The threat of the fall armyworm to Asian rice production amplified by the brown planthopper

There is concern in Asia that the recently invaded fall armyworm (FAW), a major pest of maize, may adapt to feed on rice. We found that the brown plant hopper (BPH) may contribute to this risk. BPH-infested rice plants strongly attracted FAW moths to oviposition on rice plants. Although FAW caterpillars developed relatively poorly on rice, they did survive on young rice plants and readily pupated in exceedingly moist soils, typical for rice cultivation. The enhanced attractiveness of rice caused by BPH may facilitate FAW to quickly adapt to rice. Our findings reveal a new host range expansion mechanism for invasive herbivorous insects and reveal a need for monitoring and protection strategies in rice cultivation areas where BPH occurs.

亚洲地区近日存在一项科研担忧：新近入侵的草地贪夜蛾（fall armyworm, FAW）作为玉米的重大害虫，或会演化出取食水稻的适应性。本研究发现，褐飞虱（brown plant hopper, BPH）或会加剧这一风险——受褐飞虱侵染的水稻植株会显著吸引草地贪夜蛾成虫在水稻植株上产卵。尽管草地贪夜蛾幼虫在水稻上的发育状况相对欠佳，但它们仍可在幼龄水稻植株上存活，并能在水稻种植典型的高湿土壤中顺利化蛹。褐飞虱介导的水稻吸引性提升，或会推动草地贪夜蛾快速适应水稻寄主。本研究揭示了入侵植食性昆虫寄主范围扩张的全新机制，同时提示在褐飞虱发生的水稻种植区域，需制定相应的监测与防控策略。