DEVELOPMENT OF A PROTOCOL BASED ON MOLECULAR TECHNIQUES IN ORDER TO IDENTIFY NATIVE PREDATORS EATING THE BOX TREE MOTH CYDALIMA PERSPECTALIS, IN FRANCE

The box tree moth, Cydalima perspectalis (Walker, 1859), is a species of moth from Asia, belonging to the family Crambidae, that invaded Europe in 2007. Its rapid expansion and negative effects on boxwood (Buxus sempervirens), in the field as in parks and gardens, make it an invasive exotic species. In order to control this pest, biological control methods based on the use of Bacillus thuringiensis var. kurstaki are used nowadays, but this method is not specific enough and phenomena of resistance may appear. The search for alternative methods, such as the use of beneficial macro-organisms, is therefore essential. The objective of this study with the project SaveBuxus is to develop a protocol that allows to identify native predators which have eaten the box tree moth in situ, thanks to molecular analyses. In this context, collects of insects and spiders present in natural boxwood forest, in several sites with different environmental conditions, were carried out by beating method. The individuals collected were morphologically identified, and their digestive tracts were dissected. A molecular technique was then developed, starting with the molecular characterization of the pest for the barcode coI DNA fragment, as well as a wide variety of potential predators, in order to define strictly specific C. perspectalis primers for amplification. We then tested the presence of DNA of the box tree moth in the digestive tract of collected individuals. Our results demonstrate that several individuals belonging to three different species collected were tested positive for the pest’s DNA. The perspectives of this work are to perfect the method, and to continue surveys and collects in the field, to verify the natural adaptation of new predators to the box tree moth in situ. At the same time, this would allow us to consider a biological control based on the best identified predator.