Genetic mechanisms underlying feeding behaviour in silkworm larvae

The silkworm, an economically important insect that feeds almost exclusively on mulberry leaves, has emerged as a pivotal model for understanding the genetic basis of feeding behaviour in herbivorous specialists. Recent advances have begun to unravel the complex molecular networks that enable efficient host plant recognition, nutrient intake and metabolic adaptation. Feeding behaviour in silkworm larvae is governed by a multi-layered regulatory system that coordinates peripheral detection, internal organ sensing and neuroendocrine regulation. Key players include gustatory and odorant receptors, odorant-binding proteins, odorant-degrading enzymes, neuropeptides and transcription factors, all functioning in a coordinated, tissue-specific manner. In this review, we synthesize current knowledge of these genetic mechanisms within an integrative framework that links peripheral chemosensation and internal organ sensing to neuropeptide regulation and ultimately to behavioural output. We further discuss how comparative and evolutionary perspectives illuminate the genomic and adaptive evolution of mulberry specialization. We also consider emerging regulatory layers, including epigenetic modifications and the microbiota-gut-brain axis, which have been implicated in feeding behaviour in other insects but remain largely unexplored in the silkworm. Finally, we highlight emerging technologies that will advance research in this field, providing a foundation for improving artificial diet-based sericulture.