Yep, once you look in your hive and there are SHB larva in the comb, most all of the bees in that hive leave you will never forget it. Happened to the first hive I had. A fellow gave me the hive and 3 or 4 days latter thats what I had. When the supers are not on I have Fipronil in dvd cases in hives, very few SHBs 0 to 4 per hive. Good luck with yours
Joe