Sometimes they lay eggs before hibernation, but they usually wait till spring. The eggs definately won't turn to workers before hibernation. Good catch, though. Crematogaster queens are quite elusive. I am still yet to find one.
I notice that you are in Chicago. I'm in Naperville. Crematogaster flew here yesterday. I caught about... 40 or so queens. If you need any, let me know. Also caught Lasius. They weren't elusive at all here. They should be cerasi, but some might be lineolata.
Also, the Crematogaster cerasi queen I caught earlier this year had brood. She likely hibernated without brood and laid in spring. That seems to be what they usually do; it took a few months for her to have workers, but my basement is relatively cool.
Edited by Ameise, September 14 2017 - 8:07 PM.