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An integrative morphological and molecular diagnostics for Typhlodromus pyri (Acari: Phytoseiidae)
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Contact: tixier@supagro.inra.fr, okassa@supag-ro.inra.fr, kreiter@supagro.inra.fr. Phytoseiidae species are predators used in biological control programmes to limit mite pests out-breaks in the world. Specific diagnostic is thus very important to ensure the success of pest management. This study aims to determine the species status of populations within the main species in vineyards and orchards: Typhlodromus (Typhlodromus) pyri, considering four molecular markers (COI, Cytb mtDNAs, 12SrRNA, ITSS) and 34 morphometrical characters. With the three mitochondrial DNA fragments considered, unexpected high genetic distances were observed between two groups, whereas both nuclear DNA and morphological analyses did not show such distinction. Furthermore, the GYMC and the 4 x rule tests emphasised the existence of a single species. Similarly, cross-breeding experiments between specimens of the two groups showed no reproductive incompatibility. Therefore, despite the great intraspecific variation emphasised by the three mtDNA markers, we conclude that all the specimens considered belong to the same species. The present study clearly underlines the difficulty to conclude on species status using only mt markers and genetic distances, and stresses the necessity to apply multiple approaches for species definition. It also shows the confidence of the morphology for delineating this species.
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