AdamD wrote: ↑
13 Jun 2019, 11:56
In fact many beekeepers treat too late in the year. With the treatment taking a month and then 3 more weeks before bees emerge after treatment, September is not the time.
I'm afraid I'm guilty of treating for varroa late in September, through October and sometimes into November.
No choice in the matter, as my bees don't come back from the heather moors until 2nd or 3rd week of September.
Too cold for apiguard so OA (Apibioxal) vaporisation for most; although I sometimes use amitraz strips in my most distant apiary to save me a 20 mile round trip every 5 days.
Up here I find many queens take a brood break on the heather (often nowhere for them to lay with nectar piling in).. So they don't seriously start laying their winter bees until late September around these parts.
But if using apiguard then August is usually the last month when day time temps are high enough for it to be effective...And I wouldn't be treating in August anyway as the bees that haven't gone to the heather are piling the Himalayan balsam nectar in until early Sept.
.Even if the temps where compatible with apiguard I'd bin it anyway.. as it has very variable results....