Ptenothrix

In the past few days I’ve been looking at various means to both confirm existing species, and separate potential new ones. Mainly this is going to be done by microscopic features and DNA barcoding, but once we have the basis built there, we can start to pick apart which visual patterns are reliable reflections of that (if any).

One of the main problem areas amongst the described species (that we know of) is the difference between P. beta and P. maculosa. Christiansen & Bellinger note that they’re very visually similar, and they’re not wrong. From Frans and Bugguide, we have a partial concept that the dorsal posterior has an “ice cube tray” on P. beta, and a single longitudinal line (with possible confounding patterns around it) on P. maculosa, but there are also plenty of in between ones.

To solve this, one method will be microscopy. Going back to the descriptions, we see that P. beta is listed as the only member of the genus in North America that has clavate tenent hairs (on every foot, no less). This basically means that on the front of the “ankle” area just above each claw, there are some common hairs that most springs have, and these are the “tenent hairs”. Clavate basically means they’re sorta spoon-shaped with a wide flat tip.

One thing that’d be great to straighten out is to seek out all the different colour-forms of P. beta and P. maculosa that we have, and separate them using the clavate tenent hair check, and then post a definitive list of which pattern is which.

Just gotta get out and find some springs!