Sunday 12 November 2017

Know Your Wings!

It looks likely that unless we have some warmer weather next weekend, I may have seen my last dragonflies and damselflies of 2017. It has been a very successful season personally and no doubt in due coarse, I will spend some time reviewing the season with some of my favourite images. One of the many fascinating aspects of the dragonfly and damselfly is the structure of the wings and I have used this quite often to effect in some early morning dewy photos but just like many I suspect, why do they look as they do? I decided to read through some of my books and look at a few internet sites to see whether I could provide myself with some of these answers. The often overlooked pterostigma (the thickened or coloured cell in the outer wing) has an important role in the flight of the dragonfly. It is actually slightly thicker than the rest of the wing and provides stability during gliding. It can also help provide identification to species with different colours and shapes. Another question I needed answers for was 'why are the cells different sizes and shapes in the wing?' If ever you have looked at a dragonfly wing up close, you will notice that the cells are different in size and shape. Some have three sides, others can have four, five or six sides. The number and shape of cells in a particular area are designed to handle force very differently when in flight, gliding and turning. I don't think I will ever look at a dragonfly or damselfly wing again now without appreciating just what a work or art and design they are. Whilst on the theme of wings and seeing most species can be identified through their shape of wing, pterostigma shape and colour, costa colour etc, I thought I would set a challenge to see how many visitors to this blog can identify. I have got to be honest and say, there are a few that I don't think I would get myself. For some photos, I have included a very small part of the thorax to maybe help with some identification. I will post the answers in my next post in a week or so but you are more than welcome to post your answers on this blog or to my twitter feed (Kent Dragonflies). 

Number 1 

Number 2 

Number 3  

Number 4 

Number 5 

Number 6 

Number 7 

Number 8 

Number 9 

Number 10 

Number 11 

Number 12

4 comments:

  1. Flying high, fantastic Marc. Aren't they so beautiful.

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    1. Many thanks Bob. Just superb pieces of nature. The more you look at them, you realise they are nature's stained glass windows.

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  2. I now realise how much of a beginner I am in my knowledge of the Odonata, Marc. I'm ashamed to say that I could only identify, with any degree of certainty, the two most obvious ones without reference to the guide books. I shall now be consulting the books to try and rectify the situation!

    Thank you for an excellent challenge which, I hope, will be most useful - if I can still remember what I learn when next season comes around!

    With my best wishes - - - Richard

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    1. Thanks for looking in Richard. They can be tricky but like all things, there are clues to be seen which will point you in the right direction. I will post the species next week but in the mean time, keep looking and practising.

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