| Bactrocera are important fruit and vegetable pests, have large population, one of the main factors restricting the development of Hainan agriculture. The traditional method for identification based on morphological characters that are limited by several facters. First of all, some close-related species are very similar by morphology. Secondly, most of the specimens need to be identified are larvae or eggs, usually impossible to be identified.Thirdly, the specimens need to be identified are not completein some case.In the agricultural production, farmers often failed to take effective measures to prevent crops from these pests dur to difficulties to identify the speices. Besides, all species of genus of Bactrocera are listed in the checklist of quarantine pests of China,it is urgent to develop a method for identifying Bactrocera species quickly and accurately. In this research,specimens of Bactrocera species were collected from all over Hainan Island and identified based on morphological characters, and DNA barcodes of some species were sequenced.The main results are as following:1. Three different kinds of lure including methyl eugenol (ME), cuelure (CUE) and protein bait (PB) were used for collecting in 21 sites located in 11 cities such as Haikou,Danzhou, Sanya, etc. Totally 7346 specimens of 9 species were collected, including one new record species of China, Bactrocera pedestris (Bezzi), and two new record species of Hainan Province, B. correcta (Bezzi) and B. thailandica Drew&Hancock.2. Morphological characters of 19 Bactrocera species werecompared, including B.abbreviata,B. bivittata,B. caudate, B. cilifera, B. correcta,B. cucurbitae,B. diaphora,B.dorsalis, B. flavoscutellata, B. hochii, B. latifrons, B. nigrifemorata, B. pictipennis,B.pedestris, B. rubigina, B. scutellata, B. tau, B. thailandica, B. wuzhishana. Through checking the specimens form field collected and loans from the collection of Hainan Entry-Exit Inpection and Quarentine Bureau. Photoes of 18 Bactrocera species were took using Microscope connected with digital camera, and key to species were also established.3. Using partial fragment of cytochrome oxidase I (COI) as barcode gene, DNA barcodes of 9 species were sequenced. DNA barcodes of B. pedestris and B. bivittata were sequenced for the first time.4. Genetic distances in and between species were anaylized based on our sequences together with related sequences downloaded from Barcode of Life Database (BOLD).Barcoding gap for distinguishing Hainan Bactrocera species were discovered. Besides, the phylogenetic tree of the genus Bactrocera species of Hainnan that were also reconstructed based on COI gene using Neighbour-joining method. Specimens for the same species are well clustered on the NJ phylogenetic tree.5. Haplotype analysis was performed for the species B. dorsalis from 4 geographic populations including Haikou, Ding'an, Chengmai and Wanning. A total of 23 haploid types were identified .Population diversity of Haplotype (Hd) is 1.00000 for Haikou,Chengmai,and Wanning Populations While 0.83333 for Ding'an populationAs a conclude, our study generated and evaluated the DNA barcodes of Batrocera spp.of Hainan Island, proved DNA barcoding can be used to identify Batrocera spp. of Hainan rapidly and accurately which could satisfy the needs of agricultural production and quarantine. That will reduce the risk of the bio-invasion of Bactrocera spp. and ensure the safe production of fruits and vegetablesin Hainan Island. |
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