Adult diet affects the life history and host-killing behavior of a host-feeding parasitoid

Abstract

Neochrysocharis formosa (Westwood), an important biocontrol agent of agromyzid leafminers worldwide, is a host-feeding, idiobiont parasitoid. Female wasps have three types of host-killing behaviors: reproductive (parasitism), non-reproductive host feeding (host feeding), and host stinging without oviposition or feeding (host stinging). In this study, we compared the life history and host-killing behaviors of female parasitoids under four adult diets: starvation, hosts only, hosts plus honey (10%w/v honey solution), and honey only. Furthermore, we analyzed the host-feeding and oviposition preferences of adult females in the hosts-only and hosts-plus-honey treatments. Female parasitoids feeding on hosts had significantly increased longevity, higher fecundity, more host-stinging events, and caused a higher total host mortality than parasitoids in the starvation treatment. The honey supplement significantly increased longevity, fecundity, host-stinging events, and total host mortality, as well as average daily fecundity, but did not alter host-feeding events, host-stinging events, or daily total host mortality. However, the honey supplement did reduce the number of daily host-feeding events and induced a shift toward oviposition. Finally, we found that the non-reproductive host killing caused by host feeding and host stinging enhanced the control potential of N. formosa. These results should contribute to a better understanding of the biocontrol efficiency of destructive host feeders.