Oviposition and feeding preferences of the groundnut leaf miner (Bilobata subsecivella, Lepidoptera: Gelechiidae) on selected host plants under controlled environmental conditions

<br>The groundnut leaf miner (GLM), <i>Bilobata subsecivella</i>, is a highly destructive pest of legume crops, particularly groundnut (<i>Arachis hypogaea</i>) and soybean (<i>Glycine max</i>), but it also infests wild species such as hairy indigo (<i>Indigofera hirsuta</i>). However, little is known about how its behavioural preferences influence its spatial distribution and population dynamics. Such information is crucial for informing effective pest control measures, especially within the framework of Integrated Pest Management (IPM), which emphasises ecological understanding as the foundation for sustainable control strategies. This study compared infestation levels of GLM on groundnut, soybean, and hairy indigo; evaluated female GLM oviposition preferences among these three plants; and determined the preferred host plant for GLM larval feeding, using non-choice, two-choice, and three-choice assays. Results showed that all three host plants were suitable hosts for GLM feeding, though the intensity and mining patterns varied. Groundnut displayed broader blotch mines, hairy indigo had primarily linear mines, and soybean displayed intermediate characteristics.Oviposition trials revealed that soybean was the most preferred host for egg laying; however, it did not support successful larval development due to early defoliation. In contrast, groundnut was the most suitable host for infestation and larval performance. Hairy indigo, though least preferred for oviposition, supported larval development and was the only host on which adult emergence occurred in the second infestation trial. These findings highlight a significant mismatch between oviposition preference and larval performance, underscoring the importance of considering both host selection and developmental success when evaluating host suitability. The observed differences observed in feeding, oviposition and infestation patterns suggest that host plant suitability is strongly influenced by chemical, structural, and defensive traits. Future research should focus on identifying the specific cues driving oviposition and feeding intensity, as this knowledge could guide sustainable management strategies for GLM in legume cropping systems.

花生潜叶蛾（groundnut leaf miner, 缩写GLM，*Bilobata subsecivella*）是豆科作物的毁灭性害虫，尤其为害花生（*Arachis hypogaea*）与大豆（*Glycine max*），同时亦可侵染硬毛木蓝（*Indigofera hirsuta*）等野生豆科物种。然而，目前学界对其行为偏好如何影响空间分布与种群动态的认知仍较为匮乏。此类信息对于制定高效害虫防治策略至关重要，尤其在综合害虫管理（Integrated Pest Management, IPM）框架下——该理念强调以生态学认知作为可持续防治策略的核心基础。本研究对比了GLM在花生、大豆及硬毛木蓝上的侵染水平，评估了雌蛾在三种寄主间的产卵偏好，并通过无选择、双选择及三选择试验，明确了GLM幼虫取食的最适寄主植物。研究结果显示，三种寄主植物均适宜GLM取食，但为害强度与潜叶模式存在显著差异：花生的潜道多为宽大的斑块状，硬毛木蓝的潜道以线性为主，大豆的潜道则呈现中间型特征。产卵试验表明，大豆是雌蛾最偏好的产卵寄主，但由于寄主早期落叶，无法支持幼虫成功完成发育。与之相对，花生是最适宜GLM侵染与幼虫生长发育的寄主。硬毛木蓝虽产卵偏好程度最低，却可支持幼虫完成发育，且在第二次侵染试验中是唯一能实现成虫羽化的寄主。上述发现揭示了产卵偏好与幼虫适合度间存在显著错配，凸显了在评估寄主适宜性时，需同时考量寄主选择行为与幼虫发育成功率的重要性。本次研究观察到的取食、产卵及侵染模式差异表明，寄主植物的适宜性强烈受其化学、结构与防御性状的影响。未来研究应聚焦于识别驱动产卵与取食强度的特异性信号，该研究成果可为豆科种植系统中GLM的可持续防治策略提供科学指导。