Department of Evolutionary Animal Ecology, Bayreuth University, Bayreuth, Germany.
Sci Rep. 2022 Jun 1;12(1):9130. doi: 10.1038/s41598-022-12993-w.
The parasitoid wasp Trichopria drosophilae is promising as a biocontrol agent for controlling the ubiquitous pest Drosophila suzukii (Matsumura). Crucial for the successful implementation of any biocontrol agent is a high parasitisation rate by the parasitoid. Most studies investigating the parasitisation rate of D. suzukii pupae have focused on parasitisation in the fruit or in a petri dish. However, the predominant pupation site of D. suzukii in the field is the soil. Unfortunately, little is known on how well parasitoid wasps can detect and parasitise pupae of D. suzukii buried in the soil. Therefore, we conducted soil parasitisation experiments of T. drosophilae on D. suzukii pupae using two pupation depths in three different soil types (loamy sand, loam, and clay). In all three soil types, we found generally low D. suzukii pupae parasitisation rate by T. drosophilae, independent of the pupation depth. The pupation behaviour of D. suzukii and the parasitisation behaviour of T. drosophilae are discussed in detail. For pest control in most soil types, our results mean that the number of D. suzukii larvae pupating in the soil should be reduced, e.g., by adding a layer of sandy soil or covering the soil with plastic mulch. This might increase the probability of success when using T. drosophilae as a biocontrol agent.
寄生于果蝇的寄生蜂 Trichopria drosophilae 有望成为防治普遍存在的害虫果蝇 suzukii (Matsumura) 的生物防治剂。对于任何生物防治剂的成功实施，关键是寄生蜂的高寄生率。大多数研究都集中在果蝇蛹在果实或培养皿中的寄生率上。然而，果蝇 suzukii 在田间的主要化蛹地点是土壤。不幸的是，对于寄生蜂如何能够检测和寄生埋藏在土壤中的果蝇 suzukii 蛹知之甚少。因此，我们在三种不同的土壤类型（壤土、壤土和粘土）中，使用两种化蛹深度，对 T. drosophilae 对 D. suzukii 蛹进行了土壤寄生实验。在所有三种土壤类型中，我们发现 T. drosophilae 对 D. suzukii 蛹的寄生率普遍较低，而与化蛹深度无关。详细讨论了果蝇 suzukii 的化蛹行为和 T. drosophilae 的寄生行为。对于大多数土壤类型的害虫防治，我们的结果意味着应该减少在土壤中化蛹的果蝇 suzukii 幼虫数量，例如，通过添加一层沙土或用塑料覆盖土壤。这可能会增加使用 T. drosophilae 作为生物防治剂的成功概率。
