Previous | Next

Actual Research

In walnut flies, combat between males goes through two distinct stages. The first is chasing/butting/wing-flicking. If neither opponent retreats after this, they progress to "boxing" -- the flies stand face to face, on their hind legs, spread their wings out to the side, and raise their forelegs straight up. They then tap their forelegs together. If a size difference is not immediately visible, they will edge closer and closer to each other, in an apparent attempt to determine which is larger, thus escalating to "the kiss."

Next: video clips of walnut flies performing these amazing behaviors!