Annals of the Entomological Society of America (1996) 89, 667-675
Martha S. Hunter, Mike Rose and Andrew Polaszek (1996)
Divergent host relationships of males and females in the parasitoid Encarsia porteri (Hymenoptera: Aphelinidae)
Annals of the Entomological Society of America 89 (5), 667-675
Abstract: "Heterotrophic" parasitoids have been reported in the aphelinid genus Encarsia. These are species in which males develop as primary internal parasitoids of whitefly and males develop as primary internal parasitoids of lepidopteran eggs. The obligate nature of the host relationships in these aphelinids has been questioned and was investigated in this study. We examined the oviposition of female Encarsia porteri (Mercet) in 3 host types: bollworm eggs (Helicoverpa zea (Boddie)), sweetpotato whitefly nymphs (Bemisia tabaci (Gennadius)), and early pupal wasps (E. porteri). Although males of most Encarsia species develop on wasp pupae as hyperparasitoids, female E. porteri did not generally oviposit in wasp pupae. Whitefly nymphs were parasitized almost exclusively by mated females, whereas both mated and unmated females oviposited in moth eggs. The suitability of the above hosts as well as pupal E. formosa were also investigated for the development of male progeny. Males were produced only on moth eggs. Thus, we conclude that the heterotrophic host relationships of E. porteri are indeed obligate. Larval E. porteri are sexually dimorphic. Early instars of male larvae have a sculptured cuticle, bear long spines along the venter, and have horn-like projections on the head capsule. Females, in contrast, are more typically hymenopteriform with weak sclerotization of the head capsule, indistinct segmentation, and a smooth cuticle. Also, although both male and female early instar larvae are enclosed within a membrane, only females are enveloped by an opaque cellular layer within this membrane.
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Database assignments for author(s): Andrew Polaszek, Martha S. Hunter
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Helicoverpa zea | ||||
| Bemisia tabaci | ||||
| Encarsia porteri (parasitoid) | Helicoverpa zea | |||
| Encarsia porteri (parasitoid) | Bemisia tabaci |
