释放花绒寄甲防治危害白蜡的云斑天牛

Biocontrol of Batocera horsfieldi(Coleoptera:Cerambycidae)Attacking Ash Trees by Releasing the Parasitoid Dastarcus helophoroides(Coleoptera:Bothrideridae)

在地处黄河三角洲的山东省东营市和滨州市,选取8个受害严重的白蜡林作为试验样地,在云斑天牛幼虫期释放花绒寄甲卵和成虫,然后调查和统计天敌释放前后白蜡树的被害株率、天牛的株虫口数,计算出花绒寄甲对云斑天牛的防治效果。结果表明:林间释放花绒寄甲卵和成虫对云斑天牛均有良好的控制作用。在释放花绒寄甲卵的5个试验林中,释放后第2年的平均株虫口校正减退率为73.16%,平均被害株校正减退率为72.36%;在释放花绒寄甲成虫的3个试验林中,释放后第2年的平均株虫口校正减退率为77.20%,平均被害株校正减退率为69.68%。对释放花绒寄甲卵和成虫的防治效果进行比较表明,释放花绒寄甲成虫的防治效果略高于释放卵的林分,但二者差异不显著,说明在云斑天牛生物防治中,释放花绒寄甲2种虫态的天敌均不失为有效和良好的技术,而卵的成本低,值得在生产防治中大力推广应用。

A biocontrol program was carried out by releasing the parasitoid Dastarcus helophoroides（Coleoptera：Bothrideridae） of the longhorn beetle Batocera horsfieldi（Coleoptera：Cerambycidae）,an important stem-borer of ashes（Fraxinus velutina） in shandong,the Huanghe Yellow River Delta in the present study.Adults and eggs of D.helophoroides were released in fields in eight plots in Dongying and Binzhou City.Control effect was evaluated by two investigation indexes,i.e.,infested trees and the longhorn beetle larvae density.The biocontrol results showed that releasing eggs and adults of the parasitoid were able to effectively control B.horsfieldi.After the release of the parasitoid for two years,in the five plots of release the parasitoid eggs,the mean correction reducing rate of the longhorn beetle larvae was 73.16% per tree,and the mean correction reducing rate of infested trees was 72.36%.In three plots of releasing the parasitoid adults,mean correction reducing rate of the longhorn beetle larvae was 77.20% per tree,and the mean correction reducing rate of infested trees was 69.68%.It was showed that the control results by releasing adults of the parasitoid were a little better than releasing eggs,but the difference was not significant.Thus,the technique of releasing eggs of the parasitoid would be worth extending in the large area control of the pest for low cost of its eggs in mass rearing.