On 2/17/2024, I embarked on my first winter stonefly (Taeniopterygidae and Capniidae) hunt. We were at a new site for my organization, an addition to our usual site. It was another site along the same river, but about a mile or so further downstream. It was pretty cold and a little snowy, but the sun was shining very brightly. It didn't feel like it was doing much though, besides giving my minimal exposed skin some vitamin D, and perhaps brightening the overall mood.

We were only there to count the winter stoneflies, and record the presence of any other macroinvertebrates we found. My coworker introduced me to the volunteers as someone who is "very good at IDing macros." Oh boy. I was on "picker" duty, picking out the macros from the samples taken from the river. It felt right, considering I was the best identifier at the site, even though that was not a high bar to clear. For most there, it was their first water quality monitoring event.

This experience was different from my time volunteering with another watershed organization. Granted, I'd never done a winter search, so maybe things are different during the winter. But when we got the buckets with the macros picked up from the river, there was no water in the buckets. We had to pour water in ourselves, which felt weird to me. In my other experiences, you would use a squirt bottle to wash the macros into the bucket. Not a problem, just different.

One problem we did encounter was that it was so cold that the water we put in our ice cube trays was fulfilling its destiny of becoming ice cubes. So the macros got a little frozen. We tried to break up the ice when we noticed it freezing. I wonder if putting more water in the trays would at least slow down the freezing process. I also struggled to see the macros in the harsh sunlight with my transitional lenses. I really should get an alternate pair of glasses for situations where sunglasses are not helpful.

We found three families of stoneflies: the two we set out to find and a third, Perlodidae. Unfortunately, I did not make an observation of the one Perlodidae we found because there were a lot of stoneflies to count and my fingers were freezing in the numbing cold.

However, I did find a few interesting mayfly families and a new-to-me damselfly family (in the nymph stage. I've seen the adults). We found my friend's favorite mayfly family, Heptageniidae. We also found Ephemeridae and Isonchyiidae. When I saw those nymphs, I barely recognized that they were mayflies! They look so different from the ones I usually see. The new damselfly family was Coenagrionidae. We also saw a crayfish. Exciting stuff!

All in all, glad to know that this river is in tip-top shape!

NOTE: This is not an exhaustive guide, and I am not an expert. Just wanting to compile what I've learned. Feel free to correct anything I've said here.

Dipsacus is a genus in the honeysuckle family, Caprifoliaceae. Both species in this guide are introduced to the US from Eurasia. They are two of three species present in the country. The third, D. sativus, is found only on the West Coast, whereas the two in this guide are more widespread.

Flowers

Flower color is not a good determiner of species. Generally, D. fullonum has lavender flowers and D. laciniatus has white, but this is not always the case. See below for some confusingly-colored specimens. Use this as an ID characteristic at your own risk.

D. laciniatus in pink | D. fullonum in white (Thank you @srall !)

Involucral bracts

These are the long, spindly things beneath the flower head. Their thickness, length, and prickle size and density can be good indicators of species.

D. fullonum:

• Narrow, delicate bracts that curve and twist, reaching the top of the flower head or above.
• Prickles are larger and widely spaced. Rarely absent. Occasionally with many smaller prickles between them.

D. laciniatus:

• Wide and short bracts that are more rigid and taper towards the tips.
• Prickles are smaller and usually evenly spaced but densely packed. Sometimes absent or nearly so.

D. fullonum bracts | D. laciniatus bracts

Leaves

There are a few leaf characteristics that can separate these species.

D. fullonum:

• Leaves are always unlobed.
• Leaf upper surface will have at least some prickles that give the appearance of pulled taffy.

D. laciniatus:

• Leaves are sometimes pinnatifid.
• Leaf upper surface lacking any prickles.

D. fullonum w/ unlobed leaves & raised bumps on leaf surface | D. laciniatus with unlobed leaves but lacking the raised bumps | D. laciniatus w/ some pinnatifid leaves & no raised bumps

These are the characteristics I've picked up so far. I'll probably be adding more as I find them. Thank you to @joedziewa for kindly providing most of this information.