Sonntag, 10. Juni 2012

The Dragonfly – a flying jewel

Sympetrum vulgatum. German name: Heidelibelle

Dragonfly, that name fits very well for an animal with that shape and majestic looks. In German we call this animal “Libelle” and I think it’s also a suitable name for such flying belles. Unbelievable that the father of the German name was thinking about a fish when the “Libelle” got its name…
Find more infos and pictures under the cut.

There’s a huge variation of dragonflies in the world: big and small ones, colourful and, camouflaged ones, a few are thin like a match and some others look flat like just being stepped on. This diversity and the fact that they fly like helicopters fascinates me. Dragonflies even lived when dinosaur walked over the earth! The wing-span of the ancient dragonflies was about 70cm! I’m glad that our dragonflies are not that big anymore.

Libellula quadrimaculata. German name: Vierfleck (four dots)
You can watch dragonflies on ponds, natural lake shores or creeks. They don’t really need those habitats for foraging but they will need them for reproduction. When a male finds a female he will hold the females neck with his “tail clip genitalia”. Each species' male genitalia fit the head of only the female of that species. Once the male has grasped a female, they fly in tandem for some time. After that the female stretch her tail to the “sperm bag” on the end of the males torso, so they generate the typically wheel formation. After mating the female lays the eggs into the water. Some species “dive” and drill holes into plant caulis and lay the eggs inside!

Wheel formation. German name: Azurjungfer.
Tandem. don't know the species name.
The female lays eggs into the water! It's the Azurjunger again.
Hard to believe but dragonflies spent the bigger part of their lives in water! Out of each egg hatches a larva which doesn’t look much like an adult dragonfly. The larvae are predatorily and like to eat other water insects, pollywogs and sometimes even tiny fishes! How long a larva stays in water depends of the species. Some species spent several years in water!

Big larva! Maybe from the Aeshna cyanea.
Another larva, a smaller one.
But for every larva comes the day to finally get out of the water. Often they climb reed caulis for doing so. Then the wonder happens: Out of the larva hatches a full grown dragonfly! Like butterflies they need some time for to push blood through the long wings. That’s a dangerous time for the dragonfly, because it can’t move and escape! But when it’s done the dragonfly flies on to search for a territory and a mate. Dragonflies like to eat other insects which they catch out of the air. There is a species which is called “Dragon Hunter” and this dragonfly is not only the biggest of all dragonflies, it even eats smaller dragonflies! How nice…
You can often find exuviae (empty larva shells) on reed caulis. When you are lucky you can observer a hatching dragonfly, too!

Exuviae on reed caulis.
Close up.
Exuviae of the dragon hunter. Pretty strange shape.
Against ample beliefs the dragonfly can’t sting or bite. They are totally harmless for us humans. So don’t freak out if a dragonfly turns into your direction, the little creatures are only nosy ;)

Beautiful little monster ;)
A rare Calopterygidae. German name: Prachtlibelle.
Libellula depressa. German name: Plattbauch. This fella looks like someone stepped on its body.
I hope you enjoyed this entry :)
So, now I'm off for three weeks. Stay tuned, I will come back with other bone stories! See ya!

1 Kommentar:

  1. Wow, your pictures are amazing and I love the way you explain. It's entertaining yet full of information. keep going, I'll be reading. corni