Halteres

This is a blip that I have been meaning to post for a long time, so finally I can cross it off my list.

Halteres are the small club like structures found on all true flies, just behind the single pair of wings. I have chosen a crane fly for this demonstration as the halteres are much larger and more visible, but if you examine any fly up close, you will find these structures, including hoverflies.

The halteres are the fly's balancing organs. Some say that they evolved from the rear pair of wings over eons of time, but other scientists say that there is no evidence to back up this theory. The halteres beat in antiphase to the wings, acting as dampers to the wing vibrations, giving the fly a smoother ride.

But, there is a lot more going on than just a damping system. The fly's brain controls the haltares to perform the lightning fast changes in direction rather than changing the wing beat pattern.

Sensor receptors at the base of the haltares also send gyroscopic information back to the brain, a bit like out inner ear, providing orientation information like an airplanes gyroscope.

An added bonus to this blip is the tiny parasitic fly, feeding off the first segment of the abdomen. I did not notice this until the image was on screen.

Dave