Improving knowledge on thrips diversity and ecology in French greenhouses: inputs of barcoding approaches for a better pest management

Thrips are among the most important pests in greenhouses worldwide because of recurrent outbreaks of both native and invading species. Yet, the biodiversity, distribution and ecology of thrips taxa are still poorly documented. Reasons accounting for this situation are probably their small size, the high morphological similarity among taxa and their cryptic behaviour. In this work, we used cytochrome oxydase subunit I (COI), the ribosomal RNA sub-unit 28S and the internal transcribed spacer 2 (ITS2) for DNA barcoding to document the biodiversity of thrips taxa collected in Metropolitan France and neighbouring countries. Thrips were sampled in or around crops thanks to a large collaborative network including agronomic centers and producers. More than 500 specimens were collected, more than 180 being presented here. Detailed temporal surveys were also realized on some specific areas. For each different genotype sampled, morphological characterization was associated to the molecular data. We present here the first results and provide data that may prove relevant for the understanding of thrips populations dynamics and management: relative abundance of the various taxa within the season, on the crops or in the vicinity, evidence of sources of infestations, occurrence of taxa before and after insecticide spraying, etc.