
儘管變葉山螞蝗會釋放出已知具有生物活性的揮發物，但這些揮發物本身是否足以驅趕草地貪夜蛾仍需進一步研究，因為其他因素，如邊界作物的影響、地下相互作用以及變葉山螞蝗的其他驅蟲特性，也可能在保護玉米免受草地貪夜蛾侵害方面發揮作用。


coremsg

Push-pull systems for sustainable pest management of crop plants employ repellent stimuli from intercrops (“push”) to repel herbivores and attract their predators and parasitoids, and attracting stimuli from border plants (“pull”) to lead herbivorous insects out of the crop. The most widespread implementation, intercropping with the legume Desmodium , reduces herbivory damage from the invasive fall armyworm (FAW) Spodoptera frugiperda . However, the three publications to date investigating underlying mechanisms disagree whether the Desmodium intercrop emits bioactive volatiles that repel FAW. We aimed to resolve this controversy by measuring volatile emission from Desmodium intortum (greenleaf Desmodium ) and D. incanum intercrops in push-pull fields, and assaying their effects on the behavior of the FAW in oviposition and wind tunnel choice bioassays. We detected many volatile substances in the headspaces of both Desmodium species, which exhibited similar profiles, including substances previously reported to repel lepidopteran herbivores. FAW moths preferred to oviposit on maize over Desmodium , but not on maize further from versus closer to Desmodium plants that were inaccessible to the moths, but sharing the air. In a wind tunnel bioassay, the moths tended to prefer maize volatiles over a combination of volatiles from maize and D. intortum , but not D. incanum . In conclusion, we found D. intortum and D. incanum to emit volatiles that have been shown to be bioactive, and FAW moths to prefer maize over either Desmodium species. Moreover, additional mechanisms are likely important for reducing FAW damage to maize under push-pull cultivation.

### Competing Interest Statement

The authors have declared no competing interest.

Desmodium Volatiles in “Push-Pull” Agriculture and Protection Against the Fall Armyworm, Spodoptera frugiperda

應用於-推拉式-農業的變葉山螞蝗揮發物及其對草地貪夜蛾-秋行蟲-的防治效果


應用於「推拉式」農業的變葉山螞蝗揮發物及其對草地貪夜蛾 (秋行蟲) 的防治效果
