Soil-dwelling insect pests may cause considerable damage to crops worldwide, and their belowground lifestyle makes them hard to control. Amongst the most promising control agents for subterranean pests are soilborne entomopathogenic fungi (EPF) such as Metarhizium brunneum. Albeit EPF can be highly pathogenic to their target pest species under laboratory conditions, their efficacy in the field is often limited due to adverse environmental conditions. Here, we test for the first time if the efficacy of EPF can be improved when they are augmented with trap crops. In a field experiment, the M. brunneum strain ART2825 was combined with a trap crops mixture of six plant species and evaluated for its control effect of wireworms (Coleoptera: Elateridae). When both were combined in the main crop, potato damage was lowered on average by 42.5% and wireworm abundance by 50.8%. Single application of trap crops or EPF lowered damage/pest abundance only by 29.9%/15.89% and 34.7%/4.77%, respectively. Importantly, the strength of the synergistic pest control effect between trap crops and EPF increased disproportionately with increasing wireworm abundance. However, DNA-based gut content analysis showed that wireworms’ feeding preferences were not shifting toward the trap crops. Our findings demonstrate that combining trap crops with EPF improves the efficacy of the latter and leads to a synergistic control effect which magnifies with increasing wireworm abundance. Hence, the synergistic effect of EPF and trap crops might be a promising control strategy for soil-dwelling pests in general and significantly improve our abilities to manage soil pests environmentally friendly.

土壤害虫可能对全世界农作物造成相当大的损害，它们的地下生活方式使它们难以控制。最有前途的地下害虫防治剂是土传昆虫病原真菌 (EPF)，例如绿僵菌(Metarhizium brunneum ) 。尽管 EPF 在实验室条件下可能对其目标害虫物种具有高致病性，但由于不利的环境条件，其在田间的功效往往受到限制。在这里，我们首次测试了 EPF 的功效是否可以在使用陷阱作物增强时得到提高。在田间实验中，将M. brunneum菌株 ART2825 与六种植物的诱捕作物混合物结合，并评估其对金针虫（鞘翅目：Elateridae）的控制效果。当两者在主要作物中结合使用时，马铃薯损害平均降低了 42.5%，金针虫丰度平均降低了 50.8%。单独施用诱集作物或 EPF 仅分别降低损害/害虫丰度 29.9%/15.89% 和 34.7%/4.77%。重要的是，诱捕作物和 EPF 之间的协同害虫防治效果的强度随着金针虫丰度的增加而不成比例地增加。然而，基于 DNA 的肠道内容分析表明，金针虫的摄食偏好并未转向诱捕作物。我们的研究结果表明，将诱集作物与 EPF 结合可以提高后者的功效，并产生协同控制效果，该效果随着金针虫丰度的增加而放大。因此，EPF和陷阱作物的协同效应可能是一种有前景的土壤害虫控制策略，并显着提高我们环境友好地管理土壤害虫的能力。