丹巴腮扁叶蜂生物学特性及为害调查

BIONOMICS AND INFESTATION OF WEB-SPINNING SAWFLY CEPHALICA DANBAICA IN QINGHAI PROVINCE

丹巴腮扁叶蜂(Cephalcia danbaica Xiao),自1987年由肖刚柔教授根据采自四川丹巴(桑地)的标本,定为新蜂种以来,迄今未见有关其生物学和为害的报道。近年来,该虫在青海部分林区为害相当严重,现将其发生情况记述如下。一、生物学特性 (一)寄主主要为害青海云杉(Picea crassifolia Kom.)亦加害华北落叶松(Larixprincipis-rupprechtii Mayr) (二)分布国内发生于四川(丹巴)、甘肃(武威),青海(大通),互助,湟中。大通县东峡林区是丹巴腮扁叶蜂的严重发生地,境内多青海云杉的片状纯林,海拔为2600-2800m。 (三)生活周期和主要习性 1.成虫发生期观察方法是在奇数年份,选择受害的云杉树,在其下用尼龙纱围绕基干扎成裙网,共计5个。在成虫出现前,每日检查一次,捉净网中当日羽化的成虫。这样直至羽化结束。据1989年定位观察,共查得成虫747头,其中雄蜂226头,雌蜂521头;

The web-spinning sawfly Cephalica danbaica Xiao is an important insectpest of Picea crassifolia Kom,and causes severe infestation in the eastern partof Qinghai Province. It was obsevered that the sawfly took 2 years tocomplete its life cycle which may extend to the third year after infestation. Dueto the succession only with a single year-group, it rests in the soil duringthe year of even number and infests on the trees during the year of oddnumber. The adults and eggs presented in mid June to early July. The firstinstar larvae occurred in July. The mature larvae leave away from the treesin early August to mid September, and dig into the soil where it remainsinactive about 21 months within the earthen cell. The larval stage consistsof 6 instars. In the forest which is infested seriously,the use of insecticidalsmokes to kill the pest on the trees is effective. To the trees of sporadicinfested with the larvae cutting away the larval rests is also effective.