Halteres

As the halteres to so-called halteres reduced wings are called. With them, the insects determine their orientation in space. The term is derived from the historical one-hand dumbbells.

One finds halteres in two insect orders:

• Fächerflüglern ( Strepsiptera ): the fore wings are transformed into halteres
• Dipterans (Diptera ): the hind wings are transformed into halteres.

This stub wings consist of a stem and a thickening at the end and are similar in shape drumsticks. Particularly at the base, they are covered with numerous sense organs in the form of dome-shaped sensory organs ( sensilla Campaniforme ), perceive the bending of the cuticle. The halteres are antiparallel to the wing beat at a high frequency on - and cut off and measure the speed and acceleration of the rotation according to the principle of a vibrating gyroscope.

The halteres beat up and down with the wing beat frequency. You will complete from an oscillating motion, the geometry has the same properties as a circular motion. Much like a centrifugal pendulum has a tendency to resist forces that attempt to topple its vibration level. Changes the direction of flight of the insect, insists the plane of vibration of the head holder and the base of the holder stems bends. Through the sensory features of the insect direction and magnitude of displacement of the holder base measured and appropriate corrective movements can be controlled.

The vibrational levels of the halteres are approximately perpendicular to each other and each at an angle of approximately 45 ° to the longitudinal axis of the insect.

The blowflies ( Calliphoridae ) of the oscillation radius of the halteres is covered by a hair- occupied chitin Crescent, which probably has the task of protecting the halteres from the influence of wind gusts.

You can watch In the blowfly Calliphora erythrocephala that the holder vibrations associated not only with wing movements, but also always take place during running movements. Perhaps this sense organ is sensitive enough to measure changes in general direction of movement.