Molecular identification and demography of Gonipterus species (Coleoptera: Curculionidae) in Brazil

The curculionids-pests known as Eucalyptus snout beetles are part of a group of eight sibling species, native to Australia, called the “Gonipterus scutellatus complex.” The identification of the G. scutellatus species complex remained obscure for several years, same in places where this complex is invasive pests as in Brazil. Thus, the application of molecular markers can help in the species identification and contribute to inferring demographic parameters of these pests' invasive populations. Here, our objectives were: (i) identify the species of Gonipterus present in Brazil and infer their geographic distribution in the country; (ii) build species-specific molecular markers for Gonipterus species present in Brazil; and (iii) estimate the genetic diversity, demographic and population structure parameters of G. platensis in Brazil. We used Gonipterus individuals from 7 locations in Brazil. Subsequently, a fragment of the cytochrome c oxidase subunit I (COI) gene was sequenced, which served as the basis for the molecular identification and demography analyzes. The identification of the sibling species G. platensis and G. pulverulentus using specific primers revealed that G. pulverulentus is restricted to the South of Brazil, and G. platensis occurs in the South region, overlapping with G. pulverulentus, and Brazil's Southeast and Northeast. Furthermore, the population structure analysis of G. platensis revealed low genetic diversity within the country and spatial expansion, despite Brazilian populations are not in demographic expansion in the Brazilian territory.