黑带食蚜蝇对茶蚜的捕食作用研究

Predation of Toxoptera aurantii by Episyrphus balteatus

为明确黑带食蚜蝇对茶蚜的捕食能力,研究了黑带食蚜蝇各龄幼虫对3~4龄茶蚜的捕食功能反应、寻找效应及整个幼虫阶段的日捕食量变化趋势。结果表明,黑带食蚜蝇各龄幼虫对3~4龄茶蚜的捕食功能均符合HollingⅡ型功能反应模型,其捕食能力随幼虫龄期的变大而增强,1~3龄幼虫的日最大捕食量分别为28.49头、93.46头和200.00头;随3~4龄茶蚜密度的上升,黑带食蚜蝇各龄幼虫的寻找效应逐渐下降,二者呈线性相关,相关系数为0.9842~0.9960,其中1龄幼虫寻找效应的下降趋势最大,3龄幼虫最小;黑带食蚜蝇幼虫对茶蚜的每日取食量随发育呈现先增加后减少的变化趋势,3龄幼虫总捕食量占整个幼虫总捕食量的73.5%,平均可取食410.9头茶蚜。试验结果可为黑带食蚜蝇应用于茶蚜生物防治提供依据。

To identify the predation capability of Episyrphus balteatus to Toxoptera aurantii,the predation functional responses,searching effect of E.balteatus at different developmental stages to the 3rd to 4th instars nymphs of T.aurantii,and the variation trend of daily predation amount of T.aurantii consumed by E.alteatus in the whole larval stage were explored.The results showed that the predatory functional response of E.alteatus at different developmental stages were fitted to Holling II equation.The predation capability of larvae increased with the age of larvae.The daily maximum predation amount of the 1st to 3rd instar larvae on T.aurantii were 28.49,93.46 and 200.00,respectively.The searching effect of instar larvae of E.alteatus decreased gradually with the increase of the density of the 3rd to 4th instar nymphs of T.aurantii.There was a linear correlation between the searching effect and the prey density,and the correlation coefficient was 0.9842~0.9960.The downward trend of the searching effect of the 1st instar larvae was the largest,and that of the 3rd instar larvae was the least.The daily predation amount of 3rd or 4th instars nymphs of T.aurantii consumed by E.alteatus showed a trend of first rising and then falling with the increase of ages.The total predation amount of the 3rd instar larvae accounted for 73.5%of the total predation amount of the whole larvae,and 410.9 T.aurantii could be fed on average.These results provide a basis for the application of E.alteatus in the biological control of T.aurantii.