ABSTRACT

Native hyperparasitoids may readily expand their host range by including non-native parasitoids that are introduced in classical biological control of pest insects. Here we report our observation on biology of Cheiloneurus nankingensis (Hymenoptera: Encyrtidae), an obligate hyperparasitoid attacking non-native parasitoid Aenasius arizonensis residing in Phenacoccus solenopsis mealybugs that have invaded into Asian regions. We measured durations of antennae-tapping, ovipositor-drilling and ovipositor-probing/ovipositing behaviours by C. nankingensis wasps on parasitised mealybugs with the host at either larval or pupal stage and on the unparasitised mealybug as the control. The ovipositor-probing/ovipositing duration was much longer on a pupal host than on the larval while shortest on the control. We then observed offspring development progression of C. nankingensis at attacking either egg, larva or pupa of its host by daily dissecting hyperparasitised mealybugs. The development was faster in a larval or pupal host than in the egg. Finally, our measurements of the reproductive output showed that C. nankingensis wasps during 14 days after the emergence attacked more parasitised mealybugs and produced more offspring reaching adulthood when ovipositing in the mealybug with a host larva than with a pupa. Our results from this study suggest that C. nankingensis may employ the ovipositor to probe for the host within a mealybug and the host at the larval stage is of high quality for the reproduction.

摘要

本地超寄生蜂可以通过包含在害虫的经典生物控制中引入的非本地寄生蜂来容易地扩大其寄主范围。在这里，我们报告了我们对Cheiloneurus nankingensis （膜翅目：Encyrtidae）生物学的观察，这是一种专性的超寄生蜂，攻击非本地寄生蜂Aenasius arizonensis ，居住在已入侵亚洲地区的Phenaccus sonopsis粉蚧中。我们测量了南京 C. nankingensis触角敲击、产卵器钻探和产卵器探测/产卵行为的持续时间黄蜂寄生在幼虫期或蛹期的寄生粉蚧上，并以未寄生的粉蚧为对照。蛹寄主的产卵器探测/产卵持续时间比幼虫长得多，而对照的最短。然后，我们通过每天解剖过度寄生的粉蚧来观察南京小蠹攻击其宿主的卵、幼虫或蛹的后代发育进程。幼虫或蛹宿主的发育比卵更快。最后，我们对繁殖输出的测量表明，南京长丝草黄蜂在羽化后的 14 天内攻击更多的寄生粉蚧，并在粉蚧与宿主幼虫一起产卵时比在蛹中产卵时产生更多的成年后代。我们的研究结果表明，南京粉虱可能利用产卵器来探测粉蚧体内的宿主，并且幼虫阶段的宿主对于繁殖来说是高质量的。