关键词:  , 半翅目； 异翅亚目； 蛛缘蝽科； DNA条形码； COI； 物种界定

Abstract:  【Aim】 The aim of the study is to test the validity of DNA barcoding for the identification of broad-headed bugs (Hemiptera: Coreidae) from China. 【Methods】 The DNA barcode sequences of mitochondrial COI gene of 207 samples from 23 species of 13 genera of Alydidae from China were amplified, and 31 internal transcribed spacer 1 (ITS-1) sequences of three Leptocorisa species were amplified as auxiliary markers. The interspecific and intraspecific genetic distances (Kimura 2-parameter model, K2P) were calculated by MEGA 11 software. The species cluster analysis was performed using neighborjoining (NJ) method. The holotype networks were constructed using median joining network algorithm. 【Results】 Based on the DNA barcode sequences of mitochondrial COI, the mean intraspecific K2P distances of all the tested 23 species of Alydidae from China were below 2%, and the interspecific K2P distances ranged from 0.98% to 23.98%, with an average of 17.50%. Most species were separated from each other with a high bootstrap value. This COI barcode section could not distinguish between Leptocorisa chinensis and L. oratoria because of the partial COI haplotypes they shared. The ITS-1 sequences did distinguish the two species in the haplotype network analysis. 【Conclusion】 The DNA barcoding results from our data are congruent with most of the taxonomic units of the family Alydidae from China based on morphological characteristics. However, for extremely closely related species, mitochondrial data alone, especially COI barcode sequences, sometimes are insufficient for accurate species delimitation, and other DNA sequences or other types of data need to be introduced.

Key words:  Hemiptera, Heteroptera, Alydidae, DNA barcoding; COI, species delimitation