Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Discussion of 2018 gathering

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Photos of insects and people from the 2013 gathering in Arizona, July 25-28

Photos of insects and people from the 2012 gathering in Alabama

Photos of insects and people from the 2011 gathering in Iowa

Photos from the 2010 Workshop in Grinnell, Iowa

Photos from the 2009 gathering in Washington

Blue larvae on caterpillar - Euplectrus

Blue larvae on caterpillar - Euplectrus
Nashville, Tennessee, USA
July 6, 2008
Size: 18 mm
Found on the underside of a boxelder leaf.

Images of this individual: tag all
Blue larvae on caterpillar - Euplectrus Blue larvae on caterpillar - Euplectrus

Expert opinion
Christer Hansson agrees that these are Euplectrus.

Moved from Eulophidae.


are you
going to try to raise them?

I didn't collect them. I'm tempted to go back and see if they're still there, but I'm on the road and it's a bit difficult to raise things.

Nice find!
Some similar images in the guide here

I figured I wasn't the first. It appears that Jeff's

turned out to be Eulophids, yet his larvae and others like them are filed under Braconidae. I guess these should all be moved? Or could they possibly be hyperparasites? It's interesting that his formed cocoons under the caterpillar, similar to the ones that are usually assumed to be braconids. I guess I'd better see if they're still there, while I'm still in Nashville...

It doesn't seem reasonable that the
Eulophids could have hyperparasitized all the "braconid" larvae, so we will assume these are actually Eulophid larvae and move them all there. It's easy enough to change if we're wrong.

Here's a quote from the USDA link on the Info page:
"Euplectrus (Euplectrini: Eulolphinae): The species in this genus are gregarious external parasites of lepidopterous larvae. It is particularly interesting in 2 ways: first, the larvae feed on the dorsum of their host which is often still moving freely about (thus, if you see a free-living caterpillar with larvae on its back, the larvae are almost certainly Euplectrus); secondly, the larvae move below the emaciated host to pupate, spinning silk from the Malphigian tubes to hold the host down as well as to separate themselves from each other. According to Askew (1971) some other chalcidoids spin cocoons (e.g. some Coccophagus-Aphelinidae, Systasis-Pteromalidae, some Encyrtidae), but it is uncommon. "

Any thoughts on whether we should move them all to Euplectrus?

Dr. Hook at St. Edward's University (he specializes in wasps, but not this kind), who ID'ed my image (linked in my other comment) said that he thought Euplectrus was definitely the most likely (for mine anyway, which we went ahead and put in the genus page), and your USDA reference is definitely more evidence ("almost certainly"). It seems like a good bet to me, and we could always move them again if an expert corrected us.

From what I know,
I agree that these are probably Eulophidae. This one of mine

has the same shape but obviously a different color.

...and I just did a quick Google search for "eulophid larvae" and came up with this page, which has a similar ball of eulophid larvae towards the bottom of the page. I've never heard of braconids being in a ball like this; they always seem to be scattered all over the caterpillar when they emerge. So I think I'll go ahead and move mine and similar images to Eulophidae. [Edit: I see the Balabans are taking care of it. Thanks!]

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.