Population structure and colonization of Bactrocera dorsalis (Diptera: Tephritidae) in China, inferred from mtDNA COI sequences

Abstract

The oriental fruit fly, Bactrocera dorsalis, is a serious pest of fruits and vegetables in South‐east Asia, and, because of quarantine restrictions, impedes international trade and economic development in the region. Revealing genetic variation in oriental fruit fly populations will provide a better understanding of the colonization process and facilitate the quarantine and management of this species. The genetic structure in 15 populations of oriental fruit fly from southern China, Laos and Myanmar in South‐east Asia was examined with a 640‐bp sequence of the mitochondrial cytochrome oxidase subunit I (COI) gene. The highest levels of genetic diversity were found in Laos and Myanmar. Low to medium levels of genetic differentiation (FST ≤ 0.134) were observed among populations. Pooled populations from mainland China differed from those in Laos and Myanmar (FST = 0.024). Genetic structure across the region did not follow the isolation‐by‐distance model. The high genetic diversity observed in Laos and Myanmar supports the South‐east Asian origin of B. dorsalis. High genetic diversity and significant differentiation between some populations within mainland China indicate B. dorsalis populations have been established in the region for an extended period of time. High levels of genetic diversity observed among the five populations from Hainan Island and similarity between the Island and Chinese mainland populations indicate that B. dorsalis was introduced to Hainan from the mainland and has been on the island for many years. High genetic diversity in the recently established population in Shanghai (Pudong) suggests multiple introductions or a larger number of founders.

Genetic diversity and population structure in Bactrocera correcta (Diptera: Tephritidae) inferred from mtDNA cox1 and microsatellite markers

“…The A + T content was 63% (28.8% A and 34.2% T), higher than the G + C content (16.5% G and 20.5% C). This nucleotide composition is similar to B. dorsalis 26 and B. cucurbitae 27. Of the 600 nucleotide positions, 62 variable positions were observed (10.33%), including 19 singleton variable positions and 43 parsimony informative positions.…”

“…In contrast, microsatellites (SSRs) are nuclear, bi-parentally inherited, highly polymorphic and easy to isolate, making them particularly informative in the study of contemporary biological invasions1622. Thus, these two sets of molecular markers are extensively used to study the population genetic structure of insect pests202324, including Bactrocera fruit fly species16252627.…”

Global distribution and invasion pattern of oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae)

“…Based on ecological and molecular data, it is generally accepted that the native region range of B. dorsalis was Southeast Asia (Aketarawong et al, ; Choudhary, Naaz, Prabhakar, & Moanaro., ; Li et al, ; Shi, Kerdelhue, & Ye, ) or southern East China (Wan, Nardi, Zhang, & Liu, ) from where it invaded more countries. Over the last century, B. dorsalis spread from southern East China or Southeast Asia to other places of Asia, Africa and the Americas, a pathway that has been well supported by previous research (Aketarawong et al, ; Wan et al, ).…”

“…For example, B. dorsalis has been reported in Hawaii (1945), Guam (1947), Florida (1960) and California (1960) in the United States, as well as in Suriname (1975) in South America (Aketarawong et al, ; Pemberton, ; White & Elson‐Harris, ). Bactrocera dorsalis has invaded most provinces in southern China (such as Hainan, Guangxi, Yunnan, Guizhou, Fujian and Guangdong) and is expanding into northward there (such as Jiangsu, Zhejiang and Shanghai) (Chen, Cai, Zhang, & Sun, ; Li, Wu, Chen, Wu, & Li, ; Liang, Chen, Yang, Huang, & Ji, ). Although there have been many reports of new invasions of B. dorsalis around the world, the global pattern of the B. dorsalis invasion and spread is still poorly understood.…”

Historical perspective on the synonymization of the four major pest species belonging to the Bactrocera dorsalis species complex (Diptera, Tephritidae)

“…Closely linked in pest status with Bactrocera dorsalis are the now synonymized species Bactrocera papayae Drew & Hancock, Bactrocera philippinensis Drew & Hancock and Bactrocera invadens Drew, Tsuruta & White. Bactrocera dorsalis is known to cause devastating losses in fruit commodities, especially in the Asia-Pacific and Africa regions (Kawasaki et al 1991, Ye 2001, Verghese et al 2004, Clarke et al 2005, De Meyer et al 2010, Khamis et al 2012, Li et al 2012). …”