First occurrence of the pest Drosophila suzukii (Diptera: Drosophilidae) in the Comoros Archipelago (Western Indian Ocean)

Drosophila suzukii (Matsumura, 1931) is an Asian pest of grapes and other soft fruits that has invaded North America and Europe during the last decade. Here we report its recent occurrence on two islands of the Comoros archipelago in the Mozambique Channel, namely Mayotte and Ngazidja (Grande Comore), in April 2017 and November 2018, respectively. We also document its absence from other African islands in the Mozambique Channel and the Western Indian Ocean including Mayotte until 2013. Drosophila ashburneri Tsacas, 1984 is the only member of the suzukii species subgroup known from the Comoros, but it is morphologically distinct and likely distantly related to D. suzukii. Drosophila suzukii has likely been recently introduced to the Comoros archipelago, perhaps from La Reunion island where it first appeared in November 2013. On all of these tropical islands, D. suzukii was found in high-altitude habitats in agreement with its adaptation to cold environments. These results suggest the high susceptibility of highlands in eastern and southern Africa to be infested by this pest in the near future.