ENTOMOLOGY 135 Parasitoids: Classification and Terminology

ENTOMOLOGY 135

INTRODUCTION TO BIOLOGICAL CONTROL

Parasite.
1. Webster.--An organism living in or on another organism.
2. Biological control.--A species whose larva develops at the expense of one host individual.
Parasitoid.--A parasite which kills its host; generally used interchangeably with "parasite" in biological control.
Protelean.--Insects in which only the larval stage is parasitic.
Predator.--A species whose immature form (nymph or larva) develops at the expense of more than one host individual (in context of biological control).
Facultative.--Species whose larva can develop either as a parasite or a predator, depending on conditions (rare in nature).

Primary.--A parasite of a non parasitic host.
Hyperparasite.--A parasite of a parasitic host.
1. Secondary.--A parasite of a primary parasite.
2. Tertiary.--A parasite of a secondary parasite.
Facultative.--A species which can develop either as a primary or a hyperparasite.

Egg away from the host.
1. Microtype egg eaten by host, larva develops as endoparasite.
2. Plannidium larva, hypermetamorphosis, larva develops as endoparasite.
Egg on or near host.
1. Larva develops as ectoparasite.
2. Larva penetrates host and develops as endoparasite.
Egg inside host, larva develops as endoparasite.

Monembryonic.--One embryo gives rise to one individual.
1. Solitary.--One parasite individual develops at the expense of one host.
2. Gregarious.--Two or more individuals (from different embryos) of same species develop at the expense of one host.
3. Facultative.--Either solitary or gregarious, depending on the size of the host.
Polyembryonic.--One embryo divides mitotically, producing many genetically identical individuals which develop at the expense of one host.

Egg.--Complete life cycle of parasite in host egg.
Egg-larval.--Parasite egg placed in host egg, parasite larva develops in and kills host larva.
Larval (Nymphal).--Complete life cycle of parasite in (or on) host larva (or nymph).
Larval-pupal.--Parasite egg placed in host larva, parasite larva completes development in and kills host pupa.
Larval-adult.--Parasite egg placed in host larva, parasite larva completes development in and kills host adult (rare in nature).
Pupal.--Complete life cycle of parasite in or on host pupa.
Pupal-adult.--Parasite egg in host pupa, parasite larva completes development in and kills host adult (rare in nature).
Adult.--Complete life cycle of parasite in adult of host species.

Host specific.--Parasite is generally restricted to one host species under natural conditions (cf. monophagous); in contrast to a generalist, which can successfully complete development in many host species (latter are usually taxonomically related).
Stenophagous.--Parasite with a narrow host range (cf. oligophagous); in contrast to euryphagous which denotes wide host range (cf. polyphagous).

Thelyotoky.--Diploid females give rise to diploid females; no males exist.
Deuterotoky.--A form of thelyotoky in which a few (non-functional?) males are produced.
Arrhenotoky.--Males are haploid and develop from unfertilized eggs whereas females (diploid) develop from fertilized eggs (synonyms: facultative parthenogenesis, haplodiploidy, male-haploid system).
Adelphoparasitism.--Special form of arrhenotoky in which haploid males develop as hyperparasites, often on diploid females of the same species.

Variable fitness.--Males develop in smaller hosts and females develop in larger ones. Larger females from larger hosts live longer and lay more eggs.
Local-mate competition (LMC).--Female-biased sex ratio in inbreeding species where sons of same female compete for mates; expect female to allocate the minimum number of males necessary to inseminate all females that develop in discrete host patch (e.g., quasi-gregarious egg parasites, gregarious larval parasites).

Pro-ovigenic.--Female emerges with full complement of ripe eggs; no additional eggs produced.
Synovigenic.--Ovigenesis occurs during adulthood.
1. Linear.--Ovigenesis, ovulation, oviposition.
2. Cyclic.--Eggs may be absorbed (ovisorption) when hosts are unavailable.

Koinobiont.--A species which allows the host to continue to develop, move about, and defend itself; as opposed to an idiobiont which halts host activity before the parasite's egg hatches.
Regulator.--A species which interferes with or alters the host's biochemical processes; as opposed to a conformer in which the egg or newly hatched larva remains inactive while allowing the host to develop and then are triggered by host conditions to begin their own development.
Pseudoparasitism.--Oviposition (or penetration with the ovipositor) without the production of offspring.

Superparasitization.--Too many individuals of the same species of parasite in one host individual; only one individual (sometimes none) usually survives.
1. Self superparasitization.--Involving progeny of the same female.
2. Conspecific.--Involving progeny of different females.
Multiple parasitization.--Too many individuals involving different species of parasites in one host†individual; survival as in 11.a (synonyms: heterospecific or interspecific superparasitization).
Cleptoparasitization.--Primary parasite preferentially parasitizes a host already parasitized by†another species (i.e., obligate multiple parasitization).

Direct.--Female searches for and oviposits in or on the primary parasite; in contrast to indirect in†which the female searches for and oviposits in or on the nonparasitic host. These should be viewed†as two points on a continuum.
Obligate.--A species whose larva can develop only as a hyperparasite (cf. facultative, item 2.3).

Density dependent.--Percent parasitization varies with host density; can be either direct (positive)†or inverse (negative) and can be measured either spatially or temporally (cf. density independence).
Species dependent.--Total percent parasitization varies with number of parasite species exploiting†the host; can be direct or indirect and can be measured spatially or temporally (cf. species independence).