1. Troutnut Forum
›
2. Specimen Discussion
›
3. Which species is this?

I'm pretty sure this is Paragnetina. Can anyone who knows that genus well fill in the species?

Jason,

As far as I know, the only species of Paragnetina we have in NY and PA are media and immarginata. The latter, the "beautiful stone," is highly patterned in yellow/black/brown and has very distinctive markings. The markings on this specimen seem somewhat unusual for media. Were it not for what appears to be a complete setal row across the occiput, I'd be inclined toward Acroneuria.

Guys,
I have noticed that several of the pictures on this website are mis-identified. This set of photos is not of Paragnetina at all. There is clearly no occipital ridge. It is true that the only species of Paragnetina found in the State of NY are immarginata and media, but this specimine is clearly Acroneuria sp.

I am also from NY and I am a NABS certified taxonomist. My company offers macroinvertebrate taxonomy workshops for professionals. If anyone is interested in improving their ID skills, have a look at the "Upcoming Workshops" tab of our website. Also, feel free to contact me directly and I'd be happy to point you in the direction of some useful dichotomous keys.

Web: www.rwaa.us
emaial: mlajoie@rwaa.us

-Matt Lajoie
Aquatic Biologist and Taxonomist
Watershed Assessment Associates, LLC

Thanks Matt. Please post correct IDs on any specimens you find misidentified, if you've got time. That's why I built the forum into the main site the way I did, so experts can weigh in on such tricky business.

This is most likely an A. abnormis nymph. The other likely possibilities, A. carolinensis and lycorias are marked differently in several ways that seem to hold up most of the time.

Femora - abnormis has dark longitudinal streaks; carolinensis and lycorias usually have pale bands or blotches.

Pale occiput band - abnormis is usually more uniform in width (and usually thinner) with thin detached commas around the lateral ocelli or absent; carolinensis tapers progressively wider towards the margins with a pair of thick connected dashes adjacent to the ocelli. lycorias usually has a large dark spot intruding into the occipital band in the center making it appear very thin in that location.

"W" mark - abnormis is thin & often broken; both carolinensis and lycorias are usually bold.

Dorsal habitus - generally, abnormis is darker overall and doesn't usually have the contrasting abdominal banding often obvious on the other two.

A. lycorias can be easy to confuse with carolinensis as their markings can be very similar in the nymphal stage. Fortunately, lycorias usually has obvious anal gills lacking in the others.