夹竹桃天蛾的生物学特性

Bionomics of the oleander hawkmoth,Daphnis nerii

夹竹桃天蛾Daphnis nerii(Linnaeus)是夹竹桃上的重要害虫,具有间歇性爆发的特点。该虫在湖南省衡阳地区1年发生2～3代,以蛹在寄主附近的枯枝落叶层、表层松土及土壤缝穴中越冬。越冬代成虫于6月上旬出现,6月中下旬产卵。6月下旬第1代幼虫孵化;第1代成虫于7月中旬出现,7月下旬产卵。第2代幼虫8月上旬孵化,8月下旬至9月上旬幼虫危害最历害,9月中旬开始化蛹,化蛹持续到10月中旬。第2代蛹发生分化,一部分成为越冬蛹,另一部分则羽化为成虫。第2代成虫于10月上旬开始产下第3代卵。10月上旬第3代幼虫开始孵化,11月中旬第3代幼虫开始化蛹、越冬。

The oleander hawkmoth,Daphnis nerii（Linnaeus） is a serious pest of the garden plant,Nerium indicum Mill.D.nerii has two or three generations per year in the Hengyang area,Hunan Province,overwintering as pupae under the layer of the dead branches and fallen leaves,in loose topsoil and in cracks and holes in the earth near the host plant.The adults of the over-wintering generation emerge in the first ten days of June and oviposit between the middle and last ten days of June.The first generation larvae hatch in the last ten days of June and the first generation adults emerge in Mid-July and oviposit in the last ten days of July.The second generation larvae hatch in the first ten days of August.Plant damage is most severe from the last ten days of August to the first ten days of September.Larvae begin to pupate in mid-September,pupation continuing until mid-October.The second generation pupae differentiate into two groups,one of which becomes over-wintering pupae,and the other becomes second generation adults which lay the third generation eggs.The third generation larvae hatch in the first ten days of October and over-winter as pupae from mid-November.