Seems to me this would be a great time to treat them as there is no brood in the hives. I was thinking about doing a powdered sugar shake a day or 2 after I hived them, possibly before releasing the Queen. I'm using screened bottom boards. Does anyone have any recommendations on this?
my opinion is that the less you mess with a new package, the better. the brood break that you have with a package is good enough. mite problems don't usually get bad until the second year, and your package provider has probably already treated.
I suppose one could put the package over a sticky board overnight to see if there was any significant mite drop to determine if treatment was required before hiving them. If there was a mite problem I would be inclined to get on the phone with my supplier immediately.
I did not find sugar dusting to be very effective mite control in my bee yard. You might have better luck with it. It makes sense that sugar dusting might be more effective prior to the bees getting on comb, after which there are always bees and mites that don't get dusted cause they are in the cells.
If the hive needed it, seems like in the package would be perfect time for an oxalic acid or other mite treatment...being as there is no brood. Those with experience using oxalic might need to input here.
Good question methinks.
I think most packages have been treated already. I agree with Kathy, the less you mess with them the better off you will be.