Drosophila hydei is described as a "true- fly "it belongs to the order Diptera (Pallister 1954). Like all other species of this order, each D. hydei has only one pair of wings while insects of other orders have either no wings or two pairs (Pallister 1954). The second pair of wings of D. hydei is replaced by "halteres-, a pair of little knobs mounted on slender stalks approximately where the second pair of wings would be (Pallister 1954). These structures are believed to be the modified wings that, along with the pair of true wings, distinguish the Diptera from other insects (Pallister 1954).
D. hydei is commonly found in open habitats, such as open slopes, gardens and orchards where food is plentiful (J. Skillcorn, Jan. 25, 2003, electronic communication). Usually, the period from June to August is when they are most abundant (J. Skillcorn, Jan. 25, 2003, electronic communication). They feed on decaying organic matter and, in turn, is a food source for larger organisms such as frogs (J. Skillcorn, Jan. 25, 2003, electronic communication).The life of an adult D. hydei is intimately related to various abiotic factors. Sunlight, for instance, is vital for a D. hydei because its food source is organic matter requiring sunlight to grow. D. hydei cannot grow in severely cold climate, yet an extended length of time in temperature in the high 40°C may prove fatal to the insect and their larvae (Shellie and Mangan 2000). For this reason are fruits heated to this temperature or immerse in hot water in order to get rid of all the insect pests (Shellie and Mangan 2000).
In addition to factors that affect the adult fly, there are factors that decide the fitness of D. hydei larvae and their pupation behavior. D. hydei pupate directly in their food source, decaying plant or fungi matter containing the yeasts and bacteria on which they feed (Reuven 1999). However, the exact pupation behavior, such as the depth under the surface of the food medium at which they pupate, is different from individual to individual under varying environmental factors (Hodge and Caslaw 1998).