花绒坚甲对光肩星天牛的寄生效果研究

为了确定自然状态下花绒坚甲对光肩星天牛的寄生规律,为利用花绒坚甲控制光肩星天牛提供依据,试验采用解析木调查法和统计分析法,于不同月份解析光肩星天牛危害的杨树树干,研究了光肩星天牛及其天敌花绒坚甲的数量变化规律,以及花绒坚甲对光肩星天牛的控制效果。结果表明,花绒坚甲在4至7月中旬的第一姊妹世代,对天牛大幼虫的寄生率增长趋势较慢;在7月下旬至9月下旬由第二姊妹世代与当年第二代组成的混合世代,其寄生率增长趋势较快;当被害立木蛀道数达30~45条时,蛀道内花绒坚甲的种群数量最大;光肩星天牛蛀道内花绒坚甲的种群密度随天牛幼虫数量的增加而增大,其关系为正密度反应型,符合指数关系,其寄生率模型符合负加速型。在自然状态下,1头花绒坚甲从春季第一代开始到秋季混合世代结束,最多可以寄生光肩星天牛幼虫10~12头,80%的天牛幼虫被寄生后可繁育1~4头花绒坚甲;当光肩星天牛与花绒坚甲种群数量比率为1∶1.200 4时,花绒坚甲对光肩星天牛幼虫的寄生致死率基本稳定在50%~70%。

Study on the parasitic efficiency of Dastarcus helophoroides on Anoplophora glabripennis

In order to confirm the parasite characteristics of Dastarcus helophoroides to Anoplohora glabripennis,and to provide the basis for controlling Anoplophora glabripennis by Dastarcus helophoroides ,this paper analyzed the stem of poplars damaged by Anoplophora glabripennis in different months, and studied the rules of number changing of Anoplophora glabripennis and its natural enemy- Dastarcus helophoroides together with its control efficiency by using the methods of investigating analysis trees and statistic analysis. The results indicated that the parasitism rate of long horned beetle mature larva by Dastarcus helophoroides grew slowly from April to July,however it grew fast from the last ten-day of July to the last ten-day of September. The population of Dastarcus helophoroides in the boring tunnels reached the highest when the boring tunnels of the damaged stumpages got to 30-45. The population of Dastarcus helophoroides in living larvae tunnels of longhorn beetle increased along with the rise of the amount of larva. Their relationships were direct proportion. The parasitism model was invertebrate type. In one year,a Dastarcus helophoroides could parasitize at best 10-12 longhorn beetle larvae from the first generation in spring to the last generation in autumn; the death parasitism of Dastarcus helophoroides on big larva of Anoplophora glabripennis stayed at 50%-70%. After being parasitized 80% of Anoplophora glabripennis could breed 1-4 Dastarcus helophoroides.