Performance of egg parasitoid Ooencyrtus pityocampae (Mercet) (Hymenoptera: Encyrtidae) on three substitute hosts in laboratory

Ooencyrtus pityocampae (Mercet) (Hymenoptera: Encyrtidae) is a solitary, thelytokous, synovigenic and polyphagous egg parasitoid which mainly attacks lepidopteran and hemipteran hosts. Releasing this parasitoid may be an appropriate way of decreasing insect pest populations. For this, it is first necessary to rear the parasitoid. Because of allergy risks and problems of life cycle and behavior, Thaumetopoea pityocampa, natural host of O. pityocampae, is not easy to rear so the use of a substitute host is essential. In this study, three substitute hosts were evaluated, Philosamia ricini (Danovan) (Lepidoptera: Saturniidae), Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) and Nezara viridula (Linnaeus) (Hemiptera: Pentatomidae). Experiments were conducted at 25±1°C, 65±5% RH, and a photoperiod of 16:8 h (L:D). Different biological characteristics of O. pityocampae were determined for each substitute host: the emergence rate, the development time, the parasitism rate, the longevity, the fecundity. Best emergence and parasitism rates and the highest fecundity were obtained on P. ricini eggs. However, the development time is longer on P. ricini. The shortest longevity is obtained on N. viridula eggs. Results show that P. ricini, N. viridula and H. halys can be used to rear O. pityocampae but P. ricini seems to be the best substitute host for this parasitoid rearing.