Gary,
Stemming the larval growth cycle might help later, but it means you already have an issue in the hivethat the bees aren't taking care of.
Someone from the local club posted information to our group's list that said frames with larva can bestood out in the sun and let the sun dehydrate and kill the larva, then return the frames to the hive. Idid this once with good result with a hive that had been knocked off its stand and the frames not properlydefended by the bees for several days.
Advice has originated with a group from the south, though from upstate NY most things are south (yes, wellaware of our list members in Canada, most/many places, not all).
Best defense is always a strong hive, perhaps easier said than done.
I can pull the specifics of the email if you'd like, not sure I want to or should repost someone else's repostto the list as a whole.
Brian

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html