2.4 Barcoding analysis based on COI
Bidirectional sequencing was employed to guarantee the precision of sequencing. We aligned the COI gene using the ClustalW program from MEGA 7.0 (Tamura et al., 2013) package for each order with default parameters (Zhou et al., 2010). The amino acid translation was conducted to ensure that no gaps or stop codons existed in the alignment. Totally, we obtained 1227 COI sequences from 189 species. Detailed information (locality data, habitat, altitude, collector, identifier, taxonomic classifications, habitus images and DNA barcode sequences etc.) for each voucher specimen was deposited to the Barcode of Life Data System (BOLD) at http://www.boldsystems.org (Ball et al., 2007), under the dataset project “XJDQD” (Process IDs: XJDQD001-18-XJDQD1275-18).