Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 90112, Thailand; Department of Biotechnology, Faculty of Science and Technology, Thammasat University, Rangsit, Pathum Thani 12121, Thailand.
Department of Forest Protection and Wildlife Management, Faculty of Forestry and Wood Technology, Mendel University in Brno, Zemědělská 3, Brno 613 00, Czech Republic.
Chemosphere. 2018 Jul;202:491-497. doi: 10.1016/j.chemosphere.2018.03.134. Epub 2018 Mar 21.
Even though pesticides can have various sublethal effects on behaviour of biocontrol agents, no study to date has investigated the effects of pesticides on the prey choice of generalist predators. Prey choice of generalist predators is among key factors determining the predation pressure they exert on pests, because it influences fitness of predators and consequently their densities and per capita capture rate. Here, we investigated the effect of Integro (a.i. methoxyfenozide) and SpinTor 480 Sc (a.i. spinosad) on prey choice and predatory activity of the spider Philodromus cespitum, which is known significantly to reduce hemipteran and dipteran pests in fruit orchards. We compared the prey preferences of philodromids between the psyllid pest Cacopsylla pyri (Hemiptera, Psyllidae) and beneficial Theridion sp. spiders in laboratory experiments. We found that both pesticides altered the prey preferences of philodromids. While the philodromids in a control treatment preferred theridiid spiders over the psyllid pest, philodromids in the pesticide treatments exhibited no significant prey preferences. The changes in prey preferences were caused by increased predation on the psyllids, while the predation on the theridiid remained similar. We suggest that the changes in prey preferences might theoretically be due to 1) impaired sensory systems, 2) altered taste, and/or 3) altered mobility. In combination with other studies finding reduced predation on fruit flies in P. cespitum after exposure to SpinTor, our results indicate that the sublethal effects of pesticides on predatory behaviour of generalist predators can depend on prey type and/or prey community composition.
尽管杀虫剂可能对生物防治剂的行为产生各种亚致死影响，但迄今为止，尚无研究调查杀虫剂对通用捕食者的猎物选择的影响。通用捕食者的猎物选择是决定它们对害虫施加捕食压力的关键因素之一，因为它会影响捕食者的适应性，进而影响它们的密度和个体捕获率。在这里，我们研究了 Integro（a.i. 甲氧虫酰肼）和 SpinTor 480 Sc（a.i. 多杀菌素）对蜘蛛 Philodromus cespitum 的猎物选择和捕食活动的影响，已知该蜘蛛在水果园中显著减少半翅目和双翅目害虫。我们在实验室实验中比较了叶螨 Cacopsylla pyri（半翅目，叶蝉科）和有益的 Theridion sp. 蜘蛛在拟叶螨中的猎物偏好。我们发现，这两种杀虫剂都改变了拟叶螨的猎物偏好。虽然对照处理中的拟叶螨更喜欢捕食 Theridion sp. 蜘蛛而不是叶蝉害虫，但处理中的拟叶螨没有表现出明显的猎物偏好。猎物偏好的变化是由于对叶蝉的捕食增加，而对 Theridion sp. 的捕食保持相似。我们认为，猎物偏好的变化理论上可能是由于 1）感觉系统受损，2）味觉改变，和/或 3）活动性改变。结合其他研究发现，暴露于 SpinTor 后，P. cespitum 对果蝇的捕食减少，我们的结果表明，杀虫剂对通用捕食者捕食行为的亚致死影响可能取决于猎物类型和/或猎物群落组成。
