Hasarius adansoni or Evarcha laetabunda ?

[Victor Finchuk]

Ukraine, Rivne region, on April 14.
Small male, about 4 mm. Found on a pine stump at the edge of a pine forest.
Unfortunately, a good photo could not be taken.

[Benjamin Fabian]

Hi Victor,

I guess a free living Hasarius adansoni can be more or less excluded for this region. My first thought was Evarcha. I would exclude E. falcata and E. jucunda anyway. With those 4 bright dots in the posterior half of the opisthosoma it could be a subadult male of E. arcuata. But I only have experience with these 3 Evarcha species and can therefore not exclude Evarcha laetabunda or Evarcha michailovi.

That's all I can say. But I'm sure others can tell you a bit more about your specimen.

Best,
Benjamin

[Victor Finchuk]

The paradox is that I used to find Hasarius adansoni in nature near the site of this find:
https://forum.arages.de/index.php?topic=23870.0
I meet males of E. arcuata relatively often, but they are all very different - they are just black with white stripes under the eyes.
But the version of Evarcha laetabunda seems probable to me, if not confused by the female, also found in nature:
https://forum.arages.de/index.php?topic=23955.msg144349#msg144349

[Benjamin Fabian]

Hi Victor,
all these additional links confuse me a lot.

https://forum.arages.de/index.php?topic=23870.0
I'm not sure whether the photos of this thread are sufficient to give a certain ID. The opisthosoma is way too dark to see any patterns except for the 4 white dots.

https://forum.arages.de/index.php?topic=23955.msg144349#msg144349
If this is a Hasarius adansoni I'll eat a broom.
For me that's an Evarcha, mostly because of the longitudinal black stripe in the center of the anterior opisthosoma. Hasarius adansoni doesn't have such a black stripe. In Hasarius it should be quite the opposite: it should be a bright stripe that is flanked by darker patches.

These two threads are no evidence for me that you have a free living Hasarius adansoni population in this region.

Since you wrote "Small male, about 4 mm" I thought you had a closer look on the pedipalps. But you are right, even young Evarcha arcuata males should be much darker. When I compare your specimen with my observations of Evarcha arcuata, it comes close to what I think is a juvenile female of this species: https://www.inaturalist.org/observations/72159244

I might be wrong, though. Micha has much more experience than me. Let's hope he sees this thread.

Best,
Benjamin

[Victor Finchuk]

I'm not sure the male in the photo is just a guess.
Let's wait for what Michael will say ...

[Michael Schäfer]

I had already seen the post, but was unsure, so I didn't reply until now. In addition, juveniles are difficult to determine. They all don't look 100% like Evarcha to me. However, I am not really familiar with the spider fauna of Ukraine either. Possibly the species varies somewhat there. This is also the case with other species, which have such a range from Europe to Asia.

For me, views of the frontals would indeed be interesting for all of these specimens. Maybe next time you can collect the spider and examine it more closely.


Regards
Micha

[Victor Finchuk]

Well, I'll look. Thank you for your comments.