六斑月瓢虫对柑橘木虱的捕食作用

Predatory Responses of Cheilomenes sexmaculata to Diaphorina citri

亚洲柑橘木虱Diaphorina citri Kuwayama是柑橘、脐橙等芸香科植物上的重要害虫,六斑月瓢虫Menochilus sexmaculata(Fabricius)是我国南方地区常见的天敌昆虫。为了评价六斑月瓢虫对柑橘木虱的控害潜能,在室内条件下分别测定了六斑月瓢虫的1龄、4龄幼虫和成虫对柑橘木虱的低龄、高龄若虫和成虫的捕食功能反应、搜寻效应和自身密度干扰反应。结果表明,六斑月瓢虫的幼虫和成虫对柑橘木虱的若虫和成虫的捕食功能反应均能较好地拟合HollingⅡ型圆盘方程。其中六斑月瓢虫1龄幼虫对柑橘木虱低龄若虫的日最大捕食量为55.55头/d、高龄若虫为66.66头/d;六斑月瓢虫4龄幼虫对柑橘木虱低龄若虫的日最大捕食量为500头/d、高龄若虫为200头/d、成虫为200头/d;六斑月瓢虫成虫对柑橘木虱低龄若虫的日最大捕食量为333.33头/d、高龄若虫为250头/d、成虫为125头/d。六斑月瓢虫对柑橘木虱的搜寻效应随着猎物密度的增大而降低。由于捕食者自身密度的干扰,当柑橘木虱密度不变时随着六斑月瓢虫密度的增加,瓢虫单头捕食量减小、捕食效率降低、分摊竞争强度增大。本研究为田间应用六斑月瓢虫防治柑橘木虱,控制柑橘黄龙病的传播提供了理论依据。

Diaphorina citri Kuwayama is an important pest of citrus,navel oranges,and other members of Rutaceae family.Cheilomenes sexmaculata(Fabricius)is a common insect natural enemy in southern China.To assess the potential of C.sexmaculata to manage D.citri,the predatory functional response,search efficacy,and self-density interference response of the larvae(1st and 4th instar)and adults against various life stages of D.citri(early,late instar nymphs,and adults)were examined.Our findings demonstrated that the predatory functional response of Holling II is present in C.sexmaculata larvae and adults.The maximum daily predation amounts of the 1st instar larvae of C.sexmaculata against the early and late instar nymphs of D.citri was 55.55 and 66.66 individuals,respectively.The maximum daily predation amounts of the 4th instar larvae of C.sexmaculata against the early,late instar nymphs and adults of D.citri was 500,200 and 200 individuals,respectively.The maximum daily predation amount of the C.sexmaculata adults against early,late instar nymphs and adults of D.citri was 333.33,250 and 125 individuals,respectively.With an increase in prey density,C.sexmaculata's ability to find D.citri reduced.With a rise in interference from the predator’s density at a constant D.citri density,C.sexmaculata’s predation effectiveness fell while its sharing competition intensity increased.This study offers a theoretical foundation for employing C.sexmaculata to control D.citri and Huanglongbing in the field.