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.