Dragonhunter Nymph

2015 July 25

We all went to the public beach at Dollar Bay on May 2, 2015, and while wading around in the shallows I spotted something floating close to the surface that looked a great deal like a dead leaf. Aside from the legs, that is. On closer examination, it turned out to be this enormous dragonfly nymph.

It wasn’t very active, and at first I thought it was dead, but it turned out to be OK.

Normally it is hard to identify aquatic nymphs, but this one turns out to be pretty unique. Between the very large size and the highly flattened body, it looks to be the nymph of the Dragonhunter, Hagenius brevistylus. The round, mickey-mouse-ear antennae are also pretty distinctive.

It is a bit surprising how much the body shape changes when it becomes an adult. That broad, flat abdomen will turn into the long, thin abdomen that dragonflies have.

This is probably the biggest dragonfly nymph that we are likely to find locally. They seem to mainly live in Portage Lake and the Portage Canal, and in the past I’ve seen them crawl up on shore in some numbers down on the waterfront, when they are ready to molt to adults. They have some superficial similarity to Giant Water Bugs, but this is all convergent evolution due to similar lifestyle – they are almost completely unrelated.

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