Performance ofGeocoris punctipes(Say) nymphs was studied on the pest-resistant soybean,Glycine max(L.) Merrill, genotypes PI 171451 and PI 229358, and pest-susceptible ‘Bragg’ and ‘Govan’.G. punctipesnymphal growth rate decreased when the insect food was velvetbean caterpillar (VBC),Anticarsia gemmatalisHübner, reared on ‘Bragg’, PI 229358, or PI 171451. Mortality of nymphs increased when they fed on PI 171451- or PI 229358-reared VBC larvae. Direct effects of plant food as detached leaflets included increased nymphal development time and increased nymphal mortality. Development time of nymphs was increased on a diet that included PI 171451 leaf and PI 171451- reared soybean looper,Pseudoplusia includens(Walker)