The sex comb is a specialized structure present exclusively in the forelegs of
male flies. Location, size, and structure vary from species to species. An adult
Drosophila has 3 pairs of legs:
- Hindlegs: In adult males, the forelegs have a comblike structure with chitinized black teeth called the sex comb. It is present in the first tarsal segment of the forelegs of the males. It is absent in the females. The sex comb helps the male hold the female during copulation or mating.
- Glass slides
- Cover slip
- Male flies
- Dissecting microscope
- Etherize the flies and separate the males.
- Separate the forelegs using needles under the dissecting microscope.
- Put a drop of glycerine on the forelegs and place the cover slip on top.
- Search and observe the sex comb on the first tarsal segment.