The Portland area rolled into September with high heat and no rain in sight. These were likely the last weeks of dry weather before we start to see Fall rains arrive. These can be busy times for beekeepers, readying their hives for the deep Fall and Winter. Our last monthly meeting was full of practical advice! Mandy Shaw, who has served PUB since 2016 provided helpful reminders to the group on how to best prepare. This is a critical time for the developing nurse bees, who will go on to raise our winter bees, who will in turn, raise our spring bees! Three important factors at this time are mite management, providing nutritional support in the form of syrup and pollen patties and equalizing hives for colony strength. At the same meeting we also hosted Ben Sallmann of the Bee Informed Partnership. He shared details on the life cycle of the Varroa mite which we all know to be quite a formidable foe. He recommended spanning mite treatments across a couple of weeks so the treatment kills phoretic mites as well as the ones that hatch out in the following days and weeks with new bees. The Partnership conducts extensive research on mite testing and found alcohol wash tests resulted in 95% of the mites being accounted for. With a sugar roll, only 60% of the mites were dislodged, a discrepancy which could have a significant effect on your treatment decisions. With regard to treatment, Partnership research showed Apivar works better in Spring and will not be very effective on high mite loads. For thymol, two smaller treatments are more effective than one long one. It might kill some open brood, but it’s ok, the queen will fill it out. Formic acid works well for high mite loads but can kill brood/queen in hot weather. Oxalic acid is very effective on high mite loads and is particularly effective in winter. Sallmann recommended a dose of 35g oxalic crystals in 1L of 1:1 sugar syrup and with 5ml dripped in between the frames, as a one time treatment. His recommendation for OA vaporization was that the smoke should be billowing out and under-dosing is a common problem. Vaporization is also best in late Fall through Spring, several days apart. Now get out there and prep those hives!
