Technical Bulletin 218 - Glossary aerosol - A colloid of liquid or solid particles suspended in a gas, usually air. antiserum - A preparation of serum containing antibodies specific for a particular antigen, i.e., immunogen. A therapeutic antiserum may contain antitoxin, antilymphocyte antibodies, etc. asymptomatic - Showing or causing no symptoms atrophy - Diminuation in the size of a cell, tissue, or organ that was once fully developed or normal sized. azygospore - A zygospore that develops parthenogenetically (development of sexual reproduction from the female gamete alone). bacteria - Small relatively simple prokaryotic microorganisms. blastopore - An asexual spore formed by budding. capillispore - A special type of secondary conidium, which is produced on a slender capillary tube (conidiophore) developing on primary or secondary conidia. chronic disease - Of long duration. Not acute. conidiophore - A specialized hypha bearing conidia. conidium - A spore formed asexually, usually at the tip or side of the hypha. contamination - The harboring of or contact with microorganisms (or other organisms such as insect parasites) in abscence of a relationship that may be considered commensalistic, mutualistic, or parasitic. cytopathology - The study of cells in disease; cellular pathology. Dalton (Da) - A unit of mass, being one sixteenth of the mass of the oxygen atom, or approximately 1.65 x 10-24 gram. diagnosis - To distinguish one disease from another. The determination of a disease from its signs, symptoms, etiology, pathogenesis, physiopathology, morphopathology, etc. Also, the decision reached. disease -"Lack of ease." Departure from the state of health of normality. The 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. eclipse period (phase) - The time between the penetration of a virus into a cell, when it appears to lose infectivity, and the appearance of newly synthesized infectious virus. endoparasite - A parasite that lives within the body of its hosts. endospore - A resting stage produced internally by some bacteria, which is resistant to unfavorable conditions. endotoxin - Substances produced by microorganisms that are not secreted into the surrounding medium but are confined within the microbial cell. They are released after autolysis. epizootic - The widespread occurrence of an animal disease. eukaryote - A cell or organism with a true nucleus containing chromosomes encircled by a nuclear membrane. exotoxin - Poisonous substances produced by the microbial cell and liberated into the surrounding environment, without destruction of the cell. (Also called "ectotoxins," "true toxins," and "soluble toxins.") facultative parasite - An organism capable of infecting other live or dead organic matter, according to circumstances. feral - Wild, savage, or deadly. fission - The splitting of a cell into two cells directly. flacherie - 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 l arval tissues. flacherie, touffee - A noninfectious flacherie of the silkworm, known to appear in rearing establishments after sudden abnormal increases in environmental temperature and humidity ("touffee," meaning "wisps of heat"). Fifth-i nstar larvae are particularly affected by touffee flacherie. flacherie, viral -An infectious flacherie of silkworm larvae caused by a small nonoccluded virus. flagellum - A hair-, whip-, or tinsel-like structure that serves to propel a motile cell. flash sterilization - Flash sterilizers operate on the principle that a thin layer of medium moves rapidly through a heat exchanger maintained at a high (145-160°C) temperature. Time required for complete sterilization of heliothine's diet by this method is 2-3 minutes. This method renders the diet sterile without the addition of antimicrobials. fungus - One of the achlorophyllous thallophytes whose somatic structures are usually filamentous and branched. Fungi have cell walls and demonstrable nuclei. They reproduce typically both by sexual and asexual means. genetic engineering - Microorganisms can be altered by the movement of genes or genetic material from one organism to another so that the recipient organism expresses a different attribute. gram-negative - Losing the stain or decolorization by alcohol in Gram's method of staining, a primary characteristic of certain microorganisms. gram-positive - Retaining the stain or resisting decolorizing by alcohol in Gram's method of staining, a primary characteristic of certain microorganisms. Heliothinae - A subfamily of Noctuidae. HEPA filters - High efficiency particulate air filters. histopathology - A study of abnormal microscopic changes in the tissue structure of an invertebrate animal (or other organism). hyperplasia - An increase in the number of functional units of an organ (organelles, cells, or tissues), excluding tumor formation, whereby the bulk of the organ is increased in response to increased functional demands. Also see hypertrophy. hypertrophy - An increase in size (weight) and functional capacity of 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. Also see hyperplasia. hypha - The unit of structure of the fungi; a tubular filament. hyphal body - A fragment of the mycelium of the Entomophthorales. in vitro - In the "test tube" or other artificial environment, outside the living organism. in vivo - In the living organism. inapparent infection - An infection that gives no overt sign of its presence. 