Definitions

A. First lecture

Natural control

The maintenance of a more or less fluctuating population density of an organism within certain definable upper and lower limits over a period of time by the actions of abiotic and/or biotic environmental factors.

Biological control

The action of parasites, predators, or pathogens in maintaining another organism's population density at a lower average than would occur in their absence.

Strategy

A plan or technique for achieving some end.

Tactic

A planned action or maneuver for accomplishing an end.

B. Subsequent lectures

Acute

Short duration; characterized by sharpness or severity.

Axenic

Free from associated organisms.

Bacteremia

The presence of bacteria in the hemolymph or blood of animals without production of harmful toxins or other deleterious effects.

Baculovirus

A group of viruses that infect insects; has double-stranded DNA, rod-shaped. Includes the nuclear polyhedrosis, granulosis, and Oryctes viruses.

Biotic insecticide

An organism used to suppress a local insect pest population. Also bioinsecticide or biopesticide. See microbial insecticide.

Capsid

The protein coat or shell of a virus particle.

Capsomere

A cluster of structure units arranged on the surface of a nucleocapsid.

Capsule

The protein material surrounding the granulosis virus rod. Also referred to as granule. Protein is called "granulin."

Chronic

Of long duration; not acute.

Congenital disease

One that is present in an animal at birth.

Contagious disease

A disease that is naturally transmitted by contact, either direct or mediate.

Disease

"Lack of ease." Departure from the state of health or normality. Disease is a process, not a thing and represents the response of the body to injury or insult.

Endotoxin

A poisonous substance produced by microorganisms that is not secreted into the surrounding medium but confined within the microbial cell.

Entomogenous

Organisms growing in or on the bodies of insects.

Entomophagous

Insectivorous; consumption of insects.

Entomopathogenic

Insect-killing.

Entomophilic

Association between insects and other organisms; "insect-loving."

Enzootic disease

A disease usually in low prevalence which is constantly present in a population.

Epizootic

An outbreak of disease in which there is an unusually large number of cases.

Epizootiology

The field of study concerned with the study of diseases of animals on the basis of mass phenomena. (Epidemiology used for human situations).

Etiology

The study of the causes of disease.

Exotoxin

A poisonous substance produced by the microbial cell and liberated into the surrounding environment without destruction of the cell.

Granulosis

A virus disease of certain lepidopterous insects characterized by the presence of minute granular inclusions (capsules). It contains double-stranded DNA and is one of the baculoviruses.

Incidence

The number of new cases of a particular disease within a given period of time in a population being studied.

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.

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.

Infectious disease

Disease caused by the actions of a living organism.

Intoxication

Poisoning.

Microbial control

That part of biological control concerned with controlling insects (or other organisms) by the use of microorganisms.

Microbial insecticide

A pathogenic microorganism or its products used to suppress an insect population.

Moribund

Near death.

Occlusion body

Made up of proteins that surround the nucleocapsid. Called polyhedra for those surround the nuclear polyhedrosis viruses, granules or capsules that surround the granulosis viruses.

Panzootic

Denoting a disease affecting all or a large proportion of the animals in a region.

Pathogen

A specific cause of disease by a microorganism.

Pathogenicity

The quality or state of being pathogenic. Applied to groups or species of microorganisms, whereas virulence is used in the sense of degree of pathogenicity within the group or species.

Pathology

The science that deals with all aspects of disease.

Peplomer

Envelope around a virion derived from the plasma membrane with spikes at one end that serves as attachment to cells.

Period of lethal infection

The time interval between invasion by a microorganism and death of the host.

Polyhedron

Crystalline inclusion body produced in the cells of tissues affected by certain insect viruses. In nuclear polyhedrosis viruses, the protein is forms the polyhedron is called "polyhedrin."

Polyhedrosis

A virus disease of certain insects characterized by the formation of polyhedral (occlusion bodies) inclusions in the tissues of the infected host.

Portal of entry

Point at which the invading microorganism enters the body of the animal.

Prevalence

the total number of cases of a particular disease at a given moment in time, in a given population.

Septicemia

A morbid condition caused by the multiplication of microorganisms in the blood; toxins are produced. See bacteremia.

Sign

Any objective aberration or manifestation of disease indicated by a change in structure.

Symptom

Any objection or aberration in function including behavior indicating disease.

Syndrome

A group of signs or symptoms characteristic of a particular disease.

Transovarian transmission

A mode of transovum transmission in which the passage of microorganisms from mother to egg is known to occur through the ovary.

Transovum transmission

The transmission of microorganisms from one generation to the next by way of the egg.

Virion

The mature virus.

Virulence

The quality or property of being virulent. The disease producing power of the organism; i.e., the ability of the microorganism to invade and injure the tissues of its host. See pathogenicity.

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