Almohamad Raki, Hance Thierry
Department of Plant Protection, Faculty of Agriculture-Alfurat University, Deir Ezzor, Syria.
Insect Sci. 2014 Apr;21(2):181-8. doi: 10.1111/1744-7917.12037. Epub 2013 Jul 21.
Intraguild predation (IGP) can be an important factor influencing the effectiveness of aphid natural enemies in biological control. In particular, aphid parasitoid foraging could be influenced by the presence of predators. This study investigated the effect of larvae of the predatory hoverfly Episyrphus balteatus DeGeer (Diptera: Syrphidae) and the multicolored Asian ladybird Harmonia axyridis Pallas (Coleoptera: Coccinellidae) on the foraging behavior of the aphid parasitoid, Aphidius ervi Haliday (Hymenoptera: Aphidiidae) in choice experiments using a leaf disc bioassay. Wasp response to chemical tracks left by those predator larvae was also tested. Parasitoid behavior was recorded using the Observer (Noldus Information Technology, version 5.0, Wageningen, the Netherlands). The experiments were conducted under controlled environmental conditions using leaves of the broad bean plant, Vicia faba L. (Fabaceae) with Myzus persicae Sulzer (Homoptera: Aphididae) as the host complex. A. ervi females avoided aphid patches when larvae of either predator were present. A similar avoidance response was shown by A. ervi to aphid patches with E. balteatus larval tracks, whereas no significant response was observed to tracks left by H. axyridis larvae. It was concluded that IG predator avoidance shown by the aphid parasitoid A. ervi may be a factor affecting their distribution among host patches.
集团内捕食（IGP）可能是影响蚜虫天敌生物防治效果的一个重要因素。特别是，蚜虫寄生蜂的觅食行为可能会受到捕食者存在的影响。本研究在叶碟生物测定的选择实验中，调查了捕食性食蚜蝇黑带食蚜蝇（双翅目：食蚜蝇科）幼虫和异色瓢虫（鞘翅目：瓢虫科）对蚜虫寄生蜂豌豆蚜茧蜂（膜翅目：蚜茧蜂科）觅食行为的影响。还测试了寄生蜂对这些捕食者幼虫留下的化学痕迹的反应。使用Observer（Noldus信息技术公司，版本5.0，荷兰瓦赫宁根）记录寄生蜂的行为。实验在可控环境条件下进行，使用蚕豆（豆科）叶片，以桃蚜（同翅目：蚜科）作为寄主复合体。当任一捕食者的幼虫存在时，豌豆蚜茧蜂雌蜂会避开蚜虫斑块。豌豆蚜茧蜂对有黑带食蚜蝇幼虫痕迹的蚜虫斑块也表现出类似的回避反应，而对异色瓢虫幼虫留下的痕迹未观察到明显反应。得出的结论是，蚜虫寄生蜂豌豆蚜茧蜂表现出的对集团内捕食者的回避可能是影响其在寄主斑块间分布的一个因素。
