Brachyosis A bacterial disease of certain Malacosoma
species (tent caterpillars), caused by Clostridium brevifaciens
Bucher and Clostridium malacosomae Bucher. These anaerobic bacteria multiply especially
in the anterior half of the larval midgut, causing a form of dysentery,
sluggishness, shortening of the larval body, and death of the younger
larvae. Older larvae may survive the
disease. Budding Dividing of an individual, uninucleate
or multinucleate, into two individuals of distinctly unequal size.1 Bundle virion See Multicapsid
virion. C Capilliconidium Special type of passively dispersed
secondary conidium of entomophthoralean fungi, which is produced on slender
capillary tube (conidiophore) developing on a primary or secondary conidium. Capsid The protein coat or shell of a virus
particle. The capsid is a "Surface
crystal," built of structure units.
The structure units are the smallest functionally equivalent building
units of the capsid. The structure unit
could be a single polypeptide chain or an aggregate of identical or different
polypeptide chains. In a shell with
cubic symmetry the structure units can associate in a limited number of ways,
forming symmetric clusters. These
clusters are the morphological units which may be seen with the electron
microscope, and for which the word capsomere has been proposed. See also Nucleocapsid and Virion. Capsomere A cluster of structure units arranged on
the surface of the nucleocapsid, in viruses possessing cubic symmetry. These clusters (capsomeres) may be discerned
in electron micrographs of negatively stained preparations. See also Capsid. Capsulate Having a
capsule.1 Capsule (1) A common and very general term that has been applied to a great
variety of unrelated covering devices. (2) A structure composed of hemocytes
that have enclosed a foreign body. Carbon dioxide sensitivity A disease of
adult fruit flies (Drosophila), caused by sigma virus. The presence of sigma virus in a fly is not
harmful so long as the insect is not exposed to pure carbon dioxide. However, even a very brief contact with pure
carbon dioxide gas is lethal to infected (sensitive) flies. The virus is transmitted to the offspring by
the gametes of one or both parents. Carrier state One type of attenuated
infection characterized by the presence of a pathogenic microorganism within or
upon host tissues. There is no evidence
of overt disease in the host, but the pathogen retains its virulence towards
other members of the host's species. Case fatality rate The proportion of individuals
contracting a disease that die of that disease. 3 Castration, parasitic See parasitic
castration. Catabolism Energy releasing metabolic degradation. Caudal appendage Almost any posterior
extension of an organism’s body.2 Cause specific mortality rate The mortality
rate from a specified cause for a population. The numerator is the number of
deaths attributed to a specific cause. The denominator is the at risk
population size at the midpoint of the time period. (Source: Principles of
Epidemiology. Second Edition. U.S. Department of
Health and Human Services, 12/95; IDPH Vital Statistics Report, 1990) cDNA (complementary DNA, copy DNA) A
DNA molecule synthesised by a reverse transcriptase using an mRNA molecule as a
template. The cDNA molecule is complimentary to the mRNA molecule. Cell adhesion factors
An example is
peroxinectin, a hemocyte product of arthropods that mediates cell attachment,
spreading, encapsulation and degranulation; its activities are concomitant with
prophenoloxidase activation. Cell culture This term is used
to denote the growing of cells in vitro, including the culture of single
cells. In cell cultures the cells are no
longer organized into tissues. See also
Tissue culture, Organ culture. Cellular immunity Immunity which is
mediated by cells in the immediate vicinity of the target; usually involves
phagocytic activity and can include extra-cellular processes leading to target
cell death. Censored data Data that result
when the dependent variable represents the time to a terminal event, but the
duration of the study is limited in time.
The major example in invertebrate pathology is the determination of host
survival time after exposure to a pathogen; animals that do not die by the end
of the experiment produce censored data. CFU (colony forming units) Propagation form or cell of a micro-organism, which grows to a
colony on the appropriate substrate. Chalkbrood
fungus
Fungal disease of larval bees, caused by
species of the ascomycete genus Ascosphera. Chalky disease see Chalkbrood
fungus Chalky disease A septicemia of
the cicada Okanagana rimosa caused by a nonsporeforming bacterium
of the family Corynebacteriaceae. Challenge injection An injection of
infective material or of an allergenic substance given to an animal to test for
immunity or sensitization. The challenge
injection is given after a waiting period, following a series of immunizing or
sensitizing injections of the same material. Chemotaxis The migratory response of hemocytes
to chemicals produced by invading microorganisms or necrotic tissue, wherein
the cells are attracted to and acculate at the site of the reaction. Chlamydospore A fungal resistant stage usually
produced by the thickening of the wall on a single cell or small group of
vegetative cells and able to act in a spore-like (dispersive, environmentally
resistant) manner but that immediately continuing vegetative growth upon
‘germination’ rather than producing another type or spore or germ tube. Chromosome cycle Haploidy and diploidy
in the successive phases of the live cycle and the processes of change, if any,
from one number of chromosome sets to another.1 Chronic paralysis A fatal disease
of adult honey bees and of certain bumblebees, caused by a virus. Affected bees are able to feed normally, but
they are feeble and trembly in movement. Their limbs and wings are held
slightly spread. Chronically paralyzed
bees live for several days after appearance of the symptoms,
unlike acutely paralyzed bees (See acute paralysis). Strongly basophilic cytoplasmic inclusions
(Morison's cell inclusions) appear in the hindgut epithelium. The virus particles are ovoid and
occasionally irregularly shaped, with an average size of 27 by 45
millimicrons. They are found in large
numbers in the thoracic and abdominal ganglia of the sick bees. It appears that queens in colonies with
chronic paralysis transmit the virus or susceptibility to the disease or both
to their offspring. Chronic stunt A viral disease
of larvae of the navel orangeworm, Amyelois transitella. Infected larvae grow at a slower rate than
normal larvae and become distinctly pink.
As the disease progresses, the larvae no longer move about and show
signs of fat depletion and desiccation.
The cadavers are dry. The chronic
stunt virus (CSV) is a small isometric RNA virus (diameter 25nm.). Chronic Of long duration. Not acute.
As "chronic disease." Ciliatosis Any disease caused by ciliates (a
class of ciliophoran protozoa). Cistellae Flattened vesicles of uniform size and
clustered around the polar filament
in some microsporidia Thought to be
homologous with the polaroplast of most genera.1 Clear heads,
disease of the See Gattine. Cloning Integration of a gene or a DNA sequence to a vector or into a genome. Coagulocyte A type of hemocyte, more especially a
kind of cystocyte, found in insects.
These cells burst spontaneously on coming in contact with a foreign
surface. Their disintegration leads to
formation of islets of coagulation which involve other hemocytes that are near
the foreign body, but not in contact with it. Codon Information triplet of three neighbouring bases on the DNA or RNA for one amino
acid. Coelomocyte Any cell that occurs normally in the
coelomic fluid of coelomate invertebrates.
