Study On The Morphological And Molecular Identification Of Antlion Larvae(Neuroptera:Myrmeleontidae)

This thesis has two subjects:(1)Morphological identification of antion larvae.(2)Molecular identification of antion larvae.The research advance on larval morphology and biology of Myrmeleontudae(Neuroptera:Myrmeleontidae)was summarized.The larval morphological characters of antion larvae were studied and the common morphological terms of larval antion were defined and annotated.The morphological identification of antion larvae was realized by raising the larvae to adults and then confirming their scientific name.This paper described 23 speices of larval antion which collected in China,belong to 8 genera of 5 tribes(Myrmeleontini,Myrmecaelurini,Nemoleontini,Nesoleontini,Acanthaclisini)of 1 subfamily(Myrmeleontinae).The keys to tribes,genera and speices were provided.The overseas antion larvae were studied in the Natural History Museum,London.88 specimens of antion larvae collected from Africa,Europe,Asia,North America were examined.All the specimens were conserved in the Natural History Museum,London.16 speices of them have been identified,belong to 2 subfamilies(Myrmeleontinae,Palparinae)and 5 tribes(Myrmeleontini,Myrmecaelurini,Nemoleontini,Acanthaclisini and Palparini).The larvae of these 16 speices were described.398 images of all the domestic and overseas 39 speices were provided in this paper.To shorten the time of identification and to overcome the identifying difficulties by morphological confusion of some larvae,a molecular identifying method using DNA to the antion larvae was studied.The mtDNA COI of 10 speices of adult antion were sequenced in this research.105 COI sequences of 29 species of adult antion from BOLD were downloaded.The genetic distance between samples based on the parameter(K2P)model were calculated.The results show that the max intraspecific genetic distance of 74%species is smaller than 0.02,the max intraspecific genetic distance of 26%species is between 0.02-0.03,the max intraspecific genetic distance of 26%species is between 0.03-0.04.Interspecific genetic distance of species belonged to different subfamily is 0.261,the min interspecific genetic distance of species belonged to one genus is 0.072.So 0.03 is the criteria of Myrmeleontidae species in this experiment.The COI of 9 morphological types of antion larvae were sequenced,the genetic distance between these larvae and all checking adults was calculated.The results show that the genetic distances between 7 morphological types of antion larvae of them and their adults are 0.00-0.02.Based on these results the 7 morphological types of antion larvae got their species name.The 2 morphological types of antion larvae of them have not got their species name because the genetic distances between these 2 morphological types of antion larvae and all checking adults are not smaller than 0.03.The comparing results of molecular identification and morphological identification for these 9 species of antion larvae indicated the molecular identification based on COI has a high credibility for some antion larvae.Accumulation of molecular data is the key to researching molecular identification of antlion larvae.In order to the accumulation of molecular data of Myrmeleontidae,the mitochondrial genome of Myrmeleon immanis was sequenced.It is 15802 bp,includes 13 PCGs,2 rRNA,22 tRNA and a control region(968 bp).The problems and prospects of this study were summarized.