Unveiling biogeographical patterns in the worldwide distributed Ceratitis capitata (medfly) using population genomics and microbiome composition

Abstract

Invasive species are among the most important, growing threats to food security and agricultural systems. The Mediterranean medfly, Ceratitis capitata, is one of the most damaging representatives of a group of rapidly expanding species in the family Tephritidae, due to their wide host range and high invasiveness potential. Here, we used restriction site‐associated DNA sequencing (RADseq) to investigate the population genomic structure and phylogeographical history of medflies collected from six sampling sites, including Africa (South Africa), the Mediterranean (Spain, Greece), Latin America (Guatemala, Brazil) and Australia. A total of 1907 single nucleotide polymorphisms (SNPs) were used to identify two genetic clusters separating native and introduced ranges, consistent with previous findings. In the introduced range, all individuals were assigned to one genetic cluster except for those in Brazil, which showed introgression of an additional genetic cluster that also appeared in South Africa, and which could not be previously identified using microsatellite markers. Moreover, we assessed the microbial composition variations in medfly populations from selected sampling sites using amplicon sequencing of the 16S ribosomal RNA (V4 region). Microbiome composition and structure were highly similar across geographical regions and host plants, and only the Brazilian specimens showed increased diversity levels and a unique composition of its microbiome compared to other sampling sites. The unique SNP patterns and microbiome features in the Brazilian specimens could point to a direct migration route from Africa with subsequent adaptation of the microbiota to the specific conditions present in Brazil. These findings significantly improve our understanding of the evolutionary history of the global medfly invasions and their adaptation to newly colonized environments.

Gut bacterial population and community dynamics following adult emergence in pest tephritid fruit flies

“…4 and 5 ). Representatives of the Enterobacteriaceae have been documented in wild and captive medfly microbiomes globally 29 , 54 – 58 . Members of the Enterobacteriaceae, like Klebsiella and Enterobacter , are likely physiologically important components of the adult medfly gut microbiome 14 .…”

“…Specifically, the amount of variation in specific isolates and strains, and how that might impact fly performance is unknown. Given its status as a global pest and the fact that there are apparent compositional differences in the medfly microbiome 58 , 61 , this is a major deficiency in our understanding of strain diversity in this system. For instance, our results and others 52 indicate some reconfiguration of some degree across host development, but we do not know if new strains are entering the system, or whether it is the same strain that was once suppressed is reestablishing dominance.…”

Macaronesian Plants as Promising Biopesticides against the Crop Pest Ceratitis capitata

“…Ceratitis capitata , the Mediterranean fruit fly, also known as medfly, is a polyphagous species that has spread from its supposed origin in Africa to several regions of the world and is considered a major problem for the fruit market since it is able to infest the fruits of over 300 species of plants, causing significant economic losses to agricultural communities [ 1 , 2 , 3 , 4 ]. Ceratitis capitata can act as a potential vector for Erwinia amylovora , which causes fire blight in apple and pear orchards [ 5 ].…”

Biosecurity and Management Strategies for Economically Important Exotic Tephritid Fruit Fly Species in Australia

“…Here, we aim to review Australia's capacity for preventing and managing an incursion of exotic tephritid fruit flies. Observations of the history of incursions and subsequent eradication attempts, such as the incursion of OFF into Africa [14,20] or medfly (Mediterranean fruit fly, Ceratitis capitata (Wiedemann)) into almost every continent [21,22], can assist in developing best practice management strategies for control and damage mitigation. We provide a summary of national and international tephritid fruit fly incursion management practices, a summary of the history of economically damaging fruit flies in Australia and an outline of the potential of an incursion into Australia by exotic fruit fly.…”