Aquatic Insects and Bioblitzes (Friday 5)

A few weeks ago, I was given a really fun opportunity to be a part of a bioblitz workshop.  Bioblitzes, for those unfamiliar with them, are biodiversity documentation events, often done over a short time period and at a specific facility, to document and/or monitor the species present on the grounds.  Bioblitzes often invite the public to take part as a way to get help collecting and identifying species while also teaching everyone about local natural history.  The workshop was geared toward park and environmental education center staff that are interested in using bioblitzes to make sound management decisions and/or educate the public.  A variety of scientists demonstrated how to collect or otherwise document a range of species, including reptiles and amphibians, small mammals, large mammals, birds, plants, and insects.

Guess which part I taught?  Aquatic insects!  I manged to get about half of the 40 participants actually IN the water to look around for aquatic insects in the urban stream that flows through the park hosting the workshop and we found… not a lot.  The neighborhood adjacent to the stream has an awful drainage system that dumps all the runoff right into the stream without any sort of filtration, so the stream floods often.  Still, we found some interesting things!  They included this:

Net spinning caddisfly larva

Net spinning caddisfly larva (Hydropsychidae)

That’s a type of net-spinning caddisfly!  They build little silken nets across rocks in swiftly flowing areas of streams to catch food, then hook themselves into the nets.  While caddisflies in general are considered good indicators of water quality, this particular group is capable of reaching HUGE population sizes in some quite heavily disturbed areas.  Still, always fun to find caddisflies.  We also found some adults:

Net spinning caddisfly

Net-spinning caddisfly adult

This little guy was hanging out on a blacklighting sheet, presumably in the same spot it had sat the night before.  Caddisfly adults look a lot like moths, but instead of having scales on their wings they have hairs.  Their order name, Trichoptera, means hairy wing, so it’s easy to remember this distinguishing characteristic if you know your roots.

We also found these lovely larvae in the stream:

Crane fly larva

Crane fly larva

Crane flies!!  They’re huge and squishy and ooze all over when you catch them, so they’re really quite gross.  Many have gnarly looking fleshy bits on the back end that they use to breathe (which naturally makes them exciting to me!) and some have a sort of ribbed appearance like this one.  Unlike a lot of fly larvae, they actually have a complete, hardened head, but they keep it retracted inside their bodies.  I enjoy finding these larvae and they’re really fun to show off to people when you find them in a stream.  That huge monster ends up turning into something like this:

Crane fly

Crane fly

I know I’ve said it before and I’ll say it again: crane flies are harmless to people!  A lot of people are scared of them and many think they bite, but they do not.  They’re also not giant mosquitoes – completely different groups!  I think they are really beautiful.

I’m going to wrap up with this

Common baskettail

Common baskettail

There weren’t a lot of dragonflies out during the workshop as the dragonflies were really just starting to come out, but one of the reptile and amphibian guys found this dragonfly on the ground.  It was still alive, but clearly had some issues when it emerged as an adult and I doubt its wings worked.  Granted, I have seen some butterflies flying with as little as a wing and a half, so who knows?  Maybe this little dragonfly is still zipping around the pond, hunting insects and having a great adult life!

Even though I’ve participated in enough bioblitzes and done field work with enough scientists that I didn’t learn many new things about how to sample for a variety of organisms, I still had a great time at the workshop!  The people who attended were really excited about it all, so it was a lovely, energetic group.  I also got to see a white-footed mouse, a great horned owl, several turtles and frogs (including a new-to-the-park’s-species-list river cooter), a new-to-me dragonfly species, and a variety of insects.  Plus, I got to spend an afternoon in a stream teaching people about aquatics!  It’s hard to beat a day spent with other nature geeks.  Hope I get to do it again soon!


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