I released this queen this morning in a flower pot and she instantly died in the sunlight which was strange. I thought she was just warming in the sun at first, very strange. Anyway this give me chance to properly key her and I found out she is Lasius mixtus
Ah cool, I was going to say it was hard to tell but she looked like Chthonolasius sp. to me.
What pegged her as mixtus vs. umbratus, rabaudi or meridionalis?
Yer cool to find something different. No standing hairs on cheeks or gaster I think makes her Lasius mixtus.
That characteristic sounds familiar from somewhere but I can't remember where. The keys I can find here and here only cite standing hairs on the scape and tibia, though looking at some pictures on antweb it looks like the characteristic of the cheek hairs could stand up too, however there's only one mixtus queen available. This one covering Chthonolasius across Europe also only checked scape and tibial hairs.
Also, man, antweb has so many keys available that I didn't realise about! Go to a genus page like the Lasius one and search through the references, lots of keys and, more importantly, a lot of the PDFs hosted on the website so you don't need journal access.
Not that it makes any difference but the queen was smaller than the usual Lasius umbratus I have found and lacking the reddish/brown colour. Kinda through me off as never found one before. Unfortunately I have not found any Lasius umbratus this year so far.
Huh, I found so many L. umbratus in Buckingham the other week.
Ah, I was looking for that one earlier in the year and couldn't find it. I trust Mike's judgement of course (he's the one that confirmed my L. umbratus ID for me) but I find that key a bit weird for Chthonolasius queens. It splits off L. rabaudi with cheek hairs when every other paper says only reliable characteristic differentiating the queens from L. umbratus is the very distinctive flattening of the scape. It also suddenly stops with "anyway so you've either got one of these five species" when I know you can use scape and tibia to split off umbratus from jensi and meridionalis at least.
I am thinking as well though, you said she just dropped dead in the sunlight? If I recall L. mixtus is one of the ones that has crazy cold tolerance, apparently queens are happily active at 5°C and sometimes overwinter outside the nest and invade colonies in early spring. I wonder if anyone's looked into the heat tolerance of these queens?