The Mystery Insect

June 27, 2009 6:50 PM

Insect Identity Crisis: So I took a picture of what I originally thought was a mosquito on a leaf, but upon closer inspection, realized it was something else all together.

After searching AskMe and the rest of the internet (I googled, I swear!), I'm at a loss. It'd probably fit on a dime, for idea of scale, and as you can see from the picture above, has a black spot on each wing. Alas, I seek the wisdom of the Mefi One Mind, please help me with your assistance.

posted by Atreides to science & nature (21 comments total)

It has two wings, which, I believe makes it a fly... try this page...
posted by HuronBob at 7:07 PM on June 27

What a great photo! I'm guessing it's a wasp of some kind.
posted by rhartong at 7:08 PM on June 27

Thanks, rhartong. I neglected to mention that this fellow was snapped in central Missouri. I'm scanning the bugs on the page you suggested, HuronBob, and I think you're on the right track. Thank you for the help so far!
posted by Atreides at 7:12 PM on June 27

My guess is that it's some sort of hoverfly.
posted by Chocolate Pickle at 7:12 PM on June 27

Robber fly
posted by Crotalus at 7:26 PM on June 27

I think it's a robber fly.

Better picture here, sixth image down.
posted by foooooogasm at 7:27 PM on June 27

I think the consensus has it, it's some kind of robber fly that just hasn't fully developed yet. Thanks for the quick responses, everyone, all greatly appreciated!
posted by Atreides at 7:34 PM on June 27

"it's some kind of robber fly that just hasn't fully developed yet."

Whatever it is, I shouldn't think it will get any bigger now it's got wings.
posted by Razorinthewind at 5:56 AM on June 28

My thought was toward the abdomen, which appears not 100% developed. I'm no bug expert (obviously), so if that's its fully developed state, pardon my inaccurate statements. ;)
posted by Atreides at 6:23 AM on June 28

I vote hoverfly too. A better view of the head could settle it (robber flies have a distinct beak, hoverfly mouthparts are small to invisible) and robber flies are generally pretty big (longer than 1.5 cm) and more heavily built than the pictured fly.

As Razorinthewind notes, a fly with wings is an adult, and will not grow or change for the rest of its life.
posted by hexatron at 6:29 AM on June 28

Hrm. I'll see if I can't snap another picture (front) tomorrow of one of this fellow's kin. It's on my walk to work, so I'll just have to hope there are some around on the plant I found this guy on. Last time, there were several on the leaves or buzzing around.

It seems like the hoverflies, in general, are a bit thicker, which is giving me cause for hesitation. I'll definitely try and grab a better snapshot. The insect identification drama continues!
posted by Atreides at 8:22 AM on June 28

I would just like to chime in with: great pic atreides
posted by FusiveResonance at 8:37 AM on June 28

Robber fly! The abdomen part is normal, and fully developed. The fly in this picture is female, and the black protrusion you see is the ovipositor. Your fly is male, and has no ovipositor - see this guy from wikipedia for another male to compare with. Your fly also has wing-spots, which are often male-specific in flies. No idea what species, though- maybe Ommatiinae?

/dork
posted by metaculpa at 10:45 AM on June 28 [1 favorite has favorites]

Thank you, FusiveResonance, I stumble my way in an attempt to mimic the photographer's art.

Metaculpa, you make a great argument.

I'll still try and snag a full frontal of these buggers tomorrow just to add to the weight of evidence, though!
posted by Atreides at 2:47 PM on June 28

All righty, this morning I hunted for one of these guys again and saw one fly away and found another one conveniently (for me) captured in a spider web...and then to my surprise, in the process of being nibbled on by a small nearly translucent spider. I managed to take a picture of the fly's head and also a profile shot.
posted by Atreides at 6:23 PM on June 29

And if I can play upon your generosity and knowledge a bit further, any help on this mystery fly (a neighbor to the above), would be awesome. Many thanks!
posted by Atreides at 6:45 PM on June 29

Mea culpa. Also, everybody else culpa.

The fly is a snipe fly Rhagio scolopaceus and not a robber or a hoverer.
Here it is on flicker
or you can goog the latin name and find more about it.

Now you can organize a snipe hunt.
posted by hexatron at 5:33 PM on July 1

Your little green friend seems to be a species of the family dolichopodidae
There are about 7000 (known) species in this family, though most don't live where you do.

For comparison, the Wolfram gadget says there are 5416 known species of mammals, and most of those are bats and rodents.

In the future, please try to include the size of the bug. I assume the green fly is 5-8 mm long.
If it is 2cm long (as big as a big horsefly) you've got something else there.

You also have a real talent for insect photography, and a damn steady hand.
posted by hexatron at 6:07 PM on July 1

Well, it looks I'll need to do a bit of unmarking best answer. ;)

Thanks for coming back to the issue after the delay. The little green fly would easily be able to stand on a dime's surface.

As for the photography, a great help is having a wonderful little Canon Powershot with a fantastic macro mode and built in image stabilization.

Thank you again, hexatron, checking back in with a dead on answer!
posted by Atreides at 5:50 PM on July 3

Actually hexapod has it almost right it is a fly from the Rhagionidae family but it isn't Rhagio scolopaceus unless you have giant mosquitoes where you are from you'd never have mistaken a R. scolopaceus (8-16mm) for a mosquitoe. Your fly is from the genus Chrysopilus. This one looks to be Chrysopilus asiliformis (small delicate species 4.5-6mm, with yellow legs, and dark banding on male abdomen).

See here.

BTW a rule of thumb for sexing Diptera is to look at the eyes. If they meet in the centre it is a male, if they are separate female. Unfiortunately the rule doesn't work for all species but for most of them it will stand.
posted by lilburne at 4:23 AM on July 4

Ah I see you've put up a couple of other shots I hadn't seen the later two. The first is Chrysopilus asiliformis. The other two individuals are indeed Rhagio scolopaceus.
posted by lilburne at 4:33 AM on July 4