Dragonfly with damaged eyes

djeyewater · #1 (**permalink**) 25-05-2010, 12:09 PM

A newly emerged broad-bodied chaser dragonfly in our garden was attacked by ants. I did try to rescue it, but it was too late.

I noticed that its eyes were badly damaged, and wondered how this happened? It did look like the ants were trying to drag it head first, possibly down an entrance to their nest.

I presume the eyes are soft and damaged easily until the dragonfly has dried off? Any idea how the damage would affect the dragonfly's vision?

Dave

Brooklime · #2 (**permalink**) 25-05-2010, 09:20 PM

Hi Dave, haven't any answers to your post but I imagine a dragonfly loosing an eye would be very inhibiting to it's ability to fly and hunt. It's an amazing photo - what equipment and lens did you use?

djeyewater · #3 (**permalink**) 26-05-2010, 08:52 AM

I don't know if the dragonfly's eye being damaged means it wouldn't work at all. Assuming the photoreceptors still worked okay, I imagine that the Dragonfly would create a garbled image in its brain (since the photoreceptors in the damaged area would be receiving light from a different angle than what is normal). Possibly the dragonfly's brain may be able to compensate for this though, similar to how humans can adapt to wearing upside-down glasses?

I have seen hoverflies previously with slightly damaged eyes (just a bit of an indent, nothing like this dragonfly), and while I didn't study them closely, they seemed to be okay.

Regarding the photo, I used a Canon 450D camera with the MP-E lens (a specialised Macro lens that only shoots at 1-5x magnification) and the MT-24EX Macro twin flash with home-made diffusers.

Dave

Brooklime · #4 (**permalink**) 26-05-2010, 07:57 PM

Hi Dave, thanks for the reply. Lets hope the dragonfly does manage to adapt his eyesight. Their eyes are pretty incredible and they differ massively from their nymph stage. We have a few Darters emerging from the pond now and it is an amazing transformation. Many thanks.

djeyewater · #5 (**permalink**) 26-05-2010, 09:53 PM

The one I photographed won't be adapting to his eyesight anytime soon - by the end of the day only the head and thorax (with wings still attached) were left, and the next morning there was nothing left. Unfortunately I missed the ants dissecting it, would have been interesting to watch.

We had at least 2 (possibly 3) broad back chasers get away okay though. Our pond needs some more nymphs now though, as it is teeming with mosquito larvae.

Dave