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 pathological effects (or overt disease ). In the case of the viruses, an infection has been defined as the introduction into a cell or organism of an entity able to multiply, able to produce disease, and able to reproduce organized infective entities. karyogamy - The fusion of two nuclei. 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,& quot; thus one speaks of a "latent infection" but not of a "a latent virus." Also see occult. meconium - The substance excreted by certain metabolic insects soon after their emergence from the chrysalis or pupa. meiosis - A type of cell division occurring in diploid or polyploid tissues that results in a reduction in chromosome number, usually by half. merogony - The vegetative phase of microsporidia. During merogony, the microsporidium multiplies rapidly by binary fission, plasmotomy, or multiple budding. microbial control - The 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 t oxins, enzymes, and other substances. 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 als o used. micron (µm) - A unit of measurement equal to 0.001 mm or approximately 1/25,000 of an inch. muscardine - A term used generally in connection with those mycoses of insects in which the fruiting bodies of the pathogenic fungi (muscardine fungi) arise on the exterior of the insect, produce a thick covering about the animal. Specifically, the word muscardine was used in reference to the muscardine of the silkworm. The noun "muscardine," accompanied by a modifier, denotes specific mycoses of a number of insects, such as white muscardine of the chinch bug and green muscardine of th e European corn borer. mycelium - A mass of hyphae constituting the body (thallus) of a fungus. mycosis - Any disease caused by the presence of fungi. mycotoxin - A toxin produced by fungi. nanometer (nm) - A unit of length equal to one-billionth of a meter, or 10-9 meters. nematodes - Commonly referred to as roundworms, eelworms, or threadworms; are translucent, usually elongate, and more or less cylindrical throughout their body length. The body is covered by a noncellular elastic cuticle that differs chemically from the chitinous cuticle of arthropods. Nematodes have excretory, nervous, digestive, reproductive, and muscular systems but lack circulatory and respiratory systems. The alimentary canal consists of a mouth situated terminally, followed by the stoma or buccal cavity, and esophagus, intestine, and rectum with the anus opening ventrally. Sexes are usually separate. obligate parasite - An organism that can obtain food only from living protoplasm. Obligate parasites cannot be grown in a culture on non-living media. 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). 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 "h idden virus" and "masked virus." One speaks of an "occult virus" rather than a "latent virus" (see latent infection). The occult phase of a virus should not be confused with the eclipse, which is a normal phenomenon duri ng viral replication. parasexual recombination - The occurrence of nuclear fusion without proper meiosis. parasite - An organism that lives at the expense of another, usually invading it and causing disease. pathology - The science that deals with all aspects of disease. The study of the cause, nature, processes, and effects of disease. Any branch of science, or any technique, method, or body of facts that contributes to our knowledge of the nature and constitution of disease belongs in the broad realm of pathology. "Invertebrate pathology" refers to all aspects of disease (including abnormalities) that occur in invertebrate animals. Similarly, "insect pathology" is that branch o f entomology or invertebrate pathology that embraces the general principles of pathology as they may be applied to insects. If biology is defined as that branch of science that deals with the origin, structure, functions, and life history of organisms, th en pathology might be defined as "biology of the abnormal." For each branch of biology there is a corresponding branch of pathology. Also, in a more limited sense, pathology refers to the structural and functional changes from the normal. Also i n a limited sense, general pathology treats disturbances that are common to various tissues and organs of the body, such as degenerative processes, pigmentations, mineral deposits, circulatory disturbances, specific and nonspecific inflammations, progress ive tissue changes such as hyperplasia and hypertrophy, and tumors. pathogen - Any disease-producing microorganism or material. pathogenic - Giving origin to disease or morbid symptoms. pebrine - A disease of the silkworm, Bombyx mori, caused by the microsporidian Nosema bombycis. The appearance of dark pepper-like spots on the