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Photo#233177
Fungal infection or parasitism? - Euplectrus

Fungal infection or parasitism? - Euplectrus
Empire Lake, Ferry County, Washington, USA
August 9, 2007
Found attached to the upper end of a flower stalk at the north end of Empire Lake.

Is this the result of a fungal infection or parasitism by another insect? The white "puffs" seem to have small black structures attached.

Images of this individual: tag all
Fungal infection or parasitism? - Euplectrus Fungal infection or parasitism? - Euplectrus

Moved
Moved from Unsolved bug-related mysteries.
After further reflection, I think the black things could be meconium--the wastes voided by the Euplectrus larvae just before pupating, like the yellow piles in this image of eulophid pupae:

[Edit]: Here's a paragraph salvaged from a dead page on the U-CA Riverside website (which I accessed by clicking the "cached" link in a Google search):

"Euplectrus has interesting pupation habits. When the larvae finish feeding on the host and have completely sucked out the fluid contents, they leave the dorsal position and seek the underside of the deflated host, where they arrange themselves transversely, in a single orderly row in some cases, and prepare to pupate. A light weblike cocoon is formed which binds the host remains to the leaf, the latter thus serving as a protective covering. Several authors have called attention to the fact that the material from which the cocoon is spun is derived from the Malpighian tubules rather than from the salivary glands and that the slender tapering tip of the abdomen of the larva serves as an "arm" in the construction. The meconium is cast by the prepupa, and sometimes it is ejected from the cocoon. The pupa lies upon its dorsum and is attached to the substrate by means of the last larval exuvium, which envelops the tip of the abdomen."

The meconium is not described, but the same site describes the meconium of another eulophid as being in the form of black pellets. It appears that in this case not all of the larvae were able to fit under the caterpillar, so some made cocoons on top of it. A few seem to have done so in the image I linked to in my last post as well.

 
Black bits on the leaf
While searching for identification of some black pupae of a parasitoid, I came across this photo of the circle of black pupae. They are pupae of a parasitoid. I found a duskywing caterpillar on oak. Within a day, parasitoids emerged from the larvae. Three days later, they made these little black pupae. This is the second time I've found them (the first emerged as little flies and I will be taking them for identification at the University of Florida). Today I found another duskywing caterpillar with the same parasitoid larvae freshly emerged from the caterpillar. I have photos to submit of them as larvae and as pupae. It will be great to find the actual identification of these critters!

Fungi. No, parasites! ,,,actually....Fungi!
The poofy clusters of hairs look like empty wasp cocoons, but since there are hairs all over this insect, I think that they are actually fungi. You could try coming back tomorrow and rephotographing it to see if they've grown at all.

 
another thought
I can't tell from the picture, but it just dawned on me that these might perhaps be seeds (with their little tufts of fluff attached) that happened to stick to the dead caterpillar. They remind me a little of the seeds of Salix or Populus, but I suspect they aren't those. And then again, they could be spore bodies of some fungus afterall (or ??? little seeds stuck to fungus growing out of the caterpillar).

 
Maybe...
Euplectrus species seem to spin loose cocoons somewhat reminiscent of what is shown in these photos

That still wouldn't explain the black things, though...

 
another thought
This looks rather similar. So, what happens to the pupal shell when the adult insect emerges. The photo is just slightly out of focus, so it's hard to really tell what the little dark bits look like. The impression is of an oval solid object, but maybe curved thin bits? Perhaps these little dark things are bits of pupal shell still stuck to the cocoons? Or - what he said (below) :)

 
pupal skins
I think they may still be in the cocoons (which they should be, as far as I know--I haven't come across any mention of mobile wasp pupae in my research)-- if you follow the outline of the right side of the caterpillar, there are two spots along the top half where something dark inside the alleged cocoons breaks up the outline. Looking at the other cocoons I can imagine similar dark spots, but these two are more unambiguously un-imaginary.

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