Friday, October 11, 2013

Red Admiral hairy eyes

One of the pleasures of macrophotography is that you tend to notice things in the captured image that you'd never be aware of otherwise.




















Until the colder weather arrived a couple of days ago we had several red admiral butterflies in the garden. I took some extreme close-ups of them, while they were feeding on ripe pears, and noticed in the images .....


































.... that their eyes have this strange hexagonal pattern. Looking closer still, it's clear that .....




















.... the eye surface is hairy and it looks like it's the pattern of hairs, located in between the individual ommatidia of their compound eyes, that is responsible for those large pale hexagons. A comparison with eyes of other common butterflies, like...



































..... this small white, shows a pattern of darker patches on the eye but not a hint of hairiness around the ommatidia.

So I wonder what the hairs' function might be? Maybe they enhance flicker vision - the sensitivity of compound eyes to movement of objects across the field of vision............? 

Hairy eyes are not uncommon in insects - click here, for example, to see a scanning electron micrograph of a honeybee's hairy eye. Another possibility of that the hairy surface might stop pollen sticking to the eye surface in these flower-visiting insects.........



5 comments:

  1. Phil,I love to visit your blog where I always learn something interesting and new. Today's hairy eyes are a surprising information to a dull maths teacher like me!

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  2. Thanks lotusleaf, I could use some maths teaching from you - it has never been my strong subject!

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  3. Hairy eyes? How much I have to learn. Thank you Phil.

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    Replies
    1. Amazing, isn't it - so much variety in nature......

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  4. Richard Pegler has left a new comment on your post "Red Admiral hairy eyes":

    Flabberghasted by this revelation, Phil! It also makes me realise that my own recent efforts with 'macro' are only just scratching the surface!

    Keep up the good work.

    Richard

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