Important Terms used in Biological Control of Crop Pests – VI
1. Parasite:
An animal species which level on or in a larger animal, the host, feeding upon it, and frequently destroying it. A parasite needs only one or part of one host to reach maturity.
2. Parasitism:
A qualitative term referring to a kind of symbiosis in which one party (the parasite) lives at the expense of the other (the host), contributing nothing to the relationships and frequently destroying the host in the process.
3. Parasitization:
A quantitative term referring to the proportion of a host population attacked by parasites.
4. Parasitoid:
An insect parasite of an arthropod parasitic only in its immature stages, destroying its host in the process of development and free living as an adult.
5. Periodic release:
A method of beneficial organism introduction which involves repeated liberations to artificially maintain high population levels of indigenous biotic agents in situations which such levels are unattainable naturally.
6. Polyhedrosis:
An insect viral disease characterized by formation of polyhedron shaped inclusions in the infected calls. The disease is known as a nuclear Polyhedrosis or nucleopolyhedrosis.
7. Polyphagous:
Adapted to the use of wide variety of plant or animal species as hosts or prey.
8. Population Dynamics:
The study of numerical changes in populations of living organisms in time and space and of the processes which cause such variations.
9. Predator:
An animal which feeds upon other animals (prey) that are usually smaller and weaker than itself, frequently devouring them completely and rapidly. A predator most often is required to seek out and attack more than one prey to reach maturity.
10. Primary Parasitoid:
An insect parasite of any arthropod which is not itself parasitic.
11. Protelean Parasite:
An insect species in which only the immature stages are parasitic.
12. Secondary Parasitoid:
An insect species of a primary parasitoid.
13. Septicemia:
A morbid condition caused by invasion and multiplication of microorganisms in the blood.
14. Solitary Parasitism:
All insect parasite which normally develops at a rate of one individual per arthropod host.
15. Superparasitism:
A condition resulting from the use of a single host individual by more individual parasitoids of the same species than it can successfully sustain to maturity because of nutritional limitations.
16. Symbiosis:
The living together in close association of two or more species of organisms.
17. Thelyotoky:
A type of parthenogenetic reproduction in which only female progeny are produced.
18. Tolerance:
According to Painter (1951), it is the basis for resistance in which a host shows an ability to grow and reproduce itself, or to repair injury, despite supporting a pest population equal to that damaging a more susceptible host.
19. Trap Crop:
A small planting of a susceptible and highly attractive host, planted early in the season, or removed in space from the main crop, in order to divert attack and infestation by pests and allow for their easy destruction.
20. Virulence:
The disease producing power of a microorganism, i.e. the relative capacity of a microorganism to invade and injury the tissues of its host.