Great job Bob!!! Feed them plenty of sugar water.......
Bob is in WI.
Here in WI have plenty of forage as we speak for the rest of the summer (mb a couple week dearth in August IF too hot and dry).
No need to feed and worry about feeding UNLESS you have 3-4 non-stop rain days in front of you AND the swarm has no stores yet (then maybe).
OR you have nothing around you but corn fields - then you have more serious sustainability issues.
Well, they will take your sugar water but this would be the least of my worries, seriously.
Feeding swarms in WI in June/July is basically waste of your time.
Find something better to do (urgent building few temp hives/nuc boxes would be one such thing).
Re-hiving - re-hive as soon as practical if you have them in the cardboard box.
Else they will just start building combs directly in the cardboard box.
In similar instances I shake free-hanging swarms directly into nuc hives (always have spare nuc boxes exactly for this need - swarm collection).