《环境昆虫学报》

【目的】本研究以吐鲁番盆地三种优势荒漠拟步甲（何氏胖漠甲Trigonoscelis holdereri、谢氏宽漠甲Sternoplax szechenyi、隆胸鳖甲Colposcelis montivaga）为研究对象，【方法】通过气相色谱－质谱联用（GC-MS）技术解析其表皮碳氢化合物（CHCs）组成特征，探讨其对极端干旱环境的适应性及在分类上的应用。【结果】结果表明：CHCs组成与干旱适应：共鉴定44种CHCs，正构烷烃为核心成分（47.93%~53.57%），以C27、C29、C31等奇数长链烷烃为主，短链烷烃（ < C20）仅占4种，其中何氏胖漠甲含C34-C40超长链烷烃。异构烷烃以单甲基支链烷烃为主（34.74%~47.06%），多甲基烷烃（1.67%~5.41%）和烯烃（2.57%~6.28%）占比最低。主成分分析显示三种拟步甲CHCs组成高度相似，与沙漠蝗虫Schistocerca gregaria、红胡须蚁Pogonomyrmex barbatus等类群趋同，与湿润生境拟步甲趋异，验证了通过富集长链正构烷烃、增加单甲基支链烷烃及缩减多甲基烷烃的保水策略。基于11种关键差异CHCs的判别分析（Wilks＇λ = 0，P < 0.001）可有效区分三种物种，聚类结果与COI-28S联合基因系统发育树一致（BPP = 1.00），表明CHCs具有物种特异性分类潜力。热图分析显示种内CHCs相似度高于种间，支持其作为形态鉴定的补充工具。【结论】本研究揭示了三种拟步甲CHCs的干旱适应模式，并证实CHCs在同域种鉴定中的有效性，为解析荒漠昆虫环境适应机制提供参考依据。

英文摘要:

【Aim】This study investigated the cuticular hydrocarbon (CHC) profiles of three dominant desert tenebrionid beetles (Trigonoscelis holdereri, Sternoplax szechenyi, and Colposcelis montivaga) in the Turpan Basin【Methods】using gas chromatography-mass spectrometry (GC-MS), aiming to elucidate their adaptation to extreme aridity and taxonomic applications. 【Results】Key findings revealed: CHC composition and arid adaptation: A total of 44 CHCs were identified, dominated by n-alkanes (47.93%~53.57%) that primarily consisted of odd-numbered long-chain alkanes (C27, C29, C31) with only four short-chain alkanes ( < C20), while T. holdereri uniquely contained ultra-long-chain alkanes (C34-C40). Mono-methyl branched alkanes constituted the major iso-alkane fraction (34.74%~47.06%), while poly-methylated alkanes (1.67%~5.41%) and alkenes (2.57%~6.28%) were minimal. Principal component analysis (PCA) revealed convergent CHC profiles among the three tenebrionids with desert-adapted arthropods (Schistocerca gregaria and Pogonomyrmex barbatus) but divergent from mesophilic tenebrionids, supporting a water conservation strategy through long-chain n-alkane dominance, mono-methyl branching optimization, and poly-methylation suppression.Chemotaxonomic significance: Discriminant analysis based on 11 diagnostic CHC markers (Wilks'λ = 0, P < 0.001) achieved perfect species discrimination. Clustering patterns aligned with a concatenated COI-28S phylogeny (BPP = 1.00), confirming species-specific CHC signatures. Heatmap analysis demonstrated higher intraspecific CHC homogeneity than interspecific variability, validating their role as a complementary tool for morphological taxonomy. 【Conclusion】This study delineates xeromorphic CHC adaptation patterns in desert tenebrionids and establishes CHCs as robust biomarkers for sympatric species delimitation, advancing our understanding of insect adaptive evolution in extreme arid environments.

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