Dragonflies
| Dragonflies | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
.jpg)
Spotted darter ( Sympetrum flaveolum ) |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Anisoptera | ||||||||||||
| Sélys , 1854 |
The dragonflies (Anisoptera) are a suborder of dragonflies and globally include about 2,800 species that are divided into eleven families.
features
The large dragonflies are usually larger and more powerfully built than the small dragonflies . They have much larger compound eyes that meet in the middle of the head in many species, but are always less than an eye width apart.
The hind wings are usually a little wider than the fore wings. In many species the wings are partly colored or darkly spotted. The wing veins are very rich. A noticeable feature of all dragonflies is the wing triangle near the base of the fore and hind wings, the shape of which plays a role in distinguishing the families.
Dragonflies are often very skillful and persistent fliers. You can move both pairs of wings independently of each other, make very fast turns, and sometimes even fly backwards. There are also migratory species among the dragonflies that regularly cover very large distances.
In the resting position, the wings are spread apart from the body. Large dragonflies can also fold their wings over their backs, similar to what is usual with small dragonflies. The animals only do this in exceptional cases, for example in unfavorable weather such as strong wind or rain. Like the small dragonflies and the mayflies, the large dragonflies have no mechanism to fold their wings parallel to their backs. Only the new wings can do this .
The larvae of the dragonfly live predatory in the water. They differ from the larvae of the dragonfly in the absence of the leaf-shaped abdominal appendages. Instead, they have an anal pyramid made up of five strong spikes at the end of their abdomen , which they can use for defense, among other things. The larvae have gills and can move by expelling water from the gill chamber. While the adult form only lives a few weeks, the larval stage can last for several years.
Systematics
Worldwide, the dragonflies are divided into the following superfamilies and families:
- Gomphoidea. only one family:
- Mermaids (Gomphidae)
-
Aeshnoidea
- Noble dragonflies (Aeshnidae)
- Austropetaliidae
- Petaluroid. just a family
-
Cordulegastroidea
- Spring damsel (Cordulegastridae)
- Neopetaliidae
- Chlorogomphidae
-
Libelluloidea
- Hawk dragonflies (Corduliidae)
- Macromiidae
- Libellulidae (Libellulidae)
- Synthemistidae
Dragonflies in art and culture
Dragonflies are the namesake and mascot of the free Unix derivative DragonFly BSD, which was founded in 2003 .
literature
- H. Wildermuth, Y. Gonseth, A. Maibach: Odonata. The dragonflies of Switzerland. Fauna Helvetica, Volume 12, 2005, ISBN 2-88414-024-7 .
