日光蜂对苹果绵蚜的自然控制作用及其保护和利用

Natural control of Aphelinus mali on Eriosoma lanigerum and the parasitoid’s overwintering protection measures

日光蜂是苹果绵蚜的一种重要寄生性天敌,为了更好地发挥其对苹果绵蚜的控制作用,在山东省莱阳市田间调查研究了日光蜂对苹果绵蚜的自然控制作用,并测定了不同保护措施下日光蜂的越冬羽化率。结果显示,苹果绵蚜在5月底至7月底和9月中旬至10月中旬有2个发生高峰;在整个生长季节日光蜂对苹果绵蚜均有一定的控制作用,7月上旬至9月上旬温度较高时,日光蜂的田间种群数量较多,对苹果绵蚜的田间自然寄生作用达到高峰,寄生率在50%～90%,4—5月是日光蜂对苹果绵蚜的控制空缺时期。在使用化学农药的果园,日光蜂的数量和寄生率均降低。田间缚草或采集日光蜂黑蛹放置于室内或室外阳面,越冬存活率均显著高于放置在室外阴面和田间未缚草的日光蜂黑蛹,表明3种越冬保护措施可以有效地增加日光蜂越冬虫源基数。

Aphelinus mali （Haldeman） is an important parasitoid of Eriosoma lanigerum （Hausmann）. The natural control effect of A. mali on E. lanigerum in apple orchards in Laiyang, Shandong Province and overwintering eclosion rate of A. mall under different protective measures were studied. The results showed that two peaks of E. lanigerum occurred from late May to late July and from mid September to mid October. The parasitoid could control E. lanigerum to some extent in the whole year. Its natural parasit- ism rate reached the peak up to 50% -90% from early July to early September, while the control vacan- cy appeared in the period from April to May. In the chemically controlled apple orchard, the number and parasitism rate of A. mall decreased because of chemical pesticides. Overwlntering eclosion rate was higher when some protective measures were taken, e.g. attaching grass around trunks or depositing the black ＂pupa 99 parasitized by A. mali indoors or on south slope of open field. This could increase the number of alive parasitoids after overwintering, thus enhance its control efficiency on E. lanigerum.