Nearly half of the biodiversity on Earth is represented by phytophagous insects and flowering plants. Since Ehrlich&Raven(1964), there is a great interest for understanding the evolutionary forces which drive the co-diversification of these two groups. Here we focus on Gracillariidae, larvae is internal feeder of leaving leaves, this interaction has been previously characterized by a high degree of specialization.

Data of host-plants have been gathered, we have completed CO1 barcodes of French Guiana Gracillaridae to delimit Barcode species, finally a large maximum likelihood phylogenetic analysis has been performed based on CO1, H3 and 28S genes.

CO1 barcodes analysis indicate that Gracillariidae fauna in tropics present an important spatial turn-over between two sites (130 km) in French Guiana. Indicating a still poorly known fauna in this region. Phylogeny analysis and host-plant use reveals, as previous study, a high level of specificity with species mainly monophagous. It also reveals that pattern of host-plant were in majority composed of sister-species of Gracillariids which feed on closely related species. Just few host-shift between remote plant families could be related to sampling bias. Thus the main conclusion is that ecological speciation could potentially has played an important role in the diversification of this neotropical family.