integument of the diseased larvae is a characteristic sign of the infection. Numerous e pizootic outbreaks of the disease occurred in the second half of the 19th century. per os - By way of or through the mouth, as in per os adminstration of a drug. plasmogamy - The fusion of two protoplasts. polyhedron - A crystal-like inclusion body (enclosing a number of polyhedrosis virus particles) produced in the cells of tissues affected by certain insect viruses. Ordinarily the polyhedrosis virus particles formed in the nuclei of the host cel ls are rod-shaped while those formed in the cytoplasm are polyhedral (many sided) or approximately spherical. Also see polyhedrosis; plural, polyhedra. polyhedrosis - A virus disease of certain insects characterized by the formation of polyhedral inclusions in the tissues of the infected insect. prokaryosis - The state of not having a true nucleus; the nuclear material's being scattered in the protoplasm of the cell. protoplast - The living portion of a cell considered as a unit; included the cytoplasm, the nucleus, and the plasma membrane. protozoa - The protozoa ("first animals") are a heterogeneous group of microorganisms of very diverse characters, behavior, and life cycles. The protozoa are minute unicellular organisms, sometimes designated as being acellular or nonc ellular. Most species produce chronic infections characterized by a general debilitation of the insect. saprobes - An organism that utilizes dead organic matter for food. schizogony - A type of multiple fission that occurs in the life cycle of several groups of protozoa including microsporidia. Multiple fission may occur in (1) sporogony (forming sporoziotes), (2) merogony (forming meroziotes), or (3) gametogony (forming gametes). septicemia - A morbid condition caused by the multiplication of microorganisms in the blood. septum - A cross-wall in a hypha. sign - Any objective aberration or manifestation of disease indicated by change in structure. sporangiospores - A spore borne within a sporangium. sporogony - The production of spores. sterile - The absence of all life on or in an object. This is an absolute term; there can be no such description as "nearly sterile," "partially sterile," etc. symptom - Any object aberration in function (including behavior), indicating disease. symptomology - The science that treats the symptoms and signs of disease. Also, the study of the aggregate of the symptoms and signs of a disease. Semiology. syndrome - A group of signs and symptoms characteristic of a particular disease. A running together of concurrence of symptoms associated with any morbid process. This is a trend toward considering as a "disease entity" any morbid proc ess that has a specific cause, while a "syndrome" reflects not so much specific disease factors as a chain of disrupted physiological processes. Thus, the same syndrome may arise from many different causes. teratology - The science concerned with malformations and monstrosities or serious deviations from normal structure. These abnormalities may be classified into various types or groups. Among the more common types of teratological changes in inse cts, for example, are prothetely (imaginal organs appearing in larvae), hysterotely (larval structures appearing in adults), and homoesis (one anatomical structure assuming the likeness of another). toxemia - A condition produced by the dissemination of toxins in the blood. viremia - The presence of virus in the hemolymph or blood. virion - The mature virus, the ultimate phase of viral development. The virion is either a naked or an enveloped nucleocapsid. The term 'virus' embraces all phases of the viral development, and it includes the viron. virulence - The quality or property of being virulent. The quality of being poisonous. The disease-producing power of a microorganism, i.e., the ability of a microorganism to invade and injure the tissues of its host. The relative capacity of a microorganism to overcome the body defenses of the host. The degree of pathogenicity (the ability to produce disease) within a group or species. Thus, one may speak of avirulent, virulent, and highly virulent strains within a group or species of microorganism that are said to be pathogenic. virus - Infectious units (obligate parasites) comprising either DNA or RNA enclosed in a protective coat. Their nucleic acid contains information necessary for their replication in a susceptible host cell. They contain non energy-producing enzyme systems, no functional ribosomes or other cellular organelles; these are supplied by the cell in which they replicate. The cell may also supply some of the enzymes necessary for viral replication. The host cell may or may not be destroyed in the process of viral replication and release. *Some material has been drawn from the following references: Alexopoulos, C. J. 1952. Introductory mycology. John Wiley & Sons, New York, NY. Cruse, J. M., and R. E. Lewis. 1995. Illustrated dictionary of immunology. CRC Press, Inc., Boca Raton, FL. Dorland's illustrated medical dictionary, 24th edition. 1968. W. B. Saunders Co., Philadelphia, PA.