Also referred to as leukocytes or amebocytes. Coenocytic Presence of multiple
nuclei in the cytoplasm that is not partitioned by cross-walls, cell membranes,
or complete septa. A nonseptate
condition also known as “syncytial.2 Collenocyte A numerous cell type in sponges that is
occasionally involved in phagocytosis and encapsulation of foreign material. Colony Permanent or
semi-permanent physically very close association of a group of adult
individuals in some specific morphological arrangement with various degrees of
physiological integration.2 Commensal Microbe living in or on another organism
with a relationship the does not benefit or harm the host. Commensalism A symbiotic relationship in which one of
the two partner species benefits, without apparent effects on the other
species. See also Symbiosis. Communicable disease See Contagious
disease. Complement Complement is a system
of enzymes which, upon activation, generates membrane-lytic activity, as well
as molecules involved in chemotaxis and enhanced phagocytosis. The classical
complement pathway is antibody-dependent and therefore not relevant to
invertebrates. However, the alternate complement pathway is activated by
bacteria and yeasts, and has been described in several invertebrates Complicating disease A disease
supervening during the course of an already existing affection. See also Complication. Complication A morbid process or event occurring
during a disease, which is not an essential part of the disease itself, thought
it may result from it or from independent causes. Congenital disease One that is
present in an animal at birth. A
congenital disease is not necessarily inherited. Conidiospore see conidium Note: ‘Conidiospore’ is an inherently redundant
term that it not officially recognized or used by mycologists; its use should
be avoided! Conidium A nonmotile, asexual fungal spore
formed by any of many possible means on some sort of specialized conidiogenous
cell, or formed directly in some instances laterally on a hypha. Contagious disease A disease which
is naturally transmitted by contact, either direct or mediate. Synonymous with
Communicable disease. Contamination Harboring of or contact
with microorganisms (or other organisms such as insect parasites) in absence of
a relationship which may be considered commensalistic, mutualistic, or
parasitic. Control (1, noun) Something that affords a
standard of comparison or means of verification. (2, verb) Control
(biological, chemical, etc.) of insects and other undesirable animals -- the
maintenance of or the effort to maintain a population density below the point
where injury to man's interests occurs. Cordycepin Insecticidal toxin and
antibiotic isolated from fungus Cordyceps
militaris. Coremium (plural: -emia) see Synnema Crayfish plague See Krebspest. Crowding effect
Negative effect of overpopulation on propagation and growth of
the individuals. Cry Abbreviation for the crystal
proteins of Bacillus thuringiensis. Cryptogramm Designation of virus structure as four couple of symbols. Crystalliferous Producing or bearing
crystals. The term is applied to a
number of Bacillus species which, in addition to the endospore, produce a
discrete, characteristic crystal or crystal-like inclusion in the sporulating
cell. One of the best-known
crystalliferous bacteria capable of infecting insects is Bacillus thuringiensis
Berliner. Cumulation See accumulation. Cyclops A deformity of honey bees
("cyclops" bees) of hereditary origin, consisting of a fusion of both
compound eyes at the vertex of the head. Cyst (1) A
nonmotile, thin-walled resting state of fungi and other microbes and protozoa. For pathogenic aquatic fungi,
usually a brief transitional stage formed from a flagellate zoospore or planozygote just before germination to initiate
penetration of a host. For protozoa,
usually a dehydrated, enviromentally resistant and potentially long-lasting
dormant stage in the life cycle. (2) Cyst formation can be a host response. Cytocidal That which kills cells. Cytoplasmic polyhedrosis A viral disease
of insects, mainly the larvae of certain lepidoptera, characterized by the
formation of polyhedral inclusion bodies (polyhedra) in the cytoplasm of the
midgut epithelial cells. See also Polyhedrosis. Cyt proteins
Crystalline Bacillus thuringiensis proteins possessing hemolytic
activity. D Dauer stage or dauer larva
A
developmentally arrested stage in certain nematodes; in entomopathogenic
nematodes it is the only free-living stage and is also known as infective
juvenile. Defaunate To remove from an organism its
commensalistic or mutualistic microfauna, for which the organism ordinarily
serves as a host. Such as removing
flagellates from the alimentary tract of termites. See also Commensalism, Mutualism. Deficiency disease A disease resulting from lack of
carbohydrates, proteins, amino acids, fatty acids, vitamins, or trace minerals,
or other essential constituents and elements of the diet. Definitive host Primary host. When a parasite lives in two or more hosts,
this is the host in which the parasitic organism reaches the adult stage and
undergoes sexual reproduction. Density, population See Population
density. Density-dependent factors Factors whose effects on a population are
dependent upon thedensity of that particular population. Density dependence may
be direct or inverse. Density-independent factors Factors whose effects
on a population are not dependent upon the density of that particular
population. Densonucleosis A fatal disease of larvae of the wax
moth, Galleria mellonella (Linnaeus), caused by a virus. The agent replicates in most tissues of the
insect, with the exception of the midgut and nervous system. The nuclei of the infected cells become
progressively larger, lose their characteristic structure and, in histological
preparations, they appear as compact, densely stained masses. The virus particles are isometric, with an
average diameter of 20 millimicrons. Dermo (Perkinsiosis). A parasitic disease of the
American oyster (Crassostrea virginica)
caused by the protistan parasite Perkinsus
marinus (formerly Dermocystidium
marinum). Dermomyositis A disease occurring in several genera of
parasitic nematodes. It is characterized
by necrotic cuticular lesions. The
intestinal bacteria of the host mammals have been implicated as causal agents. Destruxins A group of cyclic depsipeptide
mycotoxins produced by some Metarhizium
isolates and by other fungi and that have some varying insecticidal effects. Deuteromycetes, Deuteromycotina, Deuteromycota Class, Subkingdom,
and Kingdom, respectively, of “imperfect” fungi not routinely found to produce
a sexual state but forming conidia or only sterile mycelium. Two
classes—Hyphomycetes (including almost all entomopathogenic forms occur) and
Coelomycetes (with the conidial apparatus enclosed in a walled fruiting
body)—are reocognized (neither class with orders or families recognized) but
mycologists are using phylogenetic techniques to remove fungi from this group to
classify them appropriately with their phylogenetic relatives in the
ascomycetes and, to a lesser extent, basidiomycetes. Deutomerite Nucleus containing,
posterior most segment of a septate gregarine.2 Diagnosis To distinguish one disease from
another. The
determination of a disease from its signs, symptoms, etiology, pathogenesis,
physiopathology, morphopathology, etc. Diapedesis (a leaping
through). In human and veterinary
pathology, the use of the term is confined to the passage of blood cells, especially
erythrocytes, through unruptured vessel walls into tissues. In invertebrate, especially molluscan,
pathology the term is also used for the passage of leucocytes which may or may
not contain phagocytosed material across epithelial borders to the exterior of
the body. Diathesis An inherited constitutional state
whereby an individual is especially liable to a certain disease. Digenic life cycle A life cycle that involves two
different host species.2 Dihaplophase That part of a
microsporidian life cycle in which each individual is diplokaryotic.1 Dihaplophasic Diplokaryotic.1 Dimorphosporous
Having in the life cycle two distinctly
different morphological types of spores.
May be used as a replacement for the ambiguous term “dimorphic”.1 Diplokaryon A pair of haploid nuclei, more or
less intimately associated and functioning together as a diploid nucleus.1 Diplokaryotic Having one or more
diplokarya. Dihaplophasic.
1 Diplophase That part of a
life cycle in which the nuclei are diploid.
Limited to the zygote in microsporidia.1 Diplosis Doubling of the
chromosome number.1 Direct causes Those factors or
agents which cause disease directly, including poisons, microorganisms,
entomophagous parasites, physical or mechanical agents, glandular disturbances
and nutritional deficiencies. At times a
single agent may be both a predisposing and a direct agent--cold may predispose
to bacterial infection and also be the direct cause of tissue death by freezing. Also called "Primary
etiologic factors." Disease Lack of ease. Departure
from the state of health or normality. Condition or
process that represents the response of an animal's body to injury or insult. A disturbance of function or structure of a tissue or organ of the body,
or of the body in general. (See also Syndrome) Disinfect To eliminate pathogenic organisms or render them inert. Disintegration,
watery See Watery
disintegration. Disporoblastic Pertaining to a sporont
that produces two sporoblasts.1 Disposition The genetically determinated susceptibility of a species to a damage factor. Dissimilation The energy generating degradation process of the
metabolism. Distal Situated away from the
point of attachment or origin.
Recommended for use in reference to organelles associated with the
coiled polar filament, in microsporidia as the distal (rather than “posterior”)
part of the polaroplst.1 DNA (deoxyribonucleic
acid). Polymer compound of deoxyribonucleotides. The
nucleotides consist of an organic base (adenine, thymine, guanine or cytosine),
a sugar molecule (desoxyribose) and a phosphoric acid. The genetic information
is encoded by the sequence of the different bases. Drone broodiness See Morbid
drone-laying. Drone-laying See Morbid
drone-laying. Droopy wing syndrome A disease of
adults of the Mediterranean fruit fly, Ceratitis capitata. The disease, of unknown etiology, is
characterized by the insect's inability to fly and by the abnormal resting
position of the wings. Various flight
muscles of droopy-winged individuals are missing or underdeveloped. Dustable powder Special powder formulation of microorganisms used in
biological control. Dutch shell disease Similar to or the
same as Maladie du pied. Dysentery A term given to a number of disorders
marked by lesions of the alimentary canal and often attended by abnormal
frequency and liquidity of fecal discharges.
In sericultural practice the term flacherie has been used for certain
forms of dysentery of the silkworm larvae. E Eclipse period In the developmental
cycle of viruses, a phase or period, occurring immediately after infection
(i.e., immediately after a virus enters the host cell), in which infective
particles cannot be detected. The phase during which the infected host cell contains no material
capable of infecting another call or another host. ED50 See Median effective dose. Effectiveness Efficacy.
