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Hi!
It is a picture of Vespidae, we knew that all of the insects have compound eyes which formed of numerous of ommatidia! I have a question! If you notice in this image, you get noticed about these eyes, why are they shaped? Are they ommatidium or another things? Thank you

Sara (21392)

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Welcome to the forum Sara ... I can't answer your question but this isn't really to do with identifying Diptera so I will move the thread to a more appropriate forum, such as the General queries area ;)

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Oh! I'm sorry:S, I'm a newcomer, because I got it wrong!:| thanks a lot for your attention and lead me!:)

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No problem :) I re-read your question and I think I understand now. Basically the dark shapes that you see on insect's eyes sometimes are an optical effect due to the structure of the ommatidia and the way that light strikes them and then is reflected back to the observer.

You can think of each ommatidium as a transparent cylinder and thousands of similar cylinders are packed together but, as the eye surface curves each cylinder points in a slightly different direction to its neighbours. Generally speaking, light is either bounced off the ommatidia up to your eye (giving you the impression of colour) or when you are looking down directly into the ommatidia it vanishes down into the cylinder and doesn't bounce back out (giving you a black/dark patch). :)

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Thank you very very much!:) now a question occurred to me!! This insect exist numerous ommatidia, like many other insects; well, against the large number of ommatidia, why number of optical effects are low and so large? This intensive eye, does not conform with state, slightly! Unless, we accept that, optical reflections state, current only in some ommatidia! Doesn't it?:|:o