白跗平腹小蜂林间动态研究

Population Dynamics of Anastatus olbitarsis in Masson Pine Forest.

白跗平腹小蜂在浙江于４月中下旬自然羽化，１０月上旬在第３代马尾松毛虫卵中，１１月在柳杉毛虫卵中，以老熟幼虫越冬，翌年４月中下旬开始羽化活动。在自然温度下，用柞蚕剖腹卵繁殖，年发生６～７世代。在林间的年周期活动中，其种群数量分别在５～６月和９～１０月出现两次高峰。这和马尾松毛虫、柳杉毛虫、水青蛾、大背天蛾和油茶枯叶蛾等主要森林害虫的卵期吻合。该蜂对它们的抑制力分别是１６．５５％～２２．９０％’２３．４５％，２．６３％～５．４９％，１．９７％和３．００％～７．００％。该蜂在林间的水平扩散距离达３２ｍ以上。

Anastatus albitarsis naturally incubates in the middle and late Anril in Zhe jiang Province,Its mature larvae overwiter in eggs of the third gene-ration Dendrolimus puntatus in early October, in eggs of Dendrolimus latipenuis in November, Under natural temperature,there are 6～7 generations each year,There are two peaks of population which occur from May to June and from September to October respectively . The peak time coincides with the egg seaoon of main forest insects such as Dendrolimus punctatus,Dendrolimus latipenuis, Actias seleneningpoana,Meganbton analis and Lebeda nobilis,and its con-troling rate to above insects are 16.55%～22.9%, 23.45%,2.63%～5.40%,19.50%and 3.00%～7.00%respectlvely,The wasp can spread more than 32 meters of level distance in the forest.