Comparative transcriptomics reveal universal and compound-specific mechanisms of insecticide response in the mulberry looper (Phthonandria atrilineata)

Abstract

Understanding insect molecular responses to different insecticides is essential for sustainable pest management. This study presents a comprehensive transcriptomic analysis of Phthonandria atrilineata exposed to insecticides with distinct modes of action. RNA sequencing was performed on larvae treated with organophosphates (trichlorfon, malathion, and trichlorfon-malathion mixture) and mitochondrial inhibitors (methoxyfenozide and chlorfenapyr). Our analysis revealed both mechanism-specific responses and conserved xenobiotic defense programs. We identified 180 commonly upregulated genes involved in detoxification and sensory perception pathways, and 357 commonly downregulated genes indicating suppression of carbohydrate metabolism and developmental processes under chemical stress. Fuzzy clustering revealed nine distinct expression modules, with organophosphates primarily affecting neuronal functions while mitochondrial inhibitors triggered metabolic reprogramming centered on energy balance and protein homeostasis. Additionally, the trichlorfon-malathion mixture produced synergistic effects on endocrine signaling pathways. These findings illuminate the molecular architecture of insecticide responses, providing valuable insights for pest management strategies and resistance monitoring in agricultural settings.