Filogeografia molecular de >i<Thyrinteina arnobia>/i< (Lepidoptera: Geometridae) e >i<Gonipterus>/i< spp. (Coleoptera: Curculionidae) no Brasil

Abstract

Molecular phylogeography of Thyrinteina arnobia (Lepidoptera: Geometridae) and Gonipterus spp. (Coleoptera: Curculionidae) in BrazilThe introduction of eucalyptus (Eucalyptus spp.) in the Brazilian territory and its territorial expansion enhanced the development of native Myrtaceae pests and created conditions of establishment for exotic pests introduced by man, as are the cases of the native pest Thyrinteina arnobia and the cryptic and exotic species Gonipterus platensis and G. pulverulentus, respectively. Today, these species are important defoliating pests of eucalyptus in Brazil. The relationship between eucalyptus and these pest species has persisted for several decades, leading us to ask about the current genetic and demographic structuring of these species in Brazil. Therefore, this work's objectives were: (i) to study the diversity, genetic structure, and demography of T. arnobia and Gonipterus spp. in Brazil. In addition (ii) to realize the molecular identifications of Gonipterus spp. and build species-specific molecular markers for quick and accurate identification of two Gonipterus species present in Brazil. For this, a fragment of the mitochondrial DNA was sequenced, specifically a fragment of the cytochrome oxidase gene and subunit I (COI), from the collected specimens. The results of diversity and genetic structure showed that T. arnobia and G. platensis populations have moderate genetic diversity and high structure by geographic region, mainly in T. arnobia, where populations in the Northeast of Brazil have high rates of molecular variance to the populations of the Center-South Region. The species G. pulverulentus did not present genetic diversity and was not included in the population analyses. T. arnobia and G. platensis are not demographic expanding/retracting. Still, they are in spatial expansion in Brazil. The specific marker developed for identifying G. platensis and G. pulverulentus was based on the use of species-specific primers and successfully allowed the identification of these cryptic species through a multiplex PCR and subsequent visualization of the results on an agarose gel. The current distribution of G. pulverulentus is restricted to the South of the country, while G. platensis is widely distributed in the Brazilian regions.