Effects of host life stage and female wasp’s age on parasitizing behaviors and offspring developmental consequences in Aenasius arizonensis (Hymenoptera: Encyrtidae)

Author of the article:Lü Yu-Jia1 GUO Xiao-Meng2 QIN Wen-Quan1 MENG Ling1 LI Bao-Ping1

Author's Workplace：1. School of Plant Protection, Nanjing Agricultural University; 2. Institute of Hilly Land Agriculture of Zhenjiang City, Jiangsu Province

Key Words：Phenacoccus solenopsis; classical biological control; parasitoid natural enemy; invasive insects; age; host quality

Abstract：[Aim]  This study aims to determine how female wasp’s age influences oviposition-related behaviors and offspring developmental consequences of the parasitoid Aenasius arizonensis, a biocontrol agent attacking different life stages of the invasive cotton mealybug Phenacoccus solenopsis. [Methods]  The 3rd instar nymph and neonatal female adult of the mealybug were exposed to parasitism by A. arizonensis females every day across their lifetime. Female’s examination/ oviposition behaviors and offspring body size at eclosion were measured and analyzed in relation to female age and host life stage at parasitism. [Results]  Aenasius arizonensis females exercised a longer time for both antennal tapping and ovipositor-drilling on female adult mealybugs than on 3rd instarnymphs, but these behaviors were not affected by female wasp’s age. Female wasps conducted more frequent drilling with the ovipositor on the female adult mealybug than on the 3rd instar nymph and markedly decreased the drilling frequency over female’s age. Body size of offspring adults was larger from attacking the adult mealybug than attacking the 3rd instar nymph but did not vary with female’s age. [Conclusion]  Female wasp’s age only influences host-examining behaviors while host life stage has an effect on both host-examining behaviors and offspring developmental outcome.