h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Entry: Odonata - Dragonflies, Damselflies and Demoiselles - A87911265
Author: SashaQ - happysad - Editor - U9936370

Here's a little Entry about a group of insects that I enjoyed studying a couple of weeks ago.

Thank you for this.

I like watching damselflies and dragonflies. I think I can identify beautiful and banded demoiselles but I'm not sure about dragonflies.

Am I right in thinking that the order Odonata is ancient and they were about the first creatures to fly?

They go back to the carboniferous and were still producing specimens with two foot wing spans as late as the Jurassic.

The point that they live by means of taking mosquitoes and other flying insects on the wing has many times been an inspiration for spin off science fiction special effects.

Thanks for reading

Yes, dragonfly ID is quite tricky, as the variations between species can be quite subtle... I have an ID guide, which is very handy indeed http://www.buckinghampress.co.uk/british-dragonflies.html

Yes, the Protodonata group does date back 300million years, so the proto-dtragonflies were one of the first to fly... A two-foot wingspan insect would be rather scary - I was startled enough by a three-inch wingspan one that accidentally flew into the house one summer's day, but luckily it went straight back outside again after hitting the wall

There were larger insects of all kinds, including , in the days that had higher oxygen levels. They had very creepy episodes of 'Walking With Monsters'.
http://news.nationalgeographic.com/news/2011/08/110808-ancient-insects-bugs-giants-oxygen-animals-science/

<BB<

though sometimes irritating, all of the odonata are so far as I know otherwise harmless to humans.

See also, 'ant lion lacewings'.

Hi Sasha

This entry is good - well written and easy to read.

Please change the https to http in the links to the photos. This will allow them to work in the old Ripley skins as well as the new Pliny system.

If you want any more photos, I've a nice picture of one of these which you can have:

http://www.flickr.com/photos/eoinmcauley/27881088517/

Thanks Gnomon

The links in the Entry work ok for me in Brunel, but yes I will send copies of the photos to the Editors so they can be added directly to the Entry rather than as links

Oh wow - the photo of the Demoiselle is beautiful indeed Thank you - that will be an asset to the Entry I haven't ever seen one in real life, but I may yet be lucky this year - I've seen a superb number of dragonflies and damselflies already, as the warm sunny weather suits them

Hi Sasha!
A very interesting Entry. I only found the introduction a bit dry maybe.
And very good pictures, also Gnomon's!

Hi Tav!

Thanks for reading - yes, I totally agree the introduction was dry, and didn't convey my enthusiasm for these creatures, so I have updated it

Much better!

“ are all insects, so they have a head, thorax and abdomen, two eyes, six legs and two pairs of wings.”

This suggests that all insects have two pairs of wings. In fact most insects are beetles and they have modified one pair into wing cases. House flies have only one pair, the other pair being reduced to just stumps which may still provide a stabilising effect.

The minute and stubby wing stumps of the diptera (flies), are also import sensory organs allowing the to sense displacements in the air like those produced by a hand descending in a swat.

I updated that - I see that there also exist insects such as silverfish that never evolved wings

That's better|

I saw a dragonfly in the south of France with a body that was 15cm in length and about 1cm thick. You don't mention anything this size. Is your entry only about British dragonflies?

I think it would be better if you put the Anatomy section before the Lifecycle section.

Wow - that must have been a sight to behold!

I've reordered as you suggested, and also included a bit more about dragonflies of the world so hopefully that is better...

It was another hot weekend, so the dragonflies and damselflies were frolicking - I saw a Broad Bodied Chaser http://www.flickr.com/photos/sashaq99/41195548040/in/dateposted-public/