Identification and Characterization of Cuticular Proteins in the Miridae Insect Apolygus lucorum

Insect cuticles exhibit remarkable resistance to environmental stresses, largely attributed to cuticular proteins (CPs), which are crucial for insect development and adaptation. CPs also contribute to insecticide resistance, making them a key focus in molecular entomology. Apolygus lucorum, a globally distributed omnivorous pest within the Miridae family (Hemiptera: Heteroptera), inflicts significant economic losses by damaging a wide range of crops. However, information on CPs in the Miridae family remains scarce, limiting our understanding of their molecular mechanisms of adaptation and resistance. Here, we performed a genome-wide identification of CPs in A. lucorum and reanalyzed transcriptomic data under insecticide exposure to identify resistance-related candidates. A total of 211 CPs were identified and classified into 10 subfamilies. Notably, the RR-2, Tweedle, and CPF families showed significant expansions compared to other hemipterans, likely driven by tandem duplication events, which may contribute to A. lucorum's broad environmental adaptability and host range. Expression profiling revealed two major patterns: one with peak expression during the nymphal stage and another maintained throughout the entire life cycle. Crucially, 75 CPs were upregulated following insecticide treatment, underscoring their potential role in resistance and their value as targets for pest control. Our findings provide a comprehensive foundation for future studies on the molecular functions of CPs in A. lucorum and their involvement in insecticide resistance, paving the way for novel management strategies.