花绒寄甲初孵幼虫对替代寄主寄生力测定

Parasitism of Alternative Host by The Initial Larva of Dastarcus helophoroides

花绒寄甲是我国重大林业害虫天牛的主要天敌,目前已经实现了其室内人工饲养,但由于幼虫对替代寄主的寄生率较低,大大增加了生产成本,严重影响花绒寄甲实现工厂化生产。为提高替代寄主的利用率,本研究在实验室内测定了花绒寄甲前5日龄初孵幼虫对替代寄主寄生力,及初孵幼虫接种到替代寄主体表后不同时间的存活率,试验结果表明:(1)各处理替代寄主的出虫率呈极显著差异。其中2日龄幼虫接种替代寄主后平均出虫数最大,为4.60头,最小的为5日龄幼虫,2.43头。(2)对于同日龄花绒寄甲初孵幼虫,接种到替代寄主体表后不同时间存活率呈显著差异,且各日龄初孵幼虫接种后5 d的存活率均为最低,分别为50.67%、55.67%、48.33%、48.00%和33.00%。该研究结果可为花绒寄甲的人工繁育提供理论依据。

Dastarcus helophoroides Faimaire is the main natural enemy of the major forest pest longicorns in China, which has been realized for mass-rearing. However, its low parasitism rate of the larvae to alternative hosts seriously affected the factory production. To improve the utilization rate of alternative hosts, parasitism of alternative hosts by the initial larva of Dastarcus helophoroides were determined. The results showed that worm rate of alternatives differed significantly among different treatments, and 2-day-old larvae gave the most adults（4.60 heads）, while 5-day-old ones did the smallest（2.43 heads）. Also the survival rate in different time was determined from the initial larva to alternative hosts. The results showed that the survival rate at different times differed significantly for the same age larvae. 5 days after inoculation caused the lowest survival rate, which were 50.67%, 55.67%, 48.33%, 48.00%, and 33.00%. These findings provided theoretical basis for mass-rearing of Dastarcus helophoroides.