The influence of the parasitoid Hexacladia smithii Ashmead (Hymenoptera: Encyrtidae) on the feeding activity and on survival of the neotropical brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), was evaluated in laboratory, at 10, 20, 30 and 40 days after parasitism. The feeding activity was evaluated through the number of stylet sheaths deposited on soybean seeds, Glycine max (L.) Merrill (Fabaceae), after feeding for 48 hours. The tests were conducted under controlled conditions of temperature (25±2°C), RH (65±10%) and photoperiod (14L:10D). At the beginning of the development of H. smithii the feeding activity of non-parasitized and parasitized bugs was similar; however, the number of stylet sheaths was two times greater in seeds fed upon by parasitized stink bugs than those fed upon by non-parasitized bugs, for males and females 30 days after parasitism. The survival of parasitized adults was smaller than that of non-parasitized adults, reaching 100% of the bugs died after 40 and 50 days of parasitism. The reduction in the survival of the stink bugs parasitized by H. smithii and the similar feeding activity among parasitized and non- parasitized bugs during almost the whole period of development of the parasitoids, put in relief the contribution of that parasitism to the reduction of the population of neotropical brown stink bug E. heros.
Glycine max; biological control; neotropical brown stink bug; parasitoid; stylet sheath
