Biological characteristics of Scolothrips takahashii Prisener, a natural enemy of mites
Author of the article:ZHANG Jin-Yong** TU Hong-Tao WU Zhao-Jun LI Qiao-Shuang CHEN Han-Jie***
Author's Workplace:Zhengzhou Fruit Research Institute, Chinese Academy of Agricultural Sciences, Zhengzhou 450009, China
Key Words:Scolothrips takahashii, Tetranychus urticae, biology, temperature
Abstract:
[Objectives] To investigate the biological parameters of the six spotted thrip Scolothrips takahashii Prisener at different temperatures, and the effect of temperature on female fecundity. [Methods] The biological characteristics of the six spotted thrip, fed on the eggs of the two-spotted spider mite, were observed at 18, 22, 26, 30, and 34℃, respectively. [Results] The developmental duration of one generation at 18℃ was about one month compared to about 7.8 d at 34℃。The developmental zero and effective accumulated temperatures were 12.4℃ and 171.0 degree days, respectively. The number of mite eggs preyed on by adult six spotted thrips increased with temperature from 18℃ to 34℃. A single female six spotted thrip could consume about 105 mite eggs, however, the number of mite eggs preyed on by thrip larvae was not much affected by temperature. The sex ratio of the six spotted thrip decreased with increasing temperature. [Conclusion] It seems that the six spotted thrip is an insect suited to a high temperature environment. This may explain why six spotted thrip numbers are relatively low in spring but increase suddenly after June making them the dominant natural enemy of mites.