Infestation in large established colonies is very significant this year according to NBU.
Beware of relying on natural mite drop or the Beebase varroa calculator as indicators of numbers of mites.
One of my colonies on 14 x 12 with a natural drop of less than 5 a day in September, when brood numbers are decreasing and you would expect a higher proportion of phoretic mites, has dropped approximately 4,000 mites during three weeks of Apilife. Many of my friends are reporting similar.
As an aside there is little to support the protective effects of sugar dusting and small cell size.
Varroa was not a problem last year...many have become complacent.
A good ongoing IPM which can include sugar dusting/drone culling/chemical control should keep on top of things.
||That's worrying although mine are new colonies. The bee inspector visited just after I had removed a varroa board with very little on it. He was happy with what he saw and I didn't do another treatment. I hope he was right.|
||The mild winter last year probably didn't help.|
I will oxalic in the winter to mop up.
I'm looking into vaporising which looks much less "upsetting" for the bees than opening up and dousing them with syrup.
||Well I've just treated mine with oxalic acid. I didn't disturb them much, those in the topbar barely noticed me. Maybe as I become more confident I will treat them differently but for now I am thrilled that they are doing well. I did put fondant on them a month or so ago which has been more or less ignored by those in the topbar. Clearly I am overwintering several mice though.|
||They're probably ones from your house using it as a holiday cottage.|
||Well, touch wood and all that...|
||I don't know much about top bar hives, but in 'conventional' hives it is usual to put a mouse guard on the entrance in the autumn. My stop your little friends using it as a winter holiday cottage.|
You may find the bees will have killed them by spring. I haven't treated any hives since last spring.
They where hail & hearty at the end of the summer so I will treat with thymol once the weather has warmed.
Saturday was cold, gray and windy here (SE) but I took the top off the hive, slipped another bag of fondant in and closed up. I saw no signs of activity at all. We then spent the afternoon at our local apiary hefting, maintenance and feeding and saw quite a lot of bee activity. I started to worry.
This morning was dry, clear and bright, much warmer than recently and no wind, still no bees and I convinced myself I had lost them. An hour later the hive was covered in sunbathing and buzzing bees. They looked happy and were flying well, I am so relieved and so happy they are still here. I could never have imagined being so upset about insects
||I am always very relieved to see mine. Can't understand how I can be so absorbed watching tiny insects flying in and out of a hole.|
||Our bees by the house were flying yesterday. Probably cleansing flights after having been huddled up in the hive to keep warm over the last week or so.|