The influence of diet and temperature onNabis roseipennisReuter feeding, development, longevity, and fecundity was investigated in the laboratory. Temperatures of 20, 25, and 30° C did not influence total consumption ofHeliothis virescens(F.) first stage larvae but did influence consumption ofLygus lineolaris(Palisot de Beauvois) first and second stage nymphs. Predation onLygusnymphs decreased at the higher temperatures. Predator nymphs consumed moreH. virescenslarvae thanL. lineolarisnymphs in developing to adulthood. Developmental times were generally independent of the prey food source. The mean consumption of prey and the mean duration of the developmental period for predator nymphs increased with each successive nymphal stage at all temperatures. The predator survived longer at 20 and 25°C than at 30°C on both prey food sources. Oviposition was not influenced by diet but was influenced by temperature. More eggs were laid at 25°C than at 20 or 30°C.