Nocturnal activity and resource utilization in the aphid hyperparasitoid, Dendrocerus carpenteri

Abstract

Abstract. Females of the aphid hyperparasitoid Dendrocerus carpenteri (Curtis) search successfully for hosts during both day and night. Oviposition numbers per host patch did not differ significantly between day and night. D.carpenteri females also displayed a nocturnal flight activity, showing that they are not only capable of searching on a given host plant but also of dispersing between host plants. Nocturnal oviposition activity was mainly influenced by egg load. Females with a high egg load laid more eggs at night than females with a comparatively low egg load. Thus, D.carpenteri females may use nocturnal foraging to compensate for the lack of oviposition opportunities during day. D.carpenteri females which foraged continuously for hosts both day and night (= for 24 h per day) benefitted from an 1.4‐fold increase in lifetime reproductive success when compared to females which foraged only by day (= for 16 h per day). The benefit of night foraging for this species is a significantly increased reproductive success.