Entomopathogenic Nematodes Combined with Adjuvants Presents a New Potential Biological Control Method for Managing the Wheat Stem Sawfly, Cephus cinctus (Hymenoptera: Cephidae)

The wheat stem sawfly, (Cephus cinctus Norton) Hymenoptera: Cephidae, has been a major pest of winter wheat and barley in the northern Great Plains for more than 100 years. The insect's cryptic nature and lack of safe chemical control options make the wheat stem sawfly (WSS) difficult to manage; thus, biological control offers the best hope for sustainable management of WSS. Entomopathogenic nematodes (EPNs) have been used successfully against other above-ground insect pests and adding adjuvants to sprays containing EPNs has been shown to improve their effectiveness. We tested the hypothesis that adding chemical adjuvants to sprays containing EPNs will increase the ability of EPNs to enter wheat stems and kill diapausing WSS larvae. This is the first study to test the ability of EPNs to infect the WSS, C. cinctus, and test EPNs combined with adjuvants against C. cinctus in both the laboratory and the field. Infection assays showed that three different species of EPNs caused 60-100% mort...

小麦茎锯蜂（Cephus cinctus Norton）隶属于膜翅目（Hymenoptera）茎蜂科（Cephidae），一个多世纪以来始终是北美大平原北部冬小麦与大麦的主要害虫。该昆虫生性隐蔽，且缺乏安全的化学防控手段，致使小麦茎锯蜂（wheat stem sawfly, WSS）防控难度极大；因此，生物防治是实现WSS可持续防控的最优途径。昆虫病原线虫（Entomopathogenic nematodes, EPNs）已成功应用于多种其他地上害虫的防控，且已有研究证实，在含有EPNs的喷施液中添加助剂可显著提升其防控效果。本研究验证了如下假说：在含有EPNs的喷施液中添加化学助剂，可增强EPNs侵入小麦茎秆并杀死滞育期WSS幼虫的能力。本研究为首个检测EPNs侵染小麦茎锯蜂（C. cinctus）能力，且在实验室与田间条件下评估EPNs与助剂复配对C. cinctus防治效果的相关研究。侵染试验结果显示，3种不同的EPNs可造成60%~100%的死亡率……