My training course took place in the Unit of Forest Zoology of the National Institute for Agricultural Research (INRA).This laboratory studies the biology of insect populations expanding with global warming or newly introduced in Europe. One of themes of unit research is to finalize methods of DNA barcoding to identify invasive insect species. Nowadays, biological invasions occur regularly, but the human beings amplify this phenomenon, which becomes a major factor in the loss of biodiversity. The invasive insect Agrilus planipennis provokes heavy damages in the ash trees that it colonizes. The larva forms galleries under the bark of the ash trees which blocks the transport of water and nutriments. The tree decays in two years. This insect is not still present in France and plant controls during the imports must be realized to avoid its introduction. It is difficult to differentiate native Agrilus from Agrilus planipennis. To facilitate the identification of these Agrilus, I have developed a genetic method called barcoding to identify them. To obtain a genetic barcode for the species, it is necessary to extract DNA, to amplify a part of a mitochondrial gene called COI (Cytochrome Oxydase subunit I ) and to sequence the amplification product. During my training, I worked with nineteen specimens of Agrilus. I optimized the conditions of amplification and I managed to amplify the sequences of nine specimens. For the continuation of the project, these sequences will be used to design new primers which will allow to amplify all the species of Agrilus.