Drosophila virilis is a species of fruit fly with a worldwide distribution (probably due to human movements), and was one of 12 fruit fly genomes sequenced for a large comparative study. The males have bright red gonads that can be seen through the cuticle. The life cycle of D. virilis is longer than that of D. melanogaster, in part owing to its larger body size; adult D. virilis are approximately twice the size of D. melanogaster. Source: Wikipedia (en)