Stink Bug (Hemiptera: Pentatomidae) Egg Parasitism in Louisiana Soybeans

Stink bug egg parasitism rates were surveyed at several locations in southern Louisiana during 1983 and 1984. Eggs of Euschistus spp. were parasitized most heavily. Parasitism of eggs of Nezara viridula (L.), Euschistus spp., Acrosternum hilare (Say), Podisus maculiventris (Say), and Edessa bifida (Say) varied between sample years. All parasitoid species collected were in the family Scelionidae. Telenomus podisi Ashmead was the most prevalent parasitoid during both 1983 and 1984. Parasitism by Trissolcus basalis Wollaston was high in 1983 but declined sharply the following year when populations of its primary host, N. viridula, were low. Apparent host switching was noted for both T. podisi and T. basalis from their primary hosts Euschistus spp. and N. viridula, respectively, when densities of all host masses increased. Trissolcus edessae Fouts and Trissolcus euschisti Fouts were collected both years at levels substantially below those of T. podisi and T. basalis. Telenomus calvus Johnson, a phoretic egg parasitoid of P. maculiventris, and Telenomus cristatus Johnson were collected incidentally during 1983. Parasitism of single egg masses by two different scelionid species was observed in all pentatomid hosts except E. bifida. In every case except one, both a Trissolcus species and T. podisi were involved. In the lone exception, both species were in the genus Trissolcus. Multiparasitism of individual eggs was not observed in this study.