Population genetic differentiation of the black locust gall midgeObolodiplosis robiniae(Haldeman) (Diptera: Cecidomyiidae): a North American pest invading Asia

Abstract

Obolodiplosis robiniae is native to North America and is an important introduced insect pest that forms leaf margin roll galls on species of genus Robinia (Fabaceae) in China. It was first detected in China in 2004, but subsequently spread and provoked local outbreaks. An analysis of a 676-bp sequence of the mitochondrial DNA cytochrome oxidase subunit I was conducted in 560 individuals from 28 populations, in order to (1) assess population genetic structuring and (2) explore possible explanations for the rapid spread and invasion success of O. robiniae. Yet, only four haplotypes were identified and the nucleotide diversity was low (π = 0.00005) and among the 560 specimens studied, only ten showed haplotypic variation involving no more than three substitutions. The result showed a low degree of genetic diversity among populations of the successful invasive gall midge, which suggested that the pest experienced a severe genetic bottleneck and a loss of genetic diversity after its introduction. The successful establishment and spread of O. robiniae in China is attributed to the wide distribution of its host plant, thus allowing ample opportunities for gene flow in the pest species, and to the advantageous life history characteristics of O. robiniae.

Low genetic diversity but strong population structure reflects multiple introductions of western flower thrips (Thysanoptera: Thripidae) into China followed by human‐mediated spread

“…Nevertheless, genetic diversity in WFT based on microsatellite markers and mitochondrial DNA was higher than in other invasive species introduced to China from America, such as the fall webworm Hyphantria cunea (Cao, Wei, et al., ), red turpentine beetle Dendroctonus valens (Cai, Cheng, Xu, Duan, & Kirkendall, ) and black locust gall midge Obolodiplosis robiniae (Shang, Yao, Huai, & Zhao, ). For instance, only one mitochondrial haplotype and an allelic richness of 2.92 were observed in 24 populations of fall webworm in China, in contrast to 12 haplotypes and an allelic richness of 6.29 in two populations from North America.…”

Genetic Variation May Have Promoted the Successful Colonization of the Invasive Gall Midge, Obolodiplosis robiniae, in China

“…Our results indicate significant differences in genetic diversity within the Chinese populations, as well as between the native and invasive populations. Shang et al (2015b) detected a relatively low level of genetic diversity among Chinese O. robiniae populations using a COI marker. This discrepancy suggests that COI markers may be less suitable than microsatellite DNA markers for population analyses of a new invasive species, such as Chinese O. robiniae, as is the case with another invasive cecidomyiid, Procontarinia mangiferae (Amouroux et al, 2013).…”

“…Previously, Shang et al (2015b) investigated the genetic variation among Chinese O. robiniae populations using a partial mitochondrial DNA cytochrome c oxidase subunit I (COI) sequence marker. However, only 10 individuals exhibiting haplotypic variation and a mere four haplotypes were detected in 560 O. robiniae samples.…”

Supplementary material 1 from: Mally R, Ward SF, Trombik J, Buszko J, Medzihorský V, Liebhold AM (2021) Non-native plant drives the spatial dynamics of its herbivores: the case of black locust (Robinia pseudoacacia) in Europe. NeoBiota 69: 155-175. https://doi.org/10.3897/neobiota.69.71949

“…Obolodiplosis develops through three generations per year in the Czech Republic, and in up to four generations in more southern regions such as Italy, Hungary and Serbia (Skuhravá et al 2007;Mihajlović et al 2008;Duso et al 2011). For China, however, up to six generations per year have been reported (Shang et al 2015). The capacity for this species to develop through multiple generations likely facilitates rapid population growth (Fahrner and Aukema 2018).…”

“…These were sourced from GBIF (https://www.gbif.org), EPPO (https://gd.eppo.int), CABI (https://www. cabi.org/ISC), Davis and De Prins (2011) and Shang et al (2015). These global records were not used for analysis of spread rates.…”