Résumé
The archipelago of Sao Tome and Principe is a major centre of endemism for vertebrates but, to date, arthropods remain poorly studied, with the exception of mosquitoes due to their medical and economic relevance. Previous studies, over 20 years old, recorded 26 species of mosquitoes for Sao Tome and 14 for Principe, of which six and two were endemic to each island respectively. We collected mosquito larvae and adults on both islands and found three species as a first record, putting the number of mosquito species collected at least once on Sao Tome at 29 and 15 for Principe. We compared the mosquito richness on Sao Tome and Principe islands to 71 other oceanic islands represented within 20 archipelagoes worldwide. We used the general dynamic model of oceanic island biogeography and the associated ATT(2) (for Area+Time+Time(2)) model to explain two different metrics: (i) the richness of the single-island endemics and (ii) the richness of archipelago endemics. We also included other island characteristics in our model, such as isolation and latitude. Our data compilation and comparative analyses revealed an overall low richness of endemic mosquitoes on islands, with the highest number of single-island endemics found on Sao Tome Island. As predicted, we found a positive relationship between our two richness metrics and the general dynamic model ATT(2), although the model with the area (A) alone also explained endemic richness. Isolation was also predictor of mosquito diversification.