When was the last time you checked for a queen? Did you have a robber screen on? I once mistook all the activity for a healthy, busy hive, but it was unwanted guests and my hive was dead. All the activity was bees from someone else's colony.

First of all, I’m sorry for your loss.  It is both sad to lose a hive and unusual to lose three at once.  My very first hive absconded on me in December of my first year, leaving a hive chock full of honey.  I pulled out all the frames, laid them on the garage floor and took pictures.  I sent these to Ramesh Sageli’s group at OSU for an analysis. The lab’s diagnosis was that my bees had probably absconded because of mites.  They were probably right because I hadn’t treated for mites.  I didn’t even know one should treat for mites.  My mentor at the time told me he had observed the bees at the hive entrance and hadn’t seen any mites on the them as they entered the hive, so he didn’t recommend treatment. 

Since that first loss, I have had other hives abscond on me.  (None, I hope, because I failed to treat for mites.)  One absconded, I believe, because I let the hive temperature get too hot during a long stretch of hot days.  One absconded because I changed the hive configuration, moving a colony from a four over four resource box to a ten frame hive box. I’ve read that swarms are particularly prone to absconding, especially in the first days after you’ve captured them.  My point is that there are a lot of different conditions that may prompt your bees to abscond.  Without more information, it would be difficult to even guess the reason in your case. Here are some of the questions I would be interested in:

• 1.       You said you treated your colonies for mites.  What did you treat with and when did you treat?  (You said August. When in August?)
• 2.      Did you follow the treatment recommendation on the package.  e.g., temperature parameters.
• 3.      Did you sample for mites before and after your treatment?  What were your numbers?  (I ask this because I treated with Apivar in August. My number for one hive was 3 at the beginning of treatment and 43 at the end.)
• 4.      What’s you yellow jacket situation? Skunks?
• 5.      How are your hives situated relative to the weather? Are they protected from rain or wind? Do they get sun? 
• 6.      Did you feed your bees?  (You said there was honey.  How much?  How close to the cluster?) 

These questions are just off the top of my head.  I would challenge other readers of the forum to ask additional questions to help develop a picture of your hives’ situation.  

I see that some readers have already brought up robbing.  I would say that’s a good possibility.  But, the fact that  you lost three hives, including your stronger hives might point in a different direction.

Chuck: I'm not saying that the cause of the loss of your hives wasn't robbing, it's just that you haven't mentioned evidence of robbing.  It has been my experience that when a hive is robbed out, there is always evidence left behind, such as ragged frames of cells where the robbers have chewed into the foundation to get at the loot.  There's dead bees left over from the battle between the home colony and the robbers.  There's shredded wax below the hive or the landing board (robbers are messy and in a hurry to get in and get out with the booty.)  Is any of this evident around your hives? 

In answer to you questions Ted,  I treated the hives using oxalic acid vapor mid-August after removing the honey supers.  I had two hives in a covered area and one about 100yds away from the other two in the open.  I don't thing skunks were the problem since the hive boxes were in tact.

As mentioned before, robbing could have certainly been a factor since I was using the entrance feeder bottles, and saw yellow jackets around the hives but I guess I naively assumed they weren't in sufficiently large numbers to wipe out all three.    I don't know.

I'd like to thank all who offered suggestions and wished I had done more proactively to save this project.

Both of my colonies got robbed out as well. Mite counts were low in July (2% alcohol wash) until they weren’t (in August). The mite growth was explosive! I treated OAV four times on five day cycle. Too little, too late as the colonies could not defend.

So, I’m busy prepping for next spring with six new colonies. Packages and TVBA nucs. Will TVBA have nucs on offer? Are members limited to how many they might buy?

My main question today is about Drone frames as an IPM tool. My understanding is that one places a single drone frame in the bottom box then replaces it every three weeks with an empty. The full one goes in the freezer to kill the mite infected drone larvae. If I understand the theory correctly, this breaks the brood cycle on the most mite-desired drone brood and helps keep mite numbers from exploding. Timing is critical and OAV is still required.

Has anyone any opinion or insights on this method of IPM? Thanks, and, Merry Christmas to all!