Maupiti is a small island west of Tahiti in French Polynesia. Its size and topography makes this island a choice ecological studies site. I will study flies (Diptera) in three localities for two weeks for comparison and analysis; watermelon patches, Morinda citrofolia plantation, and a natural habitat. I expect a correlation between plant diversity and flies diversity and expect to describe new species as many endemics species will be encountered. The outcome will be acomplete survey of Diptera diversity, relating the interaction of invasive and vulnerability of the local and endemic species.