The adaptive prowess of the lesser mealworm Alphitobius diaperinus (Coleoptera: Tenebrionidae): Insights from mouthpart morphology and mitogenomic analysis

The lesser mealworm, Alphitobius diaperinus (Panzer, 1797), is a pervasive pest known to infest stored products and poultry facilities worldwide, posing significant challenges for pest management. Understanding its adaptability to diverse environments is crucial for devising effective control strategies. This study investigated adult mouthparts and analyzed the mitogenome of A. diaperinus using specimens obtained from a cat litter box. The examination of mouthparts revealed notable intraspecific variations, suggesting potential adaptations to different ecological conditions. Analysis of the mitogenomes unveiled nucleotide variations in protein-coding genes (PCGs), ribosomal RNA genes (rRNAs), and the control region, with all mutations in PCGs being nonsynonymous, primarily occurring at the second codon positions. Evaluation of Ka/Ks ratios indicated purifying selection acting on the PCGs of A. diaperinus. Phylogenetic analyses consistently placed the newly sequenced sample within the same clade as previously sequenced A. diaperinus samples. The presence of A. diaperinus in cat litter highlights its remarkable adaptability to diverse habitats. Furthermore, intraspecific variation in mouthpart morphology and the mitogenome suggests ongoing adaptations to various food sources and environmental niches. These findings underscore the dynamic nature of A. diaperinus adaptations and emphasize the importance of continued research for effective pest management strategies.