OT: What kind of bug is this?

Whistle
1

Out on the lot (asphalt) there is a depression along the garage about 1-2 feet wide and 15-20 feet long and a few inches deep that pretty much stays full of water. It is also full of algae and god knows what. The other day I saw something darting around that looked at first like small fish or tadpoles which would be pretty much impossible. What it turned out to be is a colony of these…

They are quite fast. and seem to belong in this kind of environment because they are very well camouflaged amongst the algae. They measure from 1/2" to 1" long. About the size of crickets and they never leave the water. Nobody here has ever seen one before. Any ideas? Thanks!

-Paul

2

Looks like the nymph stage of some kind of insect…doesn’t look like a dragonfly nymph to me. Hmmm.

Then again, the head does look like it. Entomologists?

3

It is most likely the larval stage of some sort of insect. Lots of insects use water as their egg laying and larval stages.

Don’t have a clue which though.

4

We do have a lot of dragonflies around here so that would make sense. We also have a lot of mosquitos and there are NO mosquito larvae in the water and there well should be. I have guessed that these guys have eaten them up.

5

if they eat mosquito larvae I want some.

6

Dragonfly nymphs are voracious predators.

Then again, maybe this is a Water Weasel nymph! :astonished:

7

They’re dragonfly larvae, not nymphs. And they ARE hell on mosquito larvae, not to mention small minnows and fish fry, tadpoles and just about any small arthropod. They’ll eat just about anything, including stuff bigger than themselves.

They’re vicious little buggers, but useful.

8

Not nymphs?

9

I beg to differ,

They are dragonfly nymphs not larva.

The image is a wee bit fuzzy, however, it looks very much like a dragonfly nymph.

One of my favorite insects that I love sharing with the kids when I lead aquatic safari.

http://www.bugsurvey.nsw.gov.au/html/popups/bpedia_07_tol_dr-ny-a.html

Here’s more info on it.

Cool little critters.

Laura

10

That is definitely a dragonfly larva. Technically, it should be called a naiad, which is the proper word for an aquatic nymph, according to old-line entomologists and classical scholars. They are called larvae due to general usage, I believe because of their resemblance to amphibian (frogs, salamanders, etc.) larvae. Dragonflies, like some other insects, have incomplete metamorphosis. Insects with incomplete metamorphosis hatch from the egg as and go through a number of molts as a nymph or naiad, then molt for the last time as an adult.

Insects with complex metamorphosis are a larva (grub, “worm”, caterpillar, etc.) after hatching from the egg. They go through a number of molts as a larva, but become a pupa during the second to last molt before molting from the pupa as an adult. The difference in structure between a larva and adult is so extreme, they need the intermediate pupal stage that has no ability to move, just to lie there and go through a thorough reorganization of its anatomy.

When the dragonfly “larva” is ready to molt one last time to an adult, it will climb out of the water up a plant stem or vertical surface and then molt (shed its skin)and then rest long enough for its new adult skin to harden before flying for the first time.

As you can probably tell, I’m an entomologist.

Rod

11

I bow before you Rod :slight_smile:

Tis a paid hobby for me.

I love the part about molting of the skin.

Who needs Scifi when we have insects. No need to watch Aliens.

12

Laura, that makes me laugh. The first time I ever saw a tomato hornworm, I thot some creature from the Amazon had stowed away and escaped at SF Airport…geez they’re ugly and huge…and very gross to kill…

13

I’m a frustrated entomologist, I ended up learning most of what I know as an “apprentice”. I worked for a good number of years as an insect curator in the W. F. Barr Entomological Museum, the large working academic collection at the U of I. We did a hell of a lot of both basic science and applied stuff. I was a terrible student, but good at picking things up at work. I have the experience of someone with a masters degree, but I haven’t even gotten a bachelors.

Rod

14

Mr. Sprague,

Thank you for the confirmation. I have already told the clean-up guys to keep water the area every day to keep their environment intact so that the little dragon flies can finalize their pupation. Anything to keep the mosquitos away!

When the dragonfly “larva” is ready to molt one last time to an adult, it will climb out of the water up a plant stem or vertical surface and then molt (shed its skin)and then rest long enough for its new adult skin to harden before flying for the first time.

Should I place a plant or something nearby? there is nothing for them to climb on when they’re ready. It (their environment) is right next to a cinderblock wall.

Thanks,
-Paul

15

They should do OK on a cinderblock wall,
Rod

16

Excellent pic, BTW
I found the shed skin of one of these buggers just above the high tide mark on the Hudson last week while kayaking. What a fascinating life cycle!

17

http://www.gridclub.com/fact_gadget/horrible_but_true/natural_world/prehistoric_life/1071.html

Would love to see a fossil of one of these.
Could you imagine a dragon fly the size of a seagul?

18

I wouldn’t want to meet it in person.

Sonja

19

I’m confused. We’ve been told repeatedly here in Utah to get rid of any standing water on our property since that’s where mosquitoes hold their bacchanals and orgies. Shouldn’t Paul be trying to get rid of the water (and thus mosquitoes)?
Susan

20

Susan you are indeed right about that and I am definitely going to get rid of the indentation in the asphalt but I have decided to wait until the Dragonflies have matured. Due to their being in the water there aren’t any mosquitos at all around there this season.