Catch mask

from Wikipedia, the free encyclopedia

The greatly elongated lower lip ( labium ) of the larvae of dragonflies and other insects, especially short-winged species of the genus Stenus , is called the catch mask . It is used to catch prey and for this purpose can be folded in or out in a flash.

Dragonfly larvae

Lower front part with catch mask in an empty exuvia of the blue-green mosaic maiden ( Aeshna cyanea )
Dragonfly larva is eating on a fish

In dragonfly larvae, the greatly elongated lower lip is transformed into a two-part grasping organ, which has a few mobile appendages with teeth or thorns at the front end. In the rest position, this safety mask is folded under the head and the front part of the chest by means of a corresponding joint (labial socket). If a potential victim is within reach, this clawed instrument pops out and the prey is grabbed. The prey is folded forward to catch the prey via the labial musculature, the prey animals are grabbed and held by the teeth at the front end of the catching mask.

Stenus

The trap mask of the short-winged species of the Stenus genus is everted when the blood pressure increases . The prey, mostly springtails , stick to a sticky secretion at the tip of the labium, which is formed here by a gland.

supporting documents

  1. ↑ a b c Fangmaske In: Herder-Lexikon der Biologie. Spektrum Akademischer Verlag, Heidelberg 2003, ISBN 3-8274-0354-5 .
  2. ↑ G. Jurzitza: The Kosmos dragonfly guide . Franckh-Kosmos, Stuttgart 2000, ISBN 3-440-08402-7 , p. 35.