2.0 LITERATURE REVIEW
2.1 Drosophila melanogaster
Drosophila melanogaster belongs to the Kingdom: Animalia, Phylum:Arthropoda, Class:
Insecta, Order: Diptera, Family: Drosophilidae, Genus: Drosophila, Subgenus: Sophophora, Species: melanogaster. The species is known generally as the common fruit fly or vinegar fly (Meigen, 1830).
Ashburner et al. (2005), in their various investigations about Drosophilids, discovered that Drosophila melanogaster undergoes complete metamorphosis (egg to larva to pupa and to adult), with a developmental period varying with temperature, as with many ectothermic species: its shortest developmental time (7 days), is achieved at 28˚C (82˚F), which increases to 11 days at higher temperature of 30˚C (86˚F) due to heat stress. Its lifespan is about 30 days at 29˚C (84˚F) and with a record of an increased lifespan of 3 months. Hirth (2010) also observed that diet such as cornmeal prolongs the lifespan of the fly, while diets with high quantities saccharides and cholesterol can reduce life expectancy. According to Meeta et al. (2008); Acurio et al. (2010); Penariol and Madi- Ravazzi (2013), Drosophilids especially D. melanogaster, D. simulans, D. malerkotliana are primarily found in environments disturbed by man, in open areas, or in degraded and urbanized environments which are characterized by a pronounced degree of environmental stress.