双斑截尾寄蝇卵及幼虫发育过程及形态特征观察

Observation of egg age and larval developmental periods of Nemorilla maculosa

双斑截尾寄蝇(Nemorilla maculosa Meigen)为草地螟(Loxostege sticticalisL.)寄生蝇的优势种之一,是草地螟重要的寄生性天敌,本文首次报道了双斑截尾寄蝇卵期及幼虫期的各个虫龄的形态特征及发育过程。研究结果表明:双斑截尾寄蝇在以草地螟为寄主时的卵期约为4d,从卵孵化到离体化蛹的整个幼虫期可以分为3个虫龄,1龄虫期为1d左右,体色为白色,体长约为1.27mm;2龄虫期为4d左右,淡黄色,体长约为1.87mm;3龄虫期为2d左右,淡黄色,体长约为5.24mm。

Nemorilla maculosa Meigen （Diptera： Tachinidae） is among the important endoparasitoids of the beet webworm, Loxostege sticticalis L. （Lepidoptera： Pyralidae）. The egg age, the larval developmental periods and the larval characters of N. maculosa are firstly reported in this study. The egg age was about 4 days with L. stic- ticalis as the host. The whole larval age could be divided into 3 larval ages. The first larval stage was about 1 day, with white color and about 1.27 mm in length, the second larval stage was about 4 days, with primrose yellow color and about 1.87 mm in length; the third larval stage was about 2 days, with primrose yellow color and about 5.24 mm in length.