I discovered this Cunaxid in a soil core sample and tried to key it. I came down to Scutopalus, which if correct is the first record for the genus in North America. Since I'm new to this I would like expert confirmation. I attached photos below of all the relevant features for identification.
Hi Brendan,
I assume you're using the key of Skvarla et al. To be able to use that key effectively, mites need to be cleared and slide-mounted. I can't see enough to work out the palpal setal formula, leg setation or even one of the more important features of Scutopalpus, the "well-defined" dorsal plates. Although these may be softer than "well-defined" I still might expect to see them with a dissecting microscope, so I would be cautious about calling this Scutopalpus.
Contacting any of the authors from that paper would be good start to an adventure in cunaxids! They are cool little mites.
Best wishes, Owen.
Owen Seeman Thank you for the kind response! I will definitely need to go back and look at a cleared specimen (this one was already slide-mounted.) However, there shouldn't be another genus that has the tarsi bulbed setae (photo 4) and smooth palpal claws, unless this is a new genus. But you're right, this should be confirmed with setation counts.
Does NaOH work for clearing?
Thanks again,
Brendan
Hi Brendan,
I couldn't see the "bulbed" setae in your photos. It's really tiny and often needs oil immersion to see - but, surprisingly, it seems like a strong feature. It's like the tip of a singed hair (and remember it's the longest seta on tarsus III-IV that you're looking at).
For the palp claw, you often need a decent microscope to see this structure properly. It helps if you squash it a bit so the palp lies flat.
NaOH is pretty harsh as a clearing agent. Don't let a mite sit in it for long, wash it well afterwards. Lactic acid is preferred, a chloral-hydrate based clearing agent better if you can get your hands on it (Nesbitt's fluid).
Best wishes, Owen.
Owen Seeman Thank you for the clearing info!
Is this not the bulbed seta? If so what is it?
Just heard from Dr. den Heyer who says this is either Dactyloscirus or Armascirus. I seem to have messed up the palpal segment count. I'm happy I could get a correction though, it helps with the learning :)
Excellent! Dr den Heyer is fantastic. I think you're seeing the empodial hairs, which can be blunt. The long setae are back on the segment whereas these arise from the tip of the tarsus.
Good day, hope you will have a more clear picture of the mite. I am glad that Owen and Dr. den Heyer are helping you, you are in good hands .
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