A product's ability to produce the specified action,
e.g., the ability of a microbial preparation to actually control the intended
target pest. EIA (Enzyme
immuno assay). Quantitative
determination of biologically active substances (e.g. Hormones, Pharmaka,
Viruses, Antibodies) in liquids containing antigens
labelled with enzymes. ELISA (Enzyme linked immuno sorbent
assay). A technique to detect or quantify specific serum antibodies based on
tagging the antigene-antibody complex. Encapsulation The process of forming a capsule of
hemocytes around material recognized as non-self; an immune response to
material too large to be phagocytosed by individual hemocytes. Encystment The
formation, by a parasite, of a covering or a protective wall around itself. Among fungi,
only flagellate, wall-less cells such as zoospores are referred to as
undergoing encystment. Endogenous virus Virus in which the
principal mode of transmission is from parent to progeny. An endogenous virus is postulated to be
produced by a gene which may be part of the genetic complement of each member
of a species. The potential for virus
production would always be present in each member of the species, but virus
proliferation would be suppressed by cellular controls, in healthy
individuals. Compare with Exogenous
virus. Endospore The chitinous
inner spore coat of the microsporidian spore.1 Endotoxins Substances produced by
microorganisms which are not secreted into the surrounding medium but are
confined within the microbial cell. They
are released after autolysis. Enterolith An intestinal calculus. A concretion formed in the intestinal tract. Enterolithiasis
The presence of calculi
(enteroliths) in the intestinal tract of an animal. Rectal enteroliths occur as single or
agglomerated spherical or polymorphous concretions in adult queen honey bees. Entomogenous Adjective describing a
microbe developing on or in insects without specifically indicating whether the
relationship is commensal, parasitic, or pathogenic. Entomoparasitic Parasitic to insects; a relationship between
an insect and an organism in which the organism benefits at the host insect's
expense; host mortality is not necessarily a requirement for the parasite's
development. Entomopathogen A microbe
affecting insects (or in a more general sense, other terrestrial arthropods
including arachnids), usually causing mortality in the host (as opposed to a
more benign relationship). Entomopathogenic nematode In insect
nematology, the term is specifically used to refer to parasitic nematodes that are mutualistically associated with
bacterial symbionts; all life-stages of the nematode, except for the dauer stage,
are found inside the insect host; examples are Steinernematidae and
Heterorhabditidae. Entomopathogenic Refers to microorganisms and viruses
capable of causing disease in an insect host. Entomophagous Insectivorous. Refers to the consumption
of insects or their parts. Entomophilic Used to cover the associations
between insects and plant microorganisms, insects and protozoa, and insects and
nematodes. "insect-loving." Entomophyte or
Entophyte A plant living
within or on the body of an insect. Entomophytic Refers to almost any relationship
between plant microorganisms (bacteria and fungi) and insects. Do not use when referring to protozoa. Enzootic disease A disease
(usually in low prevalence) which is constantly present in a population. Epimorphic regeneration
(epimorphosis) Replacement mediated by undifferentiated cells at the site of
the injury or lost body part.
Undifferentiated cells may originate by the dedifferentiation of
previously existing specialized cells or from a reserve of pluripotent cells
from embryonic stages. Episome An element which carries genetic
material, is able to transmit inheritable traits and to alternate between
autonomous and integrated states in the host cell. In the integrated state an episome is
physically associated with a chromosome, where as in the alternative,
autonomous state it is extrachromosomal.
The infecting genome of certain viruses may integrate with the host
chromosome, and thus such viral genes are also episomal genes (e.g., the
temperate bacteriophages in the lysogenic cycle have an integrated genome,
which is termed prophage, in the host chromosome). Epitope Region of a macro-molecule which is detected by antibodies. Epizootic wave A disease phenomenon in animal populations
characterized by important attributes, as the number of individual organisms
afflicted by a given disease in a certain area, and the manner in which this
number increases and decreases in a given period of time. Epizootic An outbreak of disease in which
there is an unusually large number of cases.
A disease or a phase of a disease of high morbidity and one that is only
irregularly present in recognizable form.
See also Panzootic. Epizootiology The field concerned with the study
of diseases of animals on the basis of mass phenomena. Concerned with diseases as
they occur in groups of animals (including invertebrates) rather than in the
individual animal. Eradication The removal of all recognizable
units of the infecting agent from the host.
Consequently, the reappearance of the infecting agent in the host should
be traceable to exogenous reinfection. Also, the complete removal, destruction, or extirpation of a living
organism from its environment. ET50 See Median effective time. Etiology The study of the causes of disease. European foulbrood A disease of
larval honey bees caused by Streptococcus pluton (White). Mortality is high among 4- or 5-day-old
larvae in typical epizootic outbreaks of the disease, but occasionally, sealed
brood may die, too. Fairly common
secondary invaders of the diseased larvae are Streptococcus faecalis
Andrewes and Horder and Bacillus alvei Cheshire and Cheyne, both
of which are responsible for the foul odors emanating from the dead
larvae. The disease is usually enzootic
throughout the beekeeping areas of the world, with well-defined seasonal
epizootics at the beginning of nectar flows.
Synonymous with New York bee disease, Melting brood. Euryxenous Having a broad host
range.2 Exogenous cycle Part of the life cycle of a parasitic
organism taking place outside the host.2 Exogenous virus Virus
transmitted between members of a species by contagion. Compare with Endogenous virus. Exospore The proteinaceous
outer spore coat of the microsporidian spore.1 Explant An excised fragment of a tissue or
an organ used to initiate an in vitro culture. Explosive corpuscles Hemocytes in
crustaceans that burst, releasing cell contents that lead to clotting of the
plasma. See Fibrin-ferment. Extotoxins (also called
"Ectotoxins," "True toxins," and "Soluble toxins") Poisonous
substances produced by the microbial cell and liberated into the surrounding
environment, without destruction of the cell. Extrusion apparatus In
microsporidia, vehicle for injecting a sporoplasm into a host cell. It is composed of polar sac, polar aperture,
polaroplast, polar tube and posterior vacuole.1 F Fecund Capable of producing many
offspring. Fecund emphasizes abundance
or rapidity in bearing offspring.
(Fecundity is the power of a species to multiply rapidly.) Compare with Fertile. Fertile Capable of producing living
offspring. Also said
of females capable of becoming fertilized. Compare with Fecund. Fibrin-ferment A substance
found within the crustacean hemocytes called explosive corpuscles that acts on
a fibrinogenlike substance in the plasma, causing it to coagulate. Fission Cell division.2 Fixed macrophage A stationary
phagocytic cell, especially in the arthropods.
When occurring in groups these cells are called phagosytic organs or
lymphoid organs. Flacherie, touffe See Touffe
flacherie. Flacherie, Viral See Viral
flacherie. Flacherie A term used to describe the flaccid
condition (flaccidity) seen in silkworm larvae suffering from dysentery. The affected larvae appear flabby, weak,
withered, or loose-hanging. Death is
rapidly followed by a darkening of the body and decomposition of the larval
tissues. Many of the early pathologists
used the word flacherie indiscriminately for various maladies of differing
etiology, in different species of insects, implying "a diseased condition
accompanied by diarrhea." In modern
usage the term should be accompanied by a modifier, to denote one type of
flacherie as distinct from another of differing etiology as, e.g., Viral flacherie, Touffe flacherie. Flagellosis Infection with a
flagellate protozoan. Focal necrosis A type of
bacterial disease in oysters from Japan and areas of Washington State. Infections occur as pockets of
bacteria-filled abscesses and are thought to cause mortality in affected
oysters. Foot disease
in oysters See Maladie
dupied. Foulbrood See American foulbrood, European
foulbrood. FP variant Few polyhedra
variant. A plaque
variant of certain nucleopolyhedrosis viruses which forms few or no polyhedra
in the nuclei of susceptible cells in vitro. Compare with MP variant. G Gaffkemia, Gaffkaemia A highly fatal
disease of the American lobster, Homarus americanus
Milne-Edwards, held in artificial ponds.
The causative organism, Aerococcus viridans var. Homari
(Hitchner and Sniezko), is a gram-positive micrococcus and is found in the
hemolymph and hemocytes of the lobsters.
The diseases has been produced experimentally
in certain crabs. Gametangium Among fungi, an organ functioning as a
sexual organ that either fuses with another gametangium or in which the
cytoplasm cleaves (as a special class of sporangium) to produce gametes that
are released into the environment. Gametangial nuclei are either initially
haploid or are diploid and undergo meiosis. Gamete A differentiated sex cell or sex nucleus
capable of fusing with another compatible cell or nucleus in sexual
reproduction. Gametocyst Cyst formed by the
union of two gregarine gamonts, with secretion of a wall around them.2 Gametogony Production of gametes in
the final stages of the haplophase.
Preferable to “gametogenesis” which usually implies gamete production
accompanied by meiosis.1 Gametophyte Haploid
generation in the life cycle of a fungus with alternating haploid and diploid
generations; gametes are produced by this stage. Gamont The cell or stage
in the life cycle that will produce one or more gamonts.2 Gas-bubble disease A condition in
which the blood is filled with bubbles of gas.
Caused by exposure to water supersaturated with air or other gases. It
is known to occur in aquatic arthropods and mollusks. Gattine A term used to describe a type of
Flacherie of silkworm larvae, said to be caused by a virus and a concomitant
infection by enterococci closely related to Streptococcus faecal
Andrewes and Horder. However, the viral
origin of gattine remains in doubt.
Certain climatic and nutritional conditions are also known to act as
predisposing factors necessary for the proliferation of the enterococci and
production of overt disease. The cephalic
end of the affected silkworms frequently becomes swollen and almost
translucent--thus gattine is also known as disease of the clear heads. Gene bank Public data base for DNA and RNA sequences. Gene expression Synthesis of the functioning product of a gene. Gene DNA segment, which encodes one
protein. Genome The genetic material of an
organism. More specifically, a set of
chromosomes with the genes they contain. The haploid karyotype. Genomics
Molecular research of the genome. Genotype All the
genes of one organism in its entirety. Germination ability Capacity or ability of seeds or spores to germinate. GMO
(Genetically modified organism) Organism with artificial modified genetic
material, which doesn’t occur naturally in that species. Gnotobiotics Field of biology concerned with
breeding or culturing of organisms by themselves or in association with other
completely known kinds of organisms. (Adj. gnotobiotic). Gradation The time interval between one lowest
point of the density of an animal population and the next, thus including one
full wave of the numerical fluctuation of the population. Granulin The protein of the crystalline body
(capsule) surrounding the granulosis virus rod.
