Maternal effect of diapause in Aphidius gifuensis Ashmead
Author of the article:ZHANG Li-Sheng** , CHEN Hong-Yin , ZHANG Jie, LI Yu-Yan
Author's Workplace：Laboratory of Integrated Pest Management in crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences; Sino-American Biological Control Laboratory, USDA-ARS, Beijing, 100081, China
Key Words：Aphidius gifuensis, diapause, maternal effect
Abstract： [Objectives] Aphidius gifuensis Ashmead is an important solitary endoparasitoid of aphids and is a significant biological control agent for these pests. Research on diapause in A. gifuensis can not only help us better understand the development of this beneficial insect, but could also enhance the efficiency of using it as a bio-control agent. Previous studies have suggested that low temperature and short-days can induce this parasitic wasp to enter diapause, thereby extending its “shelf-life” for up to 120 days. [Methods] In this paper, we analyzed the F1 and F2 generation’s emergence rate, sex ratio, adult longevity, diapause rate and other biological indicators. [Results] Parental diapause had a significant effect on the biological characteristics of the F1 and F2 generations. The number of female parasitoids and the diapause rate of the F1 generation increased significantly; the proportion of females in the F1 generation increased from 0.59 to 0.65 after diapause had been maintained for 30 d. There was no significant difference in the number of female parasitoids between the F2 generation and the control; the proportion of females among post-diapause and non-diapause A. gifuensis offspring was around 0.58. There was a significant increase in the diapause rate of the F1 generation offspring, increasing from 44.75% to 74.01%. The parasitic capacity of F1 females increased slightly, but not significantly, compared to the control. The emergence rate of post-diapause and non-diapause A. gifuensis offspring was > 88% at 20℃and25℃, L16: D8, RH 75%, 4 400 lx and the average longevity of different diapause duration A. gifuensis offspring was > 6.0 days. [Conclusion] There is a significant maternal diapause effect in A. gifuensis, parental diapause can significantly improve the diapause rate of the first generation, which will help it to withstand adverse environmental stress and thereby improve its survival.