Ologamasidae, ventral - Euryparasitus

Moved

… v belov, 5 March, 2012 - 10:46pm

Moved

… Edward L. Ruden, 4 March, 2012 - 5:20pm

Photo#618001

Hi Ed,

Poecilochirus (Parasitidae) are obligate associates of Nicrophorus beetles and nowhere near this large (1.9 mm!). This mite seems to belong to the Ologamasidae s.l. From the ventral views you can see this is an adult female with a large ventrianal shield that captures all the ventral setae, a dark spot near the top of the genital shield, the lateral shows a short peritreme, the dorsal the divided shield, and the giant size suggest just one thing to me. Only problem is that sternal seta 4 seems to be off the shield, but that can happen in some ologamasids.

I'm pretty sure this is a species of Euryparasitus (Ologamasidae) or the closely related genus Cyrtolaelaps. Unfortuantely, I can't see the key character (Euryparasitus has a pair of small platelets flanking the tritosernal base), but Cyrtolaelaps are supposed to be under a millimetre.

Adults of both genera are usually associated with the burrows of small mammals. I've never actually seen one myself that I can remember, but I'll check with Hans Klompen at Ohio State who has worked on them.

Cheers,

Dave Walter

… Dave Walter, 4 March, 2012 - 11:58am

Thanks

There is no guide page for Ologamasidae yet, so I'll move it to Superfamily Rhodacaroidea, which Fauna Europaea places it under. As a new family for BG, this is a significant. If you're sure of the family ID, I will request a new guide page for Ologamasidae.

As to genus, I'll take and post a higher resolution ventral closeup of the sternal region. Don't overlook the link I provide already to the high resolution image as submitted.

Also, I've double-checked the body length. It is 1.90 mm.

… Edward L. Ruden, 4 March, 2012 - 5:19pm

ID Confirmed

Dave Walter replied by email, "Yes, I think I can see the corner of the platlet in your new image, so your mite should be a species of Euryparasitus. You should start a new page for Ologamasidae."

… Edward L. Ruden, 5 March, 2012 - 10:13pm