The effect of prey quality on diapause of the predator Geocoris punctipes (Heteroptera: Geocoridae) was evaluated in the fall and winter in field cages. Two prey types were used: 1) eggs of the corn earworm (CEW), Helicoverpa zea, as high-quality prey, and 2) first-instar larvae of the beet armyworm (BAW), Spodoptera exigua, as low-quality prey. Predators were reared outdoors in the autumn on the two prey types and subsamples of predators were transferred to the laboratory in November and December to assess diapause intensity and diapause development. The remainder of the bugs were left outside throughout the winter and their survival and reproduction were monitored. Prey quality tended to enhance diapause intensity early in the fall, but there no differences by mid-winter. Predator reproduction was significantly greater for those fed CEW eggs than those fed BAW larvae, but overwintering survival was not significantly affected.