Species Delimitation Of The Predatory Insects Around Beijing And Tianjin With DNA Barcoding

In this study,the sequencing of the mitochondrial cytochrome oxidase I(COI)barcode region from predatory natural enemy insects around Beijing and Tianjin are reported.In total,5890 sequences of COI fragment which belong to twelve orders(e.g.,Diptera,Hymenoptera,Neuroptera)were obtained.One DNA sequence database,an annotated collection of all above sequences,was constructed.Furthermore,the final data set of 2068 COI sequences was analyzed through Neighbor-Joiningtree-reconstruction method,and by applying different models(ABGD,j MOTU and GMYC)to partition the sequences according to the pattern of genetic variation.The detailed results are as follows:1.1086 COI sequences of Diptera were analyzed: 217 putative molecular species were identified by ABGD,218 putative molecular species were distinguished by j MOTU method,and 78 putative molecular species were recognized by GMYC method.2.530 COI sequences of Hymenoptera were analyzed: 187 putative molecular species were identified by ABGD,193 putative molecular species were distinguished by j MOTU method,and 60 putative molecular species were recognized by GMYC method.3.171 COI sequences of Trichoptera were analyzed: 27 putative molecular species were identified by ABGD,27 putative molecular species were distinguished by j MOTU method,and 14 putative molecular species were recognized by GMYC method.4.70 COI sequences of Orthoptera were analyzed: 22 putative molecular species were identified by ABGD,23 putative molecular species were distinguished by j MOTU method,and 12 putative molecular species were recognized by GMYC method.5.68 COI sequences of Hemiptera were analyzed: 31 putative molecular species were identified by ABGD,36 putative molecular species were distinguished by j MOTU method,and 29 putative molecular species were recognized by GMYC method.6.56 COI sequences of Neuroptera were analyzed: 13 putative molecular species were identified by ABGD,14 putative molecular species were distinguished by j MOTU method,and 10 putative molecular species were recognized by GMYC method.7.28 COI sequences of Mantodea were analyzed: 5 putative molecular species were identified by ABGD,5 putative molecular species were distinguished by j MOTU method,and 6 putative molecular species were recognized by GMYC method.8.23 COI sequences of Dermaptera were analyzed: 8 putative molecular species were identified by ABGD,8 putative molecular species were distinguished by j MOTU method,and 7 putative molecular species were recognized by GMYC method.9.15 COI sequences of Ephemeroptera were analyzed: 4 putative molecular species were identified by ABGD,4 putative molecular species were distinguished by j MOTU method,and 4 putative molecular species were recognized by GMYC method.10.10 COI sequences of Raphidioptera were analyzed: 3 putative molecular species were identified by ABGD,3 putative molecular species were distinguished by j MOTU method,and 4 putative molecular species were recognized by GMYC method.11.7 COI sequences of Blattaria were analyzed: 4 putative molecular species were identified by ABGD,5 putative molecular species were distinguished by j MOTU method,and 4 putative molecular species were recognized by GMYC method.12.4 COI sequences of Odonata were analyzed: 2 putative molecular species were identified by ABGD,2 putative molecular species were distinguished by j MOTU method,and 3 putative molecular species were recognized by GMYC method.The results of each method are not completely consistent,and the results showed that ABGD and j MOTU are able to define species quickly,while GMYC method requires higher computational power,operator's experience and background knowledge.GMYC is time-cosuming when data is large,and it is possible to underestimate species diversity.In addition,the COI fragment was used as molecular marker to analyze the genetic differentiation and the phylogeographical structure of Episyrphus balteatus in Yanshan-Taihang Mountains Area.The results showed that the Wuling Mountain population had the highest genetic diversity,and there was no significant correlation between the genetic distance and geographic distance.The current study estimated the divergence time of populations,which was in the Pleistocene(0.02-0.94Mya).We supposed that the reasons of differentiation of E.balteatus in Yanshan-Taihang Mountains Area are the repeated changes of Quaternary glacial climate,and the Wuling Mountain should be one of the important refuges for E.balteatus in the last ice age of the Quaternary.