Synonymous with, but preferred to, "capsule protein, " "matrix protein," "inclusion-body
protein," and "proteinic crystal." Granulocyte A type of leucocyte or hemocyte that is
distinguished cytochemically by the presence of basophilic and/or acidophilic
cytoplasmic granules. Compared to
hyalinocytes, these cells are larger and have smaller nucleocytoplasmic ratios.
See also leucocyte. Granulosis A virus disease of certain insects
characterized by the presence of minute granular inclusions (capsules) in
infected cells. (One speaks of a
"granulosis virus" but the inclusion body itself is referred to as a
"capsule.") Graphytosis
A disease of May beetle, Melolontha
melolontha, caused by bacterium Bacillus
tracheitis. Grasserie Nucleopolyhedrosis of the
silkworm, Bombyx mori (Linnaeus).
See also Jaundice. Gray crab disease A disease of
the blue crab, Callinectes sapidus Rathbun, characterized by
progressive weakness leading to death.
Sick and dead crabs are often grayish in appearance. The disease occurs in crabs held in shedding
tanks. It is caused by a protozoan, Paramoeba
perniciosa, which is found in large numbers in the body fluids and
tissues. Synonymous
with "Paramoeba disease", and "Paramoebiasis". Green muscardine fungus Fungi, usually species of Metarhizium or Nomuraea, producing a mycosis of various insects whose mycotized
bodies are covered by a mass of green spores. Gregarinosis A disease caused by a gregarine. Gross pathology The study of
macroscopic structural lesions. Abnormalities of gross structure. Distinguished from histopathology. H Hairless-black syndrome A syndrome
characteristic of a disease of adult honey bees. Sick adult bees tremble, become paralyzed,
and frequently withdraw from the main cluster to remote parts of the hive,
where they die. Some sick bees are
attacked by their hive mates and become denuded of hair and shiny black. In rare instances these bees are eventually
stung to death. Histological lesions
occur in the intestinal epithelium and in thoracic and abdominal nerve
ganglia. Morison's cell inclusions have
been observed in the hindgut epithelium of sick bees. A virus similar to the agent of chronic bee
paralysis has been isolated from bees suffering from hairless-black syndrome. Haplophase That part of the
life cycle in which all of the nuclei are
haploid. Haploid phase.1 Haplophasic Having only unpaired
(haploid) nuclei.1 Haplosis Reduction of the
chromosome number from diploid to haploid.1 Healthy A healthy animal is one so well-adjusted
to its internal milieu and to its external environment that it is capable of
carrying on all the functions ultimately necessary for its maintenance, growth,
and multiplication with the least expenditure of energy. Heidenreich's disease Also called
Histolytic disease. A lethal disease of
larvae of rhinoceros beetles (Oryctes). The etiology of Heidenreich's
disease is unknown, but many of its symptoms and signs are very similar to
those of a viral disease (Watery disintegration or Wassersucht) of cockchafer
grubs (Melolontha). The diseased
larva fails to accumulate lipids, and its body becomes translucent, especially
in the abdomen. The fat body and muscles
become atrophic and eventually necrotic.
Necrosis can be observed also in the integument. As disease progresses, the larva ceases to
move. Hemagglutinin A molecule (e.g. an antibody) which
agglutinates vertebrate erythrocytes by combining with surface membrane-bound
receptors (determinants). Hemocoel The main body cavity of an invertebrate with
an open circulatory system, such that the fluid, pumped by the heart, leaves
open-ended arteries and percolates between major organs in the body cavity
before returning to the heart. Hemocyte A colorless blood cell. See Leucocyte for a complete description. Hemocytic infiltration The migration of
hemocytes into tissues containing foci of infection, injury or necrosis. Hemolymph The body fluid of an invertebrate
with a hemocoel. Heritability The
heritability is the proportion of the phenotypic variation in a population that
is due to the genetic variation. Variation among individuals may be due to
genetic and/or environmental factors. Heritability H2 equals variance of the genotype divided by variance
of the phenotype. Heteroecism The necessity of two host species
for the completion of the life cycle of certain fungi (e.g., Coelomomyces species, in which the
diploid and haploid states affect mosquitoes and copepods, respectively). Heterogenic. Used to
describe parasitic protozoa whose life cycles manifest an alteration of sexual
and asexual generations.2 Heterokaryon (Heterocaryon)
– Somatic cell hybrid containing two (or more) genetically distinct nuclei,
usually forming after hyphal anastomoses (fusions) among compatible but
genetically different strains of the same species. Heterokaryotic Possessing more than one
kind of nucleus (e.g. micro- and macronuclei).2 Heterosporous Having more than one
kind of spore. Often used to replace the
ambiguous terms “dimorphic”, “trimorphic”, or “polymorphic”.1 Heterothallic Fungal species whose sexual
reproduction requires matings between two individuals having different but
compatible mating types. Hexamitiasic infection Caused by species of
Hexamita. Although well-known as pathogens of wild fowl, certain Hexamita
have been indicted as the cause of mortalities in several species of
oysters. Some authors consider Hexamita
to be only fortuitous secondary invaders in dead or dying oyster. See also Pit disease. Histochemistry The microscopic study of the
chemical characteristics of tissues, through the use of substances (dyes, etc.)
producing identifying chemical reactions. Histolytic disease See Heidenreich's
disease. Histopathology A study of abnormal microscopic changes
in the tissue structure of an invertebrate animal (or other organism). H-melanosis See Melanosis. Holidic Pertaining to a medium
(used for growing organisms) whose intended constituents, other than purified
inert materials, have exactly known chemical structure before the medium is
compounded. See also Meridic, Oligidic. Holomorph Among the
pleomorphic fungi (ascomycetes and their conidial states), the term referring
to the entire life history of the fungus representing both teleomorph and any
and all anamorphs. Homeosis Heteromorphosis. Heteromorphous
regeneration. During
regeneration, the replacement of an organ or appendage by one belonging to
another region of the body. See
also Teratology. Homeotic mutation A mutation that
causes the formation of an organ or appendage in a segment in which it does not
usually appear. Homokaryotic Possessing only one kind
of nucleus.2 Homothallic Fungal species whose sexual
reproduction can be accomplished by a single genotype without requirement of
mating with a second individual with a different but compatible mating types. Horizontal transmission The transmission
of an infectious agent through space, from one individual host to another,
except direct transmission from parent to offspring (see Vertical
transmission). Horizontal transmission
may be accomplished by means of vectors or by means of the dissemination of
infectious particles by physical agents, such as wind and rain. Compare with Vertical transmission. Host An invertebrate that harbors or
nourishes another organism. See Accidental host, Alternate host, Definitive
host, Intermediate host, Natural host, Normal host, Host of choice, Primary
host, Secondary host, Substitute host, Transport host, Typical
host. Host of choice A host that is
biologically, technically, and economically preferable for large-scale propagation
of a pathogenic microorganism. The host
of choice can be the natural host or a substitute host. Humoral immunity Immunity which is
mediated by substances in solution in the blood or hemolymph. While being ultimately of cellular origin,
such substances are either released well before encounter with their target or
are released by cells located in a position spatially separate from their
target. Hyaline Glassy, clear,
transparent.2 Hyalinocyte A type of leucocyte or hemocyte that is
characterized by the absence of cytoplasmic granules. Compared to granulocytes, these cells are
smaller and have larger nucleocytoplasmic ratios. See also leucocyte. Hybridoma cell Cell, which is a product of a cell fusion of special cancer cells (myeloma
cells) and antibody producing cells (B-lymphocytes). Hybridoma cells are used
to produce monoclonal antibodies. Hyperaminoacidemia Presence of amino acids in the blood or
hemolymph in excess of the normal amount.
E.g., silk retention in silkworms produces a lethal increase of amino
acids in the hemolymph of the insects.
See Silk toxicity. Hyperplasia An increase in the number of
functional units of an organ (organelles, cells, tissues), excluding tumor
formation, whereby the bulk of the organ is increased in response to increased
functional demands. See also
Hypertrophy. Hypertrophy An increase in size (weight) and
functional capacity or an organ or tissue, without an increase in the number of
structural units upon which their functions depend. Hypertrophy is usually stimulated by
increased functional demands. See also
Hyperplasia. Hyphomycetes, hyphomycete, hyphomycetous Class (followed by
two adjectival forms) of conidial fungi including many entomopathogenic species
that are primarily anamorphs (conidial stages) of ascomycete fungi in the
Clavicipitaceae (Sordariomycetes: Hypocreales). Hypoplasia (1) A defective or incomplete
development of an organ system, organ, or tissue. A hypoplastic organ or tissue is one that
never reaches normal size. (2) Sometimes
used to indicate an atrophy caused by the destruction of some of the elements
(e.g., cells) rather than a general reduction in size (= "Quantitative
atrophy"). I ICP (Insecticidal crystal protein)
Proteins included in a crystal inclusion body of the bacterium Bacillus thuringiensis that is toxic to
insects Immunity Species-determined inherent resistance
to a disease agent. Immunization The process of increasing the
resistance of the host. Immunogen It appears that an immune response
in an invertebrate is not the consequence of an antigen-antibody-globulin
reaction but more likely the result of the production of some other principle
in the host. Thus the term
"immunogen" may be used to replace "antigen" when
describing the stimulus to immune response by an invertebrate. Imperfect fungi A fungal state
without any apparent sexual reproductive apparatus but that reproduces by means
of asexual spores or as a sterile mycelium.
