Abstract Stink bugs (Hemiptera: Pentatomidae) are among the most economically important pests of soybean, Glycine max (L.) Merrill, in Missouri, where management relies largely on broad-spectrum insecticides. Despite evidence that parasitoids contribute to stink bug suppression in other regions, information on parasitism in Missouri soybeans remains limited. We conducted a 2-yr survey (2024 to 2025) in 316 soybean fields in Missouri to quantify parasitism of adult stink bugs by tachinid flies (Diptera: Tachinidae). In addition, stink bug egg masses were sampled for the presence of egg parasitoids once in 152 soybean fields across the state, and weekly at three locations during the 2025 growing season. Overall, 7.4% of adult stink bugs were parasitized, with higher parasitism observed in males than in females; adult parasitism also varied significantly between years, with 10.4% in 2024 and 6.5% in 2025. Egg parasitism was detected in 9.4% of egg masses and 4.1% of individual eggs collected statewide. Season-long monitoring showed significant differences among locations. Parasitism differed among stink bug species, with eggs of the Brown complex (Euschistus spp.) exhibiting significantly higher parasitism rates than those of Chinavia hilaris (Say) (Hemiptera: Pentatomidae). The egg parasitoids Trissolcus edessae Fouts (Hymenoptera: Scelionidae) and Telenomus podisi Ashmead (Hymenoptera: Scelionidae) were found parasitizing stink bug eggs. Together, these results provide the first comprehensive assessment of stink bug parasitism in Missouri soybeans and establish a baseline for evaluating parasitoids’ contribution to suppressing stink bug populations.
Bosetti et al. (Tue,) studied this question.