食虫齿爪盲蝽的生物学和捕食棉蚜效应研究

BIOLOGY OF DERAEOCORIS PUNCTULATUS FALLEN AND ITS ABILITY TO PREY COTTON APHIDS

本文系统地研究了蚜虫的重要天敌—食虫齿爪盲蝽的生物学和捕食棉蚜的效应。该虫在德州地区一年发生4代,有世代重叠现象,于10月下旬以成虫在杂草丛、苜蓿、土块下及枯枝落叶内越冬。平均单雌产卵61.67粒,卵散生于棉花和杂草的嫩茎、叶柄和叶片主脉内。若虫共5龄。雌虫产卵前期4.5～5.8天,卵期3.8～4.8天,若虫期11.2～13.3天。在6月中旬成虫和少量若虫迁入棉田完成第2代和第3代。在棉田内成,若虫出现盛期分别为6月下旬、7月上旬和8月初。测定其成虫和1～5龄若虫每天捕食棉蚜最大量分别为61.0、5.4,10.3,22.2、43.9和69.9头。

Deraeocoris punctulatus Fallen is an important natural enemy of aphids and somesmall insect pests.Observations show that it has four generations per year and a phenome-non of generation overlapping.It overwinters at the adult stage in weeds,alfalfa,soilblocks,whithered branches and fallen leaves in the third ten days of October in DezhouPrefecture of Shandong Province.The mean laying number of one female is 61.67 eggs scat-tered in tender stalks,petiols and main leaf veins of cotton plants and weeds.Its nymph hasfive instars in total.The preoviposition of a female lasts 4.5～5.8 days,the egg stage 3.8～4.8 days,and the nymph stage 11.2～13.3 days.In the cotton fields,this insectivorous bugmight accomplish two generations,and the population of adults and nymphs peaks in thethird ten days of June,the first ten days of July and at the beginning of August,respectively.According to calculation using Holling's disc equation(1959),an adult and anymph of 1～5 instar preys cotton aphids up to 61.0,5.4,10.3,22.2,43.9 and 69.9 heads aday,respectively.