(see Deuteromycetes and Hyphomycetes) In vitro In the "test tube," or
other artificial environment. Outside a living organism. In vivo In the living
organism. Inanition Exhaustion from lack of
nutrients. The
physical condition resulting from the complete lack of nutrients. Inapparent infection An infection which
gives no overt sign of its presence. (In
human medicine the word "subclinical" may be used as an
alternative.) See also "Attenuated infection." Inborn disease See Inherited
disease. Incidence (of a disease)
The number of new cases of a particular disease within a given
period of time, in a population being studied.
For example, in a population of 1,000 lepidopteran larvae there may be
20 new cases of cytoplasmic polyhedrosis discovered on a certain day. These 20 cases represent the incidence of
cytoplasmic polyhedrosis for that day.
The incidence rate is 2 percent. Compare with Prevalence (of a disease). Incitant A factor that incites or activates
occult pathogens. Inclusion body A localized
intracellular lesion specifically associated with viral infection. Incubation period The period of
time elapsing between entrance or introduction of microorganisms in the animal
body and the development of symptoms and signs of an infectious disease. Independence or independent effect The total effect
of two pathogens or agents on a host is equal to the effect of the most active
agent alone. Induction The activation of an occult
pathogen, leading to progressive infection and disease. In particular, the provoked
transformation of a provirus into a virulent (cytocidal) virus. Infaunate To introduce a commensal or
mutualistic microfauna into an organism that is capable of serving as a
host. The introduction of certain
flagellates or ciliates in a defaunated termite constitutes an infaunation. Infect Individual cells or
groups of microbial cells complete entry to a host, overcome the host’s
defensive reactions, and then initiate a disease of the affected host. Infection rate The increase in
disease prevalence per unit of inoculum per unit of time; this term is often
used mistakenly in place of “prevalence.” Infection, Attenuated See Attenuated
infection. Infection, mixed See Mixed
infection. Infection, progressive See Progressive
infection. Infection, Secondary See Secondary
infection. Infection The
introduction or entry of a pathogenic microorganism into a susceptible host,
resulting in the presence of the microorganism within the body of the host,
whether or not this causes detectable pathologic effects (or overt disease). In the case of the viruses, an infection has
been defined as the introduction into a cell or an organism of an entity able
to multiply, able to produce disease, and able to reproduce organized infective
entities. See also Attenuated infection, Progressive infection, Secondary
infection, Autoinfection, Reinfection, Superinfection, Mixed infection. Infectious disease Disease caused by the
actions of a living organism. Infective phase The last phase of
the developmental cycle or a virus, in which the virus acquires
infectivity. The end result of the
assembling of the genome and proteins of a virus during the maturation phase. Infective unit Among
pathogenic eukaryotes, the particular spore or other cell type that, after
contact with or ingestion by a susceptible host, is able to cause infection and
disease. Infectivity The quality of being infective. The ability to produce
infection. Infestation The living in or on a host by
metazoan parasites, such as an infestation of flies by mites. Some authors limit "infest" and
"infestation" to external organisms, in most cases visible to the
naked eye. Inflammation When cells are injured or destroyed
in many invertebrates an immediate protective response, termed inflammation,
occurs at the site of injury. The inflammatory
response destroys, dilutes or isolates the injurious agent and damaged or dead
cells. Phagocytosis, diapedesis and
encapsulation are important parts of the response. The pattern of response, when it occurs, is
basically similar, regardless of the nature of the injurious agent, the site of
the injury, or the taxonomic position of the injured organism. The successful conclusion of the inflammatory
response is usually arrived at by one of three processes. (1) Resolution (a return of the tissues to normal,
when no loss of tissue occurred), (2) Regeneration (a return to normal, in
which lost tissue is replaced), or (3) Repair (when there has been considerable
tissue damage, the lost tissue does not regenerate but is replaced by scar like
tissue). Although most medical dictionaries and human pathology textbooks
define inflammation as the local reaction of tissues to injury, some
invertebrate pathologists object to the use of the term in reference to
invertebrates because not all the cardinal signs of inflammation (redness,
swelling, heat, pain and loss of function) occur in the reaction to injury in
invertebrates. While the cardinal signs
are included in most definitions, they are descriptive of the process in mammals
and birds rather than essential parts of the definition. Inherited disease A disease which
arises from the germ plasm of the parent.
Abnormal characters or qualities determined by inheritance and
transmitted from parent to offspring. Synonymous with Inborn disease. Injection The act of introducing a fluid into
a vessel, cavity, or tissue of an organism, through a puncture in the
integument, by means of a suitable instrument (e.g., microinjector). Compare with inoculation. Inoculation The act of introducing a
microorganism (in particular, a pathogenic microorganism) or virus into (or
placing it onto) an organism or substrate.
When working with organisms, this term covers all routes of
administration, including injection and microfeeding. Inoculum The
microorganisms used in inoculation. Inquiline An organism that lives habitually
on or within the body of another, or in its nest or abode, without benefit or
damage to either. See Inquilinism. Inquilinism A type of symbiotic relationship in
which one of the two partners (Inquiline) lives habitually on or within the
body of the other partner, or in its nest or abode. This relationship is not obligate, and either
of the two partners benefits or suffers harm. Insert (DNA) Exogenous DNA
integrated into a cloning vector. Integrated virus See Episome. Interface A surface regarded as the common
boundary of two bodies or spaces. In
microsporidia the boundary is in some cases the outer surface of the parasite
plasmalemma and in other cases an envelope external to that plasmalemma.1 Interfacial envelope An envelope of
any composition or origin that is situated between the plasmalemma of the
parasite and the hyaloplasm of the host cell.1 Intermediate host Secondary host. Alternate host. When a parasite lives in two or more host species,
this is the host species in which immature intermediate,
or asexual stages of the parasite occur. Intoxication Poisoning. Includes poisoning by
toxins. Intrahemocoelic Within the hemocoel or perivisceral
cavity of an invertebrate. As in "intrahemocoelic injection." Invasion The penetration by a microorganism
of the integument and other epithelial barriers of the body of a host
organism. "Primary
invasiveness" is a property of pathogenic microorganisms. Invertebrate collagen Fibrous supporting material that stains like vertebrate
collagen and exhibits varying periodicites unlike that of vertebrate
collagen. Sometimes produced following
injury in mollusks, echinoderms and some other groups. Iridescent virus disease A disease of
Diptera, Lepidoptera, and Coleoptera, caused by large icosahedral viruses. The larval fat body appears to be the
principal site of virus multiplication, but the virus seems to multiply also in
other tissues. Multiplication of the
virus is confined to the cytoplasm.
Diseased larvae show a marked opalescence, which is particularly intense
in the fat body. The pellets of virus
purified by centrifugation reflect strongly iridescent light. The virions are about 130 millimicrons in
diameter. Isle of Wight disease Under this name
were included several maladies of adult honey bees having analogous symptoms
and said to have reached epizootic proportions in the British Isles between
1905 and 1919. Some authors believe that
the acarine disease was the principal, if not the only, constituent of the Isle
of Wight disease. Other authors believe
that the Isle of Wight disease might have been a type of dysentery or some
malady of the digestive system caused by poisoning or malnutrition. Use of this disease name is not recommended. See Acarine disease. Isolate (1, noun) pure culture of microorganism
obtained from some natural substrate. (2, verb) To separate,
to free from contaminants. To
obtain in pure (or axenic) culture, i.e., free from associated (micro)
organisms. J Japanese gypsy-moth disease A disease of
larvae of Porthetria dispar (Linnaeus) presumable caused by the
bacterium Streptococcus disparis Glaser. The affected larvae cease to eat and become
diarrheic. In the late stages of the
disease, the Streptococcus is found in the hemocoel and the insect's
muscle tissue gradually disintegrates in a rather characteristic fashion. Jaundice Nucleopolyhedrosis of the
silkworm, Bombyx mori (Linnaeus).
