Varroa Mites

[Pharmacyman]

Hi, I have two hives in a residential area. This is year two with them. Last year the person I was learning from came over and used oxalic acid vaporization. I just tested for Varroa and hives were 2% and 2.3%. Should I treat for mites at this level? Would Apiguard be a good choice if I should treat now?

[Jacobs]

You are getting into treatment range. If it were me, I would go with a treatment or two of OAV and do a sugar roll afterwards to see about mite levels. My "go to" for going into winter mite treatments is FormicPro. I like that it kills mites under capped brood, but the downside is that it can be hard on weaker queens. I also like the first 3 days it is in to have high temperatures not greater than 82F. If I am trying to get this done sometime in August, I watch the forecast closely and go to work when the opportunity presents itself. I normally do OAV treatments around December 21st as a matter of routine.

Check the Apiguard label for temperature ranges and limitations on use. You should not have honey supers on using thymol based products, but if you are not planning on taking this honey or if you are feeding sugar water, using Apiguard should not be a problem.

I would suggest that you go to the "Bee Health" link on our homepage at www.guilfordbeekeepers.org It is toward the bottom of the home page on the left hand side. It will take you to the Honey Bee Health Coalition site. This has current information about mite thresholds, and it has a tool for helping you make a decision about what type of mite treatment you may want to use.

[Pharmacyman]

I caught two queenright swarms in my yard this spring and made them into hives. I just tested one using sugar shake method. It turned up no mites! I am used to at least seeing 4 or 5 in a hive. Is this to be expected, that new hives test mite free?

[Jacobs]

No.

[reedyfork]

I second Jacobs' treatment approach - FormicPro in August as temps allow followed by OAV in late Dec.

Rather than sugar rolls or alcohol washes to test, I started using periodic OAV throughout the rest of the year as a means of testing (and treatment). I have all screened bottom boards, so I can watch the mite drop on the IPM boards and get a RELATIVE mite count. It's not meant to be exact, but I can compare and gauge good vs. bad and tell which colonies might need follow-up attention. I have discovered more than one "mite bomb" using this approach! I splurged a couple years ago and bought one of the battery-powered vaporizers, making this task so much easier...

[Pharmacyman]

That's interesting! I need to buy some OAV equipment also. How often during the year do you do the OAV treatments? How long after before you read the IPM board?

I wish more people used this message board. I pick up some good stuff from you guys. Maybe we should announce it at GCBA meetings.

[reedyfork]

The primary OAV treatment is towards the end of Dec., but I usually hit them again in early March (or before honey supers go on) and again in mid-July (after supers come off).

I will try to check after ~2-3 days to see the mite drop. I'm not so exact with that, but the goal for me is just to compare my colonies to each other.

[Jacobs]

I like OAV as an emergency knock down method/lazy beekeeper method of limiting mite damage. My main time to use it is around December 21 (winter solstice/bee "new year"), but if I see DWV in a hive, I am likely to hit it up with at least 1 round of OAV. It doesn't kill mites under the cappings but has no upper temperature limits, can be used with honey supers on, does not appear to have resistance issues, and is well tolerated by the bees.

[Jacobs]

I took advantage of the current weather to get Formic Pro on my Brown Summit hives and the hives at the Cooperative Extension. I'll probably go with Apiguard at the house. I haven't used it before, but will be able to put it on when temperatures climb back up.

[Pharmacyman]

I just inspected one of my last two remaining hives to test for Varroa. This is the one with no mites in July. There were 25 mites today or 8.3%. I was looking for brood frames from which to collect my sample and found absolutely no brood on any frames. Does that sound like a problem this time of year? Should there be some brood? Does this mean it's queenless?

There are a gazillion bees in the hive. I did not see any deformed wings. Is the hive hopeless or should I treat for Varroa? Could I use OA since there are no capped cells.

One other question. I have a deep on the bottom and two mediums. In the deep all cells are empty. Should I take the deep off?

[Jacobs]

My opinions--I would remove the deep if it is totally empty. I would treat with OAV since it is broodless. Your bees may be bringing in mites from a colony that has queen issues and is an object of your bees' robbing efforts. After that, I would keep an eye on the landing board; are the bees flying like the other hive? Are they bringing in pollen? I had a hive that apparently re-queened in September. When I first checked it, there was an unmarked queen and no brood. She has since started laying. If they are foraging and are or start to bring in pollen, I would let it go about a week or 10 days and then look for eggs/larvae. You may still be queenright.

[Pharmacyman]

The hive with the deep and two mediums, no problem. I removed the empty deep (drawn out empty frames) and set it out in front of it's hive. By sunset all the bees in the deep went into the hive. No problem.

The next hive I inspected had a deep and 3 mediums. I found in the deep and one of the mediums no brood and no resources on any frame. I removed both the deep and the medium. All the many bees on the removed deep occupied five of the 8 frames in the box both front and back (lots of bees) and none of them appear to have gone into the hive last night. I checked at about 4pm. today and they are all still there.

What do you think is going on here? What would you do at this point?

[Wally]

I think you need to look again. I think you have a queen and/or brood in that box.

[Pharmacyman]

Thanks, I have decided to check and put that box back on the hive...it has so many bees.

I have an OA vaporizer wand and OA. How much OA should I use per hive?

[Jacobs]

I think label is 1 gram per brood chamber, but studies indicate 4 grams of OA total is more effective than 1 or 2.