As the name implies, the fruit flies lives primarily on plant material. The adults thrive on rotting plants, and fruits; while eggs are usually laid on unripened/slightly ripened fruit, so by the time the larva develop the fruit will have just started to rot, and they can use the fruit that the egg was laid on as their primary source of nutrition. Drosophila are considered major pests in some area of the world for this reason. (Demerec, 1950; Lutz, 1948; Wilson, October,1999)