See also Grasserie. Juvenile stage This term denotes
any postembryonic stage in the development of an organism that precedes the
sexually mature adult stage. The term
"juvenile" implies a form similar to the adult, except as regards
size and the reproductive structures, whereas the term "Larva"
implies a postembryonic stage that differs markedly from the parents in
morphology. A larva attains the adult
morphology by a process of metamorphosis. K Karyogamy Fusion of two
haploid nuclei to form a synkaryon or zygote.1 Koch’s postulates A stepwise
procedure for establishing a suspected causal relation between a given
microorganism and a particular disease:
1) the microorganism must be present in every case of the disease; 2)
the microorganism must be isolated in pure culture; 3) the microorganism in
pure culture must give rise to the disease when a susceptible animal is exposed
to it; 3) the same microorganism must be present in, and recoverable from, the
experimentally diseased animal. Krebspest A disease of the European freshwater
crayfish, Astacus fluviatilis Fabricius. In the 1800's, a prolonged epizootic of
krebspest virtually wiped out commercial use of Astacus. It is caused by a fungus, Aphanomyces astaci
Schikora, which has a predilection for nervous tissue. L Lag phase Latent period at the beginning of the growth phase of
microorganisms. Larval equivalent In a given host-pathogen system, the mean
number of pathogen units that can be produced in one living host, usually the
larva of a holometabolous insect, under mass-rearing conditions; this is usually
for the purpose of field application of the pathogen units for the purpose of
microbial control, e.g., spraying at 250 larval equivalents (L.E.) per hectare. Latent infection An
inapparent infection in which the pathogen is still present in a noninfective
phase, and in which a certain pathogen-host
equilibrium is established. The
adjective "latent" is reserved to qualify "infection," thus
one speaks of "a latent infection" but not of "a latent
virus" (see Occult virus). LC50 See Median lethal concentration. LD50 See Median lethal dose. Lectin A molecule which carries sites which
combine with carbohydrate moieties (which may or may not be membrane bound). Lesion (1) A wound or injury. (2) Any more or less circumscribed pathologic
change in the tissues, including a change or loss of function. See also Biochemical lesion. Leucocyte (Leukocyte, Hemocyte, and
Amebocyte). A general
term for colorless blood cells in non-arthropod invertebrates that do not
contain a respiratory pigment.
Such cells are typically capable of amoeboid movement and phagocytic
activity during some stage(s) of their development. They wander freely through the hemolymph,
loose connective tissue and epithelial surfaces, especially in mollusks. Leucocytes are considered to be
multifunctional, participating in a variety of activities including wound
repair, shell repair, gamete resorption, calcium and other ion transport,
glycogen storage and transport, initiation of encapsulation and cellular immune
reactions. Leucocytes and hemocytes are currently classified as either
granulocytes or hyalinocytes depending on the presence or absence of
cytoplasmic granules (see those entries for a complete description). Leukocyte See Leucocyte, Coelomocyte and
Hemocyte. Leukocytosis Especially in bivalve
mollusks, the local increase in numbers of blood cells in tissues or blood
vessels through migration. It is a
response to injuries caused by physical or biological agents. Also termed Leukocytic
infiltration. Leukodermia A disease, possibly microbial in origin,
of Achatina fulica Bowdich, the giant African snail, and perhaps
of other snails. It is characterized by
destruction of dermal melanophores and of other superficial tissues. Visceral lesions may also occur. Life cycle The complete
sequence (or series of sequences) of morphological patterns within the cyclic
development of an organism. Although in
higher animals it starts with the zygote and ends with production of a new
generation of gametes, in microsporidia the situation is more complicated. In species with diplokarya the life cycle
seems logically to start with formation of the first diplokaryotic cell
(meront) by plamogamy and nuclear association.
In species without diplokarya the logical starting place is less evident. In microsporidia generally, it is convenient,
if not otherwise logical, to treat the sporoplasm that infects a new host
individual as the starting point of the life cycle.1 Linthal bees See White head. Lipopolysaccharides Cell wall components and pattern
recognition molecules typical of Gram negative bacteria. Lorsch disease A rickettsial
disease of the larvae of may beetles and june beetles (species of Melolontha
and of Amphimallon), as well as other related scarab larvae. The causative agent is Rickettsiella Melolonthae
(Krieg) Philip. LT50 See Median
lethal time. Lysozyme A cationic, low molecular weight enzyme
found in hemocytes and secretions of many invertebrates that mediates lysis and
destruction of bacteria. M Macroconidium (plural: -ia) Among fungi, a term
referring either to the larger of two morphologically distinguished and
markedly different sized conidial types produced by some fungi (e.g., species
of Fusarium). Macrogamete Larger one of the
pair of anisogametes considered female. Macronucleus Transcriptionally active
nucleus of ciliates, responsible for organism’s phenotype. Maladie a fuseaux See Spheroidosis. Maladie du pain d'epices Gingerbread disease. In oysters, involving the shell, and caused
by activities of species of Cliona, boring sponges. Maladie du pied A disease of
European oysters, Ostrea edulis Linnaeus. The etiologic agent, apparently a boring
fungus, causes formation of rubbery spots on the shell, pathological changes in
the tissues, and calcareous deposits on the adductor muscle scar. Death is caused by improper shell closure. Malaya disease A lethal
disease of larvae of the Indian rhinoceros beetle, Oryctes rhinoceros
(Linnaeus), caused by a virus. The
diseased larvae cease to feed, and they appear shiny, turgid (dropsied), with
enlarged, waxen abdomens. Rectal
prolapse may occur. In the last stages
of the disease, just before death, the larvae are totally lethargic. Virus multiplication occurs chiefly in the
nuclei of the fat-body cells. The rod-shaped
virions measure approximately 70 by 200 millimicrons. Malpeque bay disease An infectious
disease of undetermined etiology of the American oyster (Crassostrea virginica)
in the Gulf of St. Lawrence, Canada.
First appeared as an epizootic causing mass
mortalities in Malpeque Bay, Prince Edward Island, in 1915. Is characterized grossly by
marked weight loss in affected oysters, stunted growth, yellow-green pustules,
spawning failures and high mortalities.
Genetically resistant strains of C. virginica have arisen
from survivors of the epizootics, but imported stocks continue to suffer high
mortality rates. MAP kinases Mitogen activated
protein kinases are involved in molecular signal transduction pathways; they
play roles in diverse pathological physiological responses. Maturation immunity A decrease in
susceptibility coincident with the development of an animal to maturity. Maturation phase In virus
infections, a phase or period following the eclipse period, during which
infective particles are completed. See
also vegetative phase. Maximal nonlethal dose The dose which
will just fail to kill all or most of the subjects of a given species or
strain. (The use of this term is not
recommended, as it does not take account of the variation in tolerance within a
species or strain.) May disease Rather than a single
disease, may disease is a group of maladies of adult honey bees having similar
syndromes but different etiologies. Saccharomyces
apiculatus Hansen, for instance, has been found in bees afflicted with
constipation, and it has been considered as the sole cause of a may disease.
Collection of buttercup pollen may be the cause of another malady called
Bettlach may disease. Maya's disease A lethal
disease of larvae, pupae, and adults of rhinoceros beetles (Oryctes) and
of other scarabs. The etiology of Maya's
disease is unknown. The appearance of a
multitude of spheroid vacuolated inclusions in the fat body of diseased insects
is the most striking sign of the malady.
Large numbers of these inclusions may entirely fill the volume of the
fat body, pericardial cells, and tracheal matrix. In adults, the thoracic muscles are also
affected. Mechanical vector See Transport
host. Median effective dose The dose which
will produce a response in half the test subjects. The chief characteristic of this dose is that
it is an indirect measure of the mean tolerance of a batch of test
subjects. Its symbol is ED50. The median lethal dose (LD50) is a
special case, in which death is the response. Median effective time The time at which
a response occurs in half the test subjects after exposure to a pathogenic
(including toxicological) stimulus. Its
symbol is ET50. The median
survival time (ST50) is a special case, in which death is the response.
(Estimation of this parameter by probit analysis, general linear models, and
certain other statistical methods is generally invalid because the data are
usually censored [see censored data] and assumptions of independence and normal
distribution of data are almost always violated.) (See survival data). Median lethal concentration A concentration
of a pathogen or agent which will produce death in half the test subjects; the
experimental method is not sufficiently accurate to determine the precise dose
to which the test animals were exposed.
Its symbol is LC50. (contrast with median lethal dose) Median lethal dose A more
restricted concept of Median effective dose.
