Celebrity flies

Continuing with the topical apple subject, I have been leaving damaged and rotten apples on the soil of a large pot. The place now is heaving with tiny fruit flies of the genus Drosophila - possibly the most famous and best known fly in biology, D. melanogaster. It is difficult to give an idea of how much research has been carried out using this fly but a quick search on the Google Scholar academic search engine yielded today under 3,000 hits on the common earwig, while D. melanogaster had 324,000 entries. Since the beginning of last century, experiments on fruit flies have generated much of the basic knowledge of genetics and evolution, and their genome sequence was published in 2000, before the human genome. Among the many reasons they have become such a popular model organism is that they are ubiquitous, easy to keep (who doesn't have fruit flies around the compost heap or fruit bowl?) and reproduce rapidly producing many eggs.
Much research has been carried out on fruit flies mating behaviour and the influence of genes on it. Despite their tiny size fruit flies can be easily watched performing their mating rituals on top of the rotting apples. Males are smaller and with a larger dark patch at the end of their abdomen. Females have a more stripy, and often distended abdomen.
According to Marla Sokolowski:

It might come as a surprise to some that D. melanogaster shows many exquisitely performed and complex patterns of behaviour. For example, the male fly shows courtship behaviour that is full of sensory stimuli and that requires the female to hear his song, feel his taps and licks, smell his odours and visually evaluate his stature...

As a primer, this figure (also from Sokolowski, 2001) illustrates the main steps of the fruit fly mating behaviour. Male 'song' is produced by wing vibration while keeping the wing tipped forward.

Check out the Drosophila melanogaster Wikipedia page for more info.