黄带犀猎蝽对黏虫3龄幼虫的捕食功能反应

Predatory functional responses of assassin bug Sycanus croceovittatus to the third-instar larvae of oriental armyworm Mythimna separata

为绿色防控黏虫Mythimna separata,在实验室条件下研究黄带犀猎蝽Sycanus croceovittatus4、5龄若虫和雌、雄成虫对不同密度黏虫3龄幼虫的捕食功能反应、搜寻效应和自身密度干扰效应。结果表明,黄带犀猎蝽4、5龄若虫和雌、雄成虫对黏虫3龄幼虫的捕食功能反应均符合HollingⅡ和HollingⅢ两种模型;在拟合HollingⅡ模型中,黄带犀猎蝽4、5龄若虫和雌、雄成虫对黏虫3龄幼虫的日均最大捕食量分别为9.709、30.075、16.215和24.319头,控害效能分别为13.544、36.180、28.377和30.739,其中5龄若虫对黏虫3龄幼虫的控害效能最大;在拟合HollingⅢ模型中,黄带犀猎蝽4、5龄若虫和雌、雄成虫的日均最大捕食量分别为8.855、20.960、14.700和18.180头,最佳寻找密度分别为4.084、8.497、5.370和7.322头/盒;黄带犀猎蝽4、5龄若虫和雌、雄成虫搜寻效应与黏虫密度呈负相关关系,平均每头黄带犀猎蝽的捕食量与其自身密度呈负相关;黄带犀猎蝽5龄若虫相较于4龄若虫和雌、雄成虫对黏虫3龄幼虫有较高的捕食能力,更具有田间推广应用潜力。

For sustainable control of oriental armyworm Mythimna separata,the 4th-,5th-instar nymphs and adults of Sycanus croceovittatus were tested under laboratory conditions for their functional responses to and searching efficiency against the 3rd-instar M.separata larvae as well as the effect of conspecific density on their predation success.The results showed that the functional responses during all S.croceovittatus developmental stages fitted the HollingⅡand HollingⅢdisc equations.In the Holling II model,the 4th-and 5th-instar nymphs and female and male adults of S.croceovittatus had a daily maximum consumption of 9.709,30.075,16.215 and 24.319,and a predation capacity of13.544,36.180,28.377 and 30.739,respectively,with the 5th-instar nymph showing the best pest control efficiency.According to the HollingⅢmodel,the 4th-and 5th-instar nymphs and female and male adults of S.croceovittatus had a daily maximum consumption of 8.855,20.960,14.700 and 18.180,and an optimal searching density of 4.084,8.497,5.370 and 7.322 per box,respectively.The searching efficiency was negatively correlated with the pest density.The average predation capacity per predator was negatively correlated with the predator density.In general,the 5th-instar nymph of S.croceovittatus had the highest predation ability against M.separata 3rd-instar larvae,which was significantly stronger than the 4th-instar nymph,female and male adults,and also has the potential for field popularization and application.