Biology of the ectoparasitoid Bracon hebetor Say, 1857 (Hymenoptera: Braconidae) on seven lepidopteran species

Abstract

Bracon hebetor Say, 1857 is a larval ectoparasitoid of several species of pyralids which attack stored grains, therefore a potential biological control agent of these pests. To determine the best host for laboratory rearing, the biology of B. hebetor was studied under controlled temperature conditions (25 ± 2°C), relative humidity (60 ± 10%) and photoperiod (14-hour photophase) on seven lepidopteran larvae: natural hosts Anagasta kuehniella (Zeller), Corcyra cephalonica Stainton and Sitotroga cerealella (Olivier) and in the insects regularly reared at the Insect Biology laboratory of ESALQ/USP, Diatraea saccharalis (Fabricius), Heliothis virescens (Fabricius), Anticarsia gemmatalis Hübner, and Spodoptera frugiperda (J.E. Smith). Duration and viability of the biological cycle (egg-adult) were affected according to the host used. A. kuehniella and C. cephalonica were similar hosts for B. hebetor rearing, producing insects with life cycle of 12.8 days, viability around 90% and excellent paralyzing and parasitism capacities. D. saccharalis was the only not-natural host providing similar results to those found on the three-grain stored moths. Regarding aggressiveness, D. saccharalis produced insects with paralyzing and parasitism capacities similar to those reared on S. cerealella and C. cephalonica.