Starting Myrmica tends to be difficult. Live or pre killed fruit flys should work, just make sure that they are wingless. Pre killed will make it easier for the queen, but it doesn't really matter. I think I read something about someone who raised different Myrmica queens, some with pre killed, and some with live. The prekilled ones progressed faster, but it is not scientifically proven.
Give your queen an out world as this will cause less stress during feeding. And you won't have to worry as much about an escaped queen during feeding. Make sure that she is foraging. Don't check on her too much.
Also, are you sure that she is Myrmica Rubra? There are no Myrmica Rubra in New Jersey. Ant Web states that the only Myrmica sp. in New Jersey are Myrmica Punctiventris and Myrmica Spatulata. There is a small chance you could have also mistaken your queen for an Aphaenogaster sp. if you don't have much experience with
https://www.antweb.o...tes&images=true
Oh, and watch out! These ants have a nasty sting!
Your possibles queens. A pic would help review their ID.
Myrmica Punctiventris:
Credits:
https://bugguide.net.../1019629/bgpage
Myrmica Spatulata:
Can't find a queen pic, but here's some info on them.
http://www.antwiki.o...rmica_spatulata
I know Myrmica Rubra is invasive in some areas of the USA but I don't think NJ is one of them
I hope this helped and good luck with your queen!