The dose which will produce death in half the test
subjects. Its symbol is LD50. Median lethal time In a
time-dependent biological assay procedure, this is the period of exposure to a
pathogenic (including toxicological) stimulus which will produce death in half
the test subjects. The length of
exposure is a direct measure of dosage, and an increase in the period of
exposure results in an increase in uptake and true dose in the same ratio. Its symbol is LT50, not to be
confused with the Median Survival time (ST50). (Estimation of this
parameter by probit analysis, general linear models, and certain other
statistical methods is generally invalid because the data are usually censored
[see censored data] and assumptions of independence and normal distribution of
data are almost always violated.) (See
survival data). Median survival time A restricted
concept of median effective time. The time at which death occurs in half the test subjects after
exposure to a pathogenic (including toxicological) stimulus. Its symbol is ST50, not a direct
measure of dosage, and it is not to be confused with the Median Lethal Time (LT50),
which is a direct measure of dosage. (Estimation of this parameter by probit
analysis, general linear models, and certain other statistical methods is
generally invalid because the data are usually censored [see censored data] and
assumptions of independence and normal distribution of data are almost always
violated.) (See survival data). Meiospore A spore usually containing a
single haploid nucleus (rarely two or more nuclei), and formed on or in the
cell in which meiosis occurred, an usually formed shortly after completion of
meiosis. In some organisms, one or more mitotic divisions may occur before
meiospores form. Examples of meiospores among fungi include ascospores and
basidiospores. Melanization Deposition of the dark
pigment, melanin, and associated materials on the surfaces of foreign objects,
both biotic and abiotic. Often accomplished by hemocytes as a response to injury or to the
presence of a parasite. Common in arthropods. Melting brood See European foulbrood. Meridic Pertaining to a medium
(used for growing organisms) in which the chemical identity of certain, but not
all, of the absolutely essential molecules has been established. See also holidic and oligidic. Merogonial plasmodium A presporogonic
individual with more than two diplokarya, rarely more than eight, as the result
of delayed cytokinesis during merogony.1 Merogony An indeterminate series of binary
divisions of diplokaryotic cells (meronts), sometimes with delayed cytokinesis
and production of transitory paucinucleate plasmodia.1 Meront In microsporidia, diplokaryotic
presporogonic stages of variable size.1 Merozoite Stage of an
intracellular sporozoan that is produced by merogony and develops into a
meronts or gamont.2 Metabolism The entirety of biochemical proceedings of an organism
needed for the vital process and new cell substances Metabolite Low molecular nutrient or product participating in
metabolism. Metabolome The entirety of all metabolites of an organism or cell. Metabolomics Research dealing with metabolites. Metastasis (1) The transfer of pathogenic
microorganisms to parts of the body remote from the original foci of
infection. (2) The transfer of malignant
tumor cells from one organ or part to another, where they grow and form
secondary tumors. (3) A secondary
tumor. Plural,
metastases. Metastasize To form metastases. Microbial control That part of
biological control concerned with controlling insects (or other organisms) by
the use of microorganisms (including viruses).
Pathogens may exert their controlling effect by means of their invasive
properties, by toxins, enzymes, and other substance. Some authors limit the term to that phase of
biological control concerned with the use of microorganisms for the control of
insects (or other forms of life). Microbial insecticide A pathogenic
microorganism or its products (toxins, etc.) used to suppress an insect
population. The terms "microbial
pesticide," "biotic insecticide," and "microbial control
product" are also used. (See also Biotic insecticide.) Microbial persistence A phenomenon
characterized by the continued presence of a pathogenic microorganism within
the host in the absence of overt disease but following an episode of overt
disease. Microbiota The combined microflora and
microfauna of an organism. Or, the
microflora or microfauna considered separately. Microconidium (plural: -ia) Among fungi, a term
referring either to (a) the smaller of two morphologically distinguished and
markedly different sized conidial types produced by, for example, species of Fusarium (whose macroconidia are
multicellular and curved). Microfeeding A term sometimes used to designate
forced feeding of small volumes of solutions or suspensions to insects and
other small animals. Peroral
inoculation, using microcatheters.
By some, microfeeding is used to indicate active eating of small
measured amounts of fluids or solids. Microgamete Smaller one of the
pair of anisogametes considered male.2 Microinjector A device for injecting measured, minute
amounts of fluids. Composed
usually of a fine metal or glass needle adapted to a syringe, and of a
mechanism for the advancement of the piston (micrometer or ratchet). Micronucleus Transcriptionally inactive
nucleus of ciliates, serving as a repository of the unaltered germ line. Typically smaller than macronucleus.2 Micropyle Opening in the wall
of a sporozoan oocyst.2 Microsporidosis Infection with
microsporidia. Microsymbiont This term is sometimes used to designate
the smaller organism, or microorganism of a symbiotic association. See also Symbiont. Mictosporoblastic Pertaining to a
microsporidian sporont that produces a variable number of sporoblasts.1 Milky disease Any of a group of
maladies of scarabaeid larvae, caused by species of the genus Bacillus. Type A milky disease of the white grub of the
Japanese beetle (Popillia japonica Newman) is caused by Bacillus
popilliae Dutky, whereas type B milky disease (marked by extensive
formation of blood clots, impairment of circulation, and gangrene of the
appendages) is caused by Bacillus lentimorbus Dutky. Milky diseases of types A and B occur in
numerous other species of scarabs. As
the disease progresses, the bacteria multiply and sporulate in the insects'
blood to produce marked turbidity of the normally clear fluid. The milkiness of the blood at this stage is
the basis for the name "milky" disease. Minimal lethal dose According to the most
common use in the literature, this is the dose just sufficient to kill all or
most subjects of a given species or strain.
The use of this term is not recommended (see Maximal nonlethal dose). Mitotic recombination (=
parasexuality) When genetic recombination occurs in vegetative cells of fungi
(or other organisms), usually understood to involve nuclear fusions followed by
(presumably) meiotic rehaploidizations that do not occur in the usual sexual
organs. Mixed infection Concurrent infection by
two or more pathogenic microorganisms.
Compare with secondary infection. Mode of action The manner or way of a bioactive substance to be active. Molecular modelling Term for the computer-based calculation and preparation of molecular
structures. Monoclonal Antibody Antibodies of the same kind reacting with the same antigenic
determinant.
Monoinfection
Infection by one species of pathogen. Monoxenous Having a single
taxonomic species of host (i.e. “host species-specific”).2 Morbid drone-laying A disease of
queen honey bees, of unknown etiology.
Properly mated queens, in the first or second year of life and long
before their supply of spermatozoa is exhausted, become drone layers
("drone-broody" queens) and lay unfertilized eggs into the cells
reserved for worker bees. The epithelial
cells of the spermatheca of the affected queens contain intranuclear
acidophilic inclusion bodies. The
spermatozoa within such spermathecae curl into ringlets and degenerate. Each ringlet consists of only one
spermatozoon (Arnhart's "ringelsamen"). Drone broodiness. Morbidity See Incidence (of a disease). Moribund Dying.
Near death. Morison's cell inclusions Strongly basophilic
cytoplasmic inclusions appearing in the hindgut epithelium of bees showing
symptoms of chronic paralysis. The
inclusions are largest in the cells immediately posterior to the openings of
the malpighian tubules. Morphallactic regeneration
(morphallaxis) The process by which damaged tissues of
lost parts are renewed or replaced by reorganization of the renewing part(s) of
the body of an organism. This is
achieved simply by reorganizing the old tissues directly into the new without
augmenting the number of remaining cells.
It involves the rearrangement of remaining parts so as to remodel an
amputated structure into an integrated morphological whole. Morphopathology That branch of pathology dealing with
the morbid changes occurring in the structure of cells, tissues, and organs, as
distinguished from physiopathology. Mortality rate Death rate. The number of deaths per
unit population during a given period of time. If all deaths from all causes are counted
(e.g., during 1 month), the rate is referred to as the "crude mortality
rate" or "crude death rate."
Often the death rates are calculated for specific causes, and they are
referred to as "cause-specific mortality rates." MP variant Many
polyhedra variant. A
plaque variant of certain nucleopolyhedrosis viruses which forms many polyhedra
in the nuclei of susceptible cells in vitro. Compare with FP variant. MSX disease
A code name,
meaning "multinucleated sphere of unknown affinities." Found in the American oyster, Crassostrea virginica, on the Middle
Atlantic Coast of the U.S.A. caused by Haplosporidium nelsoni, which lives in the
connective tissues surrounding the gut.
MSX disease is a cause of serious mortalities in high-salinity areas
during late summer and early fall. Mucocalyx A mucus layer on the surface of
the exospore in some species of microsporidia.1 Multicapsid virion A cluster of
nucleocapsids enclosed within a single envelope. Also designated
Multiple-capsid virion or Bundle virion (e.g. some baculovirus). Multiple division Simultaneous division of a
plasmodium into as many uninucleate cells as there were nuclei in the parent
body.1 Multiple-capsid
virion See Multicapsid
virion. Multisite inhibitor Inhibitory substance with an effect on different molecular
targets. Multivoltine (plurivoltine)
Species with several generations per year are multivoltine. Mummification Dehydration of animal body after death. Muscardine fungus An old and now little used term
generally referring to fungi that substantially or completely cover a mycotized
host cadaver; the term is usually modified as “[white, green, red, yellow or
some other color] muscardine” to refer to particular types of mycoses. A
mycosis of silkworm larvae, muscardine of the silkworm, is caused by Beauveria
bassiana (Balsamo) Vuillemin. In sericultural practice, the disease is
transmitted from one generation of silkworms to the next by the conidia which
have accumulated in neglected rearing rooms. Agostino Bassi, the "founder
of parasitology," was the first to prove, in 1834, that the muscardine of
the silkworm is contagious and that the fungus is the causative agent of the
disease. Mutagen Mutation inducing agents. Mutation Modification of the heritable information of an organism. Mutualism A symbiotic relationship between two
different species in which both jointly benefit. Usually obligatory. Mycelia Sterilia An
antequated and no longer officially recognized term for (usually
basidiomycetous or ascomycetous) fungal mycelia that do not produce any sorts
of spores and are, therefore, not subject to standard identifications. If
referring to a single such fungus, it should be referred to as a sterile
mycelium. Mycelium Mass of hyphae constituting the body
of a fungus. Mycethemia The presence of a fungus or some of
its stages in the circulating blood of an animal. Mycetocyte A cell containing intracellular
microsymbionts. One of
many cells making up the mycetome. Mycetome An organ in a variety of invertebrates
(especially in Hemiptera) whose cells contain fastidious, mutualistic or
commensalistic bacteria; mycetomes are usually modifications of cells in the
fat body. The cells making up the mycetome and containing the bacteria are
known as mycetocytes. Mycobiota Community of fungi. Mycoinsecticide Insecticide based on a
fungal active ingredient. Mycopesticide Pesticide
based on a fungal active ingredient. Mycosis Fungal disease. Any disease caused by
the presence of fungi. Mycotoxicosis A disease caused by the action of a
mycotoxin. See Toxinosis, Toxemia. Mycotoxin A toxin produced by fungi. Myiasis A condition deriving from infestation by
parasitic flies. See also Apimyiasis. N Natural host A host
in which the pathogenic microorganism (or parasite) is commonly found and in
which the pathogen can complete its development. The term "natural host" implies
that the host is the usual one and is synonymous with "typical host."
