Evolution, Composition and Functional Mechanisms of Lepidopteran Venoms: A Comprehensive Review

Animal venoms are of considerable scientific interest due to the risks they pose and their value in understanding evolution, ecology, pharmacology, biodiscovery and biotechnology. In Lepidoptera, venom systems have evolved independently multiple times, primarily as defensive adaptations that protect the larval stages from predators. Although these venoms are consistently produced by cuticle-derived structures and specialized setae, they display remarkable variation in chemical composition, mode of action and biological effects, highlighting their diverse evolutionary origins. Lepidopteran envenomation most commonly causes pain, irritation and inflammatory responses in humans; however, certain species can induce severe or fatal outcomes, including hemorrhagic syndromes in humans and veterinary conditions such as equine amnionitis and fetal loss. Despite their medical and ecological importance, only a small number of venom components have been fully characterized to date. Key examples include coagulation-disrupting toxins from Lonomia obliqua (Saturniidae) and nociceptive cecropin-like peptides from Doratifera vulnerans (Limacodidae). This review synthesizes current knowledge on the evolution, diversity and mechanistic functions of lepidopteran venoms and highlights significant gaps that warrant future investigation. Keywords: Lepidoptera, venom, chemical diversity, envenomation, peptide, evolution