芋双线天蛾的生物学特性

Biological Characteristics of Theretra oldenlandiae(Fabricius)

芋双线天蛾[Theretra oldenlandiae(Fabricius)]在河口地区一年发生4代,以蛹在寄主附近土壤中越冬。第4代(越冬代)成虫最早见于5月中旬,持续到11月初。7~9月为该虫害高发期。该虫幼虫发育分为5个龄级,4、5龄级生长快,食量大,是虫害的主要危害期;其发育历期与温度有关,第1代历期最长,平均为42.7 d,第2代最短,平均为29.4 d。

Theretra oldenlandiae（Fabricius） had four generations a year in Hekou, and lived through winter as pupa in the soil nearby the host plant. The adults of the fourth generation（over-wintering generation） emerged the earliest in mid May until early November. Peak infestations occurred from July to September. The larval development could be divided into 5 instars, and the fourth and fifth instar larvae grew fast with large appetite and were the main stage for infestation. The developmental duration of this pest was related to the temperature. The first generation time for this pest was the longest, about 42.7 days by average, and the second generation time was the shortest, about 29.4 days.