Effects of Food Source Availability, Host Egg:Parasitoid Ratios, and Host Exposure Times on the Developmental Biology of Megacopta cribraria Egg Parasitoids

SIMPLE SUMMARY: This research investigated the reproductive characteristics of two egg parasitoids, Paratelenomus saccharalis and Ooencyrtus nezarae, which target Megacoptera cribraria eggs. We evaluated the impact of different food sources, host egg-to-adult parasitoid ratios, and host exposure times on the number and sex ratio of the parasitoid offspring. The findings showed that a honey solution was the preferred dietary source for O. nezarae. Furthermore, a 21:7 host-to-parasitoid ratio yielded the highest and predominantly female offspring for both parasitoids; a host exposure time of three to five days optimized parasitism by O. nezarae, whereas a one-day exposure time optimized parasitism by or P. saccharalis. These findings contribute to our understanding of the biology of both newly discovered egg parasitoids. ABSTRACT: Parasitoids forage for hosts in dynamic ecosystems and generally have a short period of time to access hosts. The current study examined the optimal reproductive attributes of two egg parasitoids, Paratelenomus saccharalis Dodd (Hymenoptera: Platygastridae) and Ooencyrtus nezarae Ishii (Hymenoptera: Encyrtidae), of the kudzu bug, Megacopta cribraria Fabricius (Hemiptera: Plataspidae). The proportion of O. nezarae and P. saccharalis adult offspring that emerged from M. cribraria eggs and the sex ratio of the parasitoid offspring were compared among treatments for the effects of different adult parasitoid food sources, host egg-to-adult parasitoid ratios, and host exposure times. Our results suggest that honey solution as a food source, a 21:7 host-to-parasitoid ratio, and three-to-five days of exposure time optimized the production of female O. nezarae offspring. For P. saccharalis, honey solution as a food source, a 21:7 host-to-parasitoid ratio, and one day were optimal for maximizing female offspring production. These findings provide new information about the biology of these egg parasitoids.