Trochosa ruricola - Trochosa terricola

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… John Rosenfeld, 26 May, 2016 - 8:27pm

Just when I thought ...

I was going to be able to differentiate these from images... looking at "Distinguishing the females of Trochosa terricola and Trochosa ruricola (Araneae, Lycosidae) from populations in Illinios, USA" by Thomas R. Prentice I'd have thought this was T. terricola. Then I see Paquin & Dupérré's (2003) diagrams and they're a lot more similar to each other and I see the note that it's better to ID the females based on the males that are found with them ... but if they're sympatric how is that reliable? Is it the "bird shaped" receptacle that makes this ruricola? I have more reading to do...

… Laura P., 23 May, 2016 - 2:00pm

I based the ID on the fact that

I had found Males here with their hook at the tip of the cymbium and the bump on the chelicerae. I realize the ID is somewhat tentative. I wonder if the two species are actually distinct or if genetic testing would reveal that they are the same. I found another one the other day in a sink in the basement.

Seems to show a fair amount of variability in the epyginum.

… John Rosenfeld, 23 May, 2016 - 2:16pm

I found this ...

in Brady, 1980" "Trochosa terricola forms together with spinipalpis, robusta, and ruricola of Europe a close-knit species group. There is a great anatomical similarity among these species and a definitive study of the middle European species of Trochosa (Engelhardt 1964) did not reveal any ecological, seasonal, or ethological isolation mechanisms present. These four species occur sympatrically throughout western and central Europe. In spite of morphological, ecological, and behavioral similarities, no hybrids could be produced in the laboratory. Engelhardt suggests that physiological mechanisms (pheromones) may prevent hybridization between these species."

Going by "Prentice, 2001" that other one you linked to does look like T. ruricola.

… Laura P., 23 May, 2016 - 2:40pm

I wonder how reliable

the submarginal band on the carapace is, that Prentice talks about. That would be helpful if it was consistent.

… John Rosenfeld, 23 May, 2016 - 3:18pm

I don't know ...

as far as just going on general appearance I think the tawny colored ones that have little to no discernible abdominal pattern aside from a few tiny black flecks can be placed here ... that appearance doesn't seem to necessarily work for the males though ... darker ones are trickier...

Have you looked at the keys here? https://crocea.wordpress.com/2012/05/22/5821/

It's in Norwegian, scroll down to where is says "Nokkel for Trochosa-hunner" for a comparison of T. ruricola and T. terricola ... also the image where is says "vulva-eksempler", shows variability the top row is T. ruricola, the bottom row is T. terricola.

… Laura P., 26 May, 2016 - 5:20pm

I agree

This one does seem to be T. terricola. I'll have to look for a male.

… John Rosenfeld, 26 May, 2016 - 8:33pm

Good luck ...

I hope you find one! Leave it to you to find two such similar species in the same location.

… Laura P., 27 May, 2016 - 9:07am

Isn't that the truth :-)

I seem to have really high diversity index here in my yard. I collect wasps in the genus Gelis for an entomologist in Finland and she has seemed rather shocked at the number of different species I've found.

… John Rosenfeld, 27 May, 2016 - 9:37am

That's awesome.

… Laura P., 27 May, 2016 - 9:40am