疑山郭公虫对纵坑切梢小蠹捕食作用研究

Studies on Predation of Thanasimus dubius(Col.: Cleridae) on Tomicus piniperda(Col.: Scolytidae)

研究了疑山郭公虫对纵坑切梢小蠹成虫捕食量及对纵坑切梢小蠹繁殖过程和繁殖率的影响。在室温为22～24℃条件下，繁殖期疑山郭公虫平均每天可捕食纵坑切梢小蠹成虫0．61±0．043头。在实验室内，先将纵坑切梢小蠹引入云南松新鲜木段，7d后再引入疑山郭公虫成虫。结果表明：疑山郭公虫成虫对纵坑切梢小蠹成虫的产卵过程形成干扰，从而导致后者繁殖率下降。疑山郭公虫幼虫可以捕食木段内纵坑切梢小蠹幼期各虫态，捕食率为8．3％。在野外，将疑山郭公虫成虫放到受到纵坑切梢小蠹危害的树干上，再用尼龙网将其包裹起来。研究结果表明，疑山郭公虫对树干内纵坑切梢小蠹幼期（幼虫和蛹）的捕食率大体为10．6％。疑山郭公虫对繁殖期纵坑切梢小蠹的影响主要包括捕食繁殖期纵坑切梢小蠹成虫、干扰纵坑切梢小蠹繁殖过程以及捕食纵坑切梢小蠹幼虫等。研究初步认为，疑山郭公虫对纵坑切梢小蠹种群增长具有明显控制作用。

Thanasimus dubius （Col. ： Cleridae） is one of the main natural enemies of many bark beetles, and shows an essential natural control to the beetle population. The present paper studied the predation of Thanasimus dubius on Tomicus piniperda （ Col. ： Scolytidae） adults, as well as influences of the clerid predation on the bark beetle reproduction processes and reproduction rate. At room temperature of 22～24℃, one clerid female adult may averagely feed on 0.61 bark beetle adults （SE=±0. 043 ） a day. In the laboratory, we placed the clerid adults into Yunnan pine （Pinus yunnanensis） logs in which T. piniperda adults have been introduced. The result showed that, Thanasimus dubius adults can interfere reproduction processes of the beetle, causing the decreasing of the beetle reproduction rate. Thanasimus dubius larvae preyed all young stages of the beetle inside logs, recorded predation rate of 8.3%. In the field, we placed Thanasimus dubius adults on the stems of the damaged Yunnan pine trees and then covered the stems with nylon screen. This study demonstrated that the clerid preyed 10.6% of larvae and pupae of Tomicus piniperda living beneath the bark. The present study indicated that Thanasimus dubius may influence Tomicus piniperda reproduction through three aspects at least, feeding on the bark beetle adults, interfering the reproduction processes of the bark beetle, as well as preying the beetle larvae and pupae, and was so regarded to play a substantial role in control of Tomicus piniperda population.