Genetic diversity and ecological modelling of the invasive gall wasp Ophelimus maskelli (Hymenoptera: Eulophidae) across native and invaded ranges
Abstract
Biological invasions represent an increasing threat to biodiversity, forest production, and the stability of managed ecosystems. This thesis investigates the invasion risk, evolutionary history, and phylogeographic structure associated with Ophelimus maskelli, an Australian gall-inducing wasp related to damage in Eucalyptus species. The study combines potential distribution modelling, molecular, phylogenetic, and phylogeographic analyses to understand the processes that favor the dispersal, establishment, and identification of invasive lineages. Ecological modelling, based on MaxEnt and CLIMEX, evaluated the climatic suitability of O. maskelli under current and future conditions, with emphasis on the risk to Eucalyptus plantations in Brazil. The results indicate climatically favorable areas for the species and highlight differences between correlative models and climate-matching approaches, allowing a broader assessment of its establishment potential. The integration of climatic distribution, Eucalyptus cultivation areas, and possible dispersal routes contributes to the identification of priority regions for phytosanitary monitoring. Subsequently, sequences of the mitochondrial COI gene were used to reconstruct evolutionary relationships and validate diagnostic regions with potential application in molecular identification. The molecular analyses showed that the Ophelimus complex includes genetically distinct lineages, some of which may have been previously misidentified as O. maskelli, reinforcing the importance of molecular approaches to reduce taxonomic identification errors in occurrence records. This thesis demonstrates that the combination of ecological modelling, phylogeography, and DNA barcoding provides a robust framework for understanding biological invasions in insects associated with planted forests, while also supporting strategies for surveillance, management, and prevention of new introductions. Keywords: Ophelimus maskelli; Biological invasion; Ecological modelling; Eucalyptus; Phylogeography; DNA barcoding.