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Photo#135571
Earwig Parasite

Earwig Parasite
Richmond Hill, York Region, Ontario, Canada
August 7, 2007
Size: 84 mm
I just thought I'd share this image of a rather unusual find. I captured an earwig and kept it for a few days. It seemed to do fine until I found it dead one day. That's when I noticed something else in the jar - a roundworm.
A great number of internet sources mention that Earwigs are attacked by "two fly parasites, a roundworm parasite and a fungal disease" - but very few go on to specify the species involved.
Only after a long search did I find this article (here) which lists this parasite as a Mermis micronigrescens. Further internet searches came up with M. nigrescens, a grasshopper parasite. I'm not particularly interested in worms, just wanting to find out the name of this parasite.

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Earwig Parasite Earwig Parasite

Horsehair worm?
I suspect this is actually a horsehair worm. The part about the water would make this seem likely. In nature, horsehair worms drive the host into water when the worm is ready to exit. I think a nematode would be smaller, too.

 
Horsehair worm
Hmmm, I'm definitely not knowledgable on worms. Sorry...
Is there actually a difference between round and horsehair worms? All along I thought they describe the same type of creature. I guess not ... thanks for the correction and info.
And yes, this earwig was actually found in a curled leaf on a creek-side tree, so that also supports what you said.

 
When I was in Zoology
at U of Goo (you say you're a Zoology student there) we had 2 mandatory courses in invertebrate zoology and 1 in parasitology - all of which included examples of horsehair worms (Nematomorpha) and round worms (Nematoda) if I remember right. If it's still like that, you'll be getting into the juicy details sooner or later...

 
Yes...
I'm taking Invertebrate Zoology I right now, and am enjoying it very much. Should be getting to nematodes near the end of the course. They took out parasitology as a perequisite ... but it sounds interesting nonetheless.