Growth characteristics of the sexual generation of Schlechtendalia chinensis

Author of the article:SHAO Shu-Xia, YANG Zi-Xiang, YAN Gao-Hong, CHEN Hang, XU Xin, WEI Hong-Yuan

Author's Workplace：Institute of Highland Forest Science, Chinese Academy of Forestry, Key Laboratory of Breeding and Utilization of Resource Insects, National Forestry and Grassland Administration, Kunming 650224, China

Key Words：Schlechtendalia chinensis (Bell); sexuale; morphological development; weight; humidity

Abstract：[Objectives]  To clarify the morphology and growth characteristics of the sexual generation of Schlechtendalia chinensis (Bell) and thereby improve artificial gallnut cultivation technology and yield. [Methods]  Sexual S. chinensis were reared on concave microscope slides and molt, changes in body color, body length and width, observed using an inverted fluorescence microscope. A microelectronic balance was used to measure aphids’ fresh and dry weight and thereby calculate their water content. Newborn aphids were placed in dark, artificial climate boxes at 24 ℃, at a humidity of either 30%, 50%, 70% and 90% and the number of deaths per day was recorded and compared. [Results]  The mouthparts of sexual aphids are degenerate. Females and males began to molt on the day of birth, molting 4 and 3 times within their lifetime, respectively. Body length and width both showed negative growth trends. Mating occurred 5-8 days after birth. Females survived for 25 days and males for up to 15 days. Females’ dry weight increased twice during their lifespan; on the 3rd to 5th day and on the 11th to17th day after birth. Males’ dry weight consistently decreased. The water content of females and males both increased, the latter was higher than the former. The correct environmental humidity was crucial for growth and development; 70% humidity was optimal, higher or lower humidity was not conducive to normal growth and development. [Conclusion]  Although the sexual generation S. chinensis cannot eat, they complete normal life activities such as molting, mating and reproduction. Furthermore, their water content and female dry weight increase over their lifetime.