梨卷叶瘿蚊的研究

近几年,浙江省很多地方危害梨树的梨卷叶瘿蚊大发生。幼虫取食叶汁液形成虫瘿。本文报道了此虫卵、幼虫、蛹、成虫的形态特征、生物学和生态学特性。梨卷叶瘿蚊在浙江临安la发生2～3代。以老熟幼虫在表土层中越冬。卵产在未展开或刚展开的叶芽上。由于幼虫的取食导致叶的两个边缘沿中脉向内卷褶,使1片叶子形成两个虫瘿。每个虫瘿里有20～50条幼虫。由于幼虫的危害,使梨刚抽出的叶芽嫩枝枯死。用40％氧化乐果1000,1500倍液或用25％菊乐合酯、50％甲胺磷1000倍液喷杀初龄幼虫,可收到较好的防治效果。

Study on Pear Leaf Gall-midge

In recent years, severe outbreak of Dasyneura pyri Bouche has occurred on pear tree in various parts of Zhejiang Province. The cecidomyiia develops on the leaves on which galls are caused by larval feeding. The morphology of egg, larva, pupa and adult of the cecidomyiia are described, and observations on its bionomics are recorded in the present paper. There are two or three generations a year in Lin'an County. It overwinters as full grown larva in the surface layer of the soil. Eggs are laid on the unopened leaf buds or the newly expanded leaves of the tree, and larva feeding results in the edges of the leaves curling along the apex inwards and becoming two galls. Up to 50 larvae are noted in a single gall, injury always withers up the pear sprouts. Effective control may be achieved by spraying with omethoate or methamidophos, and decamethrin + dimetheate as well against the early larval stage.