An Evaluation of Damage to Soybeans by Brown and Green Stink Bugs1

Cages each containing from I to 4 pairs of brown stink bugs, Euschistus servus (Say), infesting 6 soybean plants were used to evaluate feeding damage. As the rate of infestation increased, the number of undeveloped beans produced in the middle third of the plant increased. A significant difference between the numbers of undeveloped beans in damaged and undamaged soybean pods was noted. Damaged beans were significantly smaller than undamaged beans. Oil content of damaged beans was an average of 7.0% less than that in undamaged beans. Oil content decreased and protein content increased as damage increased. Germination was reduced in proportion to the number of stink bug punctures per bean. Additional tests were conducted with the green stink bug, Acrosternum hilare (Say), as the principal pest feeding on 5 varieties of soybeans planted on 4 different dates. The longer the period from bloom to maturation for a given variety the more severe the feeding damage became.