D. melanogaster exhibits complete metamorphism, meaning the life cycle includes an: egg, larval (worm-like) form, pupa and finally emergence (eclosure) as a flying adult. This is the same as the well-known metamorphosis of butterflies and many other insects. The larval stage has three instars, or molts. These are growing stages, and as they grow over time, they molt. (also known as an imago)

Newly hatched larva

Sex Combs on foreleg Male Morphological Characteristics: slightly smaller than female darker, rounder abdomen than female dark bristles on the upper portion of the forelegs (sex combs) males have a cluster of spiky hairs (claspers) surrounding the anus and genitals used to attach to the female during mating

Female Morphological Characteristics Slightly larger than the male Light-colored, slightly pointed abdomens No sex combs

Females become receptive to courting males at about 8-12 hours after emergence from the pupa. Males perform a sequence of five behavioral patterns to court females. First, males orient themselves while playing a courtship song by horizontally extending and vibrating their wings. Soon after, the male positions itself at the rear of the female's abdomen in a low posture to tap and lick the female genitalia. Finally, the male curls its abdomen, and attempts copulation. Females can reject males by moving away and extruding their ovipositor. The average duration of successful copulation is 30 minutes, during which males transfer a few hundred very long (1.76mm!) sperm cells in seminal fluid to the female. To put that in perspective, human sperm is.045 mm (or 45 µ) long. Females store the sperm, which may need to compete with other males' stored sperm to fertilize eggs.

This year you will have the following types of flies available to you: Wild type White eyes Vestigial type Sepia eyes

Kingdom : Animalia Phylum : Arthropoda Class : Insecta Order : Diptera Family : Drosophilidae Genus: Drosophila Subgenus : Sophophora Species: D. melanogaster Chromosome number : 2n=8