Necrotize To kill cells and tissues in a
living organism. Nematodiasis Infection by a nematode parasite. Nematophagous A broad term referring to a microbe
(fungus, bacterium, etc.) routinely able to utilize nematodes as a food source.
Most often used in reference to fungi that are either predatory (see predaceous)
or are endoparasites (endopathogens) that enter through the gut or cuticle,
develop internatlly, and then usually sporulate outside the diseased cadaver of
the host. Neoplasm An abnormal mass of tissue not required
for the repair of organs, the growth of which exceeds and is uncoordinated with
that of the normal tissues and persists in the same excessive manner after
cessation of the stimulus which evoked the changes in growth pattern. Neoplasms may be benign or malignant. "Cancer" refers to any type of
malignant neoplasm. New York bee disease See European
foulbrood. Nick translation A procedure for the radioactive labelling of the DNA Nodule formation In arthropods,
this process is performed by hemocytes through a mixture of phagocytosis,
aggregation and encapsulation. A clump
of hemocytes and debris forms in the blood and at its fullest expression the
nodule consists of a lamellated capsule of hemocytes merging into a center of
degenerating hemocytes, foreign particles and other debris that is often
clothed in melanin. Nodule See Nodule formation. Noninclusion See Nonoccluded. Noninfectious disease any disease in
which a living microorganism is not involved. Nonoccluded Said of those viruses in which the
virions are not occluded in a dense protein crystal. Preferable to "noninclusion.: Nonpermissive cells Cells that accept
viral nucleic acid into their genome but do not permit the assemble of
infectious virions. Nonvirion antigen A protein
produced by a cell that has been infected by a virus. The antigen, while specific for that virus,
is not a structural part of the virus itself. Normal host This ambiguous
term should be avoided. It has been used
as a synonym for "Typical host" and "Natural host," which
are the preferred terms. Northern blot A procedure to transfer RNA from a gel to another matrix e.g.
Nitrocellulose. Nosema disease Infection of adult bees
by Nosema apis Zander. The
microsporidan develops in the cytoplasm of the midgut epithelial cells. It causes no outward symptoms but appreciably
shortens the lives of bees. Infected
colonies can survive indefinitely, but sometimes become severely infected,
dwindle and die. "Nosema
disease" is sometimes used in referring to diseases caused by other
species of nosema infecting other species of insects. Nosemosis is a preferred term in these
instances. Nosemosis Infection with
microsporidia of the genus Nosema. Nosography A branch of pathology that deals with
the description of diseases. Nosology A branch of pathology that deals with
the classification of diseases. A treatise comprising such a classification. Nuclear association Pairing of two haploid nuclei following
plasmogamy, at
the end of the haplophase, to form a diplokaryon. A form of diplosis in the microsporidia.1 Nuclear dissociation Separating of the two
members of a diplokaryon to form two independent haploid nuclei. One of two methods of haplosis in
microsporidia, the other being meiosis.1 Nuclear polyhedrosis See
Nucleopolyhedrosis. Nuclease Catabolic enzyme hydrolysing
phosphodiester bonds in nucleic acid. Nucleocapsid The structure composed of the capsid
with the enclosed viral nucleic acid.
Some nucleocapsids are naked, others are enclosed in an envelope (or
limiting membrane). See also Capsomere,
Virion. Nucleopolyhedrosis A viral disease of insects, mainly the
larvae of certain lepidoptera and hymenoptera, characterized by the formation
of polyhedral inclusion bodies (polyhedra) in the nuclei of the infected
cells. The virus
multiples in the epidermis, tracheal matrix, fat body, and blood cells of
lepidopterous larvae. In
hymenopterous larvae the virus proliferates in the midgut epithelium. The disease is usually fatal. Synonymous with Nuclear
polyhedrosis. See also Grasserie,
Jaundice, Polyhedrosis, Wilt Disease, Wipfelkrankheit. O Occluded Viruses in which the virions are
occluded in a dense protein crystal, large enough to be visible in the light
microscope (e.g., polyhedrosis viruses, granulosis viruses). Occlusion body A
virus-directed structure that is assembled within the infected cell and
contains or occludes infectious virus particles or virions. Occlusion bodies
may contain one or many virions depending on the type of virus. In the case of
the Baculoviridae, occlusion bodies are assembled in the nucleus (NPVs) or the
mixed nuclear-cytoplasmic contents after loss of the nuclear membranes.
Baculovirus occlusion bodies may contain one or many virions. Occult virus A
special phase of some viruses, characteristic of latent infections, in which
the pathogenic agent is presumed to differ from the infective phase, and in
which virions cannot be detected.
Synonymous with but preferable to "hidden virus" and
"masked virus" (see Latent infection). The occult phase of a virus should not be
confused with the eclipse, which is a normal phenomenon during viral
replication. Octosporoblastic Pertaining to a
microsporidian sporont that produces eight sporoblasts.1 Oligidic Pertaining to a medium
(used for growing organisms) consisting wholly or largely of crude materials,
in which no molecule (other than water) has been established as an absolute
nutritional requirement. See also
Holidic, Meridic. Oomycetes A large group of pseudofungi once treated
amongtrue fungi but now classified in the Kingdom Chromista (= Straminipila)
because one of the two flagella on their zoospores and planogametes is of the
tinsel-type (covered with hair-like mastigonemes). Oospore Thick-walled spore which develops in
the female gametangium of oomycetes (Lagenidium,
Pythium, Saprolegnia, etc.) through either fertilization or parthenogenesis. Oosporein A red pigment
produced by numerous fungi (especially ascomycete entomopathogens related to Cordyceps) the may cause a strong pink
to red coloration of infected hosts or of culture media. Operculum Lid or covering
flap found in various groups of protozoa.2 Organ culture The maintenance
or growth of organ primordia or the whole or parts of an organ in vitro in a
way that may allow differentiation and preservation of the architecture and/or
function. See also Cell culture, Tissue
culture. Overt disease A disease with
detectable pathologic effects. P Pansporoblast In distinction from the sporoblasts
which result from the segmentation of the pansporoblast. Exact synonym of “sporont” as used with the
microsporidia, the latter term now preferred.1 Pansporoblast[ic] membrane
An interfacial
envelope produced by the pansporoblast (sporonts).1 Panzootic Denoting a disease affecting all, or a
large proportion of the animals of a region.
Extensively epizootic. Paralysis, acute See acute
paralysis. Paralysis, bacillary See bacillary
paralysis. Paralysis, chronic See chronic
paralysis. Paramoeba disease See
Paramoebiasis. Paramoebiasis A disease of the blue crab, Callinectes
sapidus Rathbun, that causes severe mortalities in crabs captured during
the early summer in certain high-salinity areas along the mid-Atlantic
coast. It is caused by a protozoan, Paramoeba
perniciosa Sprague, Beckett, and Sawyer.
The parasites live in connective tissues and hemal spaces, spilling over
in large numbers into the circulating blood during the terminal phase of the
disease. Paramural body A sac-like invagination of the
plasmalemma of a dividing
individual, containing a whorl of tubular structures, adhering to the cleavage
furrow and participating in the cleavage process.1 Parasagittal
section A
section of an animal parallel to the sagittal section. Parasexuality see Mitotic recombination Parasite An organism that lives at its host's expense,
obtaining nutriment from the living substance of the latter, depriving it of
useful substance, or exerting other harmful influence upon the host. Parasitic Microbe living in or
on another organism at the expense of that host, usually invading the host body
and causing disease. A functional distinction is made, however, since parasites
will not usually cause the mortality of the host. Parasitic castration Any process that
interferes with or inhibits the production of nature ova or spermatozoa in the
gonads of an organism. (The term is not
limited to meaning the sudden and complete extirpation of the gonads.) Parasitism A symbiotic relationship between
individuals of two different species in which the host is harmed and the
parasite benefits. Parasitoid An insect with a larval stage that
feeds inside or outside of a host insect’s body resulting in the death of the
host. The adult parasitoids are free-living. |