One Species of Drosophila Flies Turning Into Pests
Fruit flies have long been used for all types of studies. Many species exist, and only one has been identified as being a crop pest. Researchers from the University of California recently explained the similarities and crucial differences between this species and the others. They also expanded on the idea of why another close relative has the potential to become a pest, as well.
Drosophila flies are found around the globe, laying eggs on rotting fruit. The species called Drosophila suzukii, or spotted-wing drosophila, is named for the big black blotches on the male’s wings. This fly is able to penetrate the skin of fruit that is ripening, to lay eggs on the inside. Researchers were surprised at the finding that D. suzukii was a pest. Until now, scientists believed Drosophila only laid their eggs on rotting fruit.
This species of Drosophila appears to have originated in Asia, being reported in Hawaii during the 1980s. However, it wasn’t until 2008 that the flies were identified as a pest in North America. They appeared in orchards in Southern California at the same time, and then spread rapidly across the country. The physical characteristics that differ in D. suzukii include a pointed ovipositor with prominent bristles, in comparison with those of other flies’ ovipositors being smaller. A similar but smaller pattern of bristles is also seen on other species.
Researchers found that both D. suzukii and D. subpulchrella flies had the ability to penetrate the skin of raspberries and cherries and deposit eggs in them. D. suzukii flies also made holes in grape skins while the D. subpulchrella did not. Researchers noted that they will need to identify which of the Drosophila species are dangerous, and which are not, before facing the challenging job of controlling them.