桑树上桑蓟马的分布规律及天敌的调查

Distribution of Mulberry Thrips on Branches and its Investigation of the Natural Enemies

根据对桑树上桑蓟马虫口密度的调查,明确其分布主要集中在桑枝3 ～10 叶位上,最高虫叶位随桑树的树势强弱而变化。桑蓟马虫口数量受气候变化的影响较大,高温干旱期,桑蓟马虫口数量猛增,桑树受害最重;风雨有碍桑蓟马的发生,每次可减少桑蓟马21% ～88 % 。通过田间调查,桑蓟马的主要天敌有:大草蛉、中华草岭、横纹蓟马及一些瓢虫和小蜘蛛等。

Investigation showed that mulberry thrips were mainly concentrated on a branch section from the 3rd to the 10th leaf. The more vigorous a mulberry tree, the closer the thrips were distributed towards the branch top. Climate had a significant effect on the population of the thrips. During a hot and dry period, the thrips population increased sharply, causing a heavy damage. Wind and rain could decrease the thrips by 21% to 88%. It was found in the field survey that the natural enemies of mulberry thrips were mainly of Chrysopa septempunctata, C. sinica, Aeolothrips fasciatus, lady beetles and some small spiders.