The ongoing battle with Varroa continues. This is always on my mind, and 2018 was a watershed year for hive losses.
Randy Oliver suggests that, contrary to our wishful thinking, it may be the Varroa mite that outflanks our bees and becomes more virulent over time. I hadn’t considered this scenario—I guess I’m guilty of having a pollyannaish viewpoint regarding this matter.
Something else to consider. If you recall from my January tips, I shared Russell Heitkam’s 2018 loss prediction at 50 percent. For 2019, he predicts a 75 percent loss. Why? He ranks exceeding the carrying capacity as the #1 reason, followed closely by the Varroa mite. I think these two factors are interchangeable and related. It is interesting to note that the Heitkams are reducing their hive numbers by about 25 percent. The kernel of wisdom here is that fewer may be better, and to be a good neighbor. Mite bombs are definitely not appropriate. Regarding carrying capacity, it may not necessarily be more bees but dwindling habitat.
What To Do in July
I will be forthright and share with you exactly what I am doing this year, followed by typical suggestions.
What I’m Doing: I’ve had mediocre success with thymol and formic, to put it mildly. (I haven’t used thymol in over a decade; really bad first experience, may be better now, not qualified to make inputs on thymol products.) I have not used Amitraz in years. I’ve been using oxalic a lot more, in part because, unlike thymol and formic, it has never hurt my bees. During the winter, I vaporized oxalic. Beginning this spring, I again started using the glycerin/oxalic shop towels. Incidentally, they seem to make good queen excluders, for a while anyway. I still believe you want bees that chew up the towels. I think this is how the oxalic is disseminated. (Carolyn Breece said OSU is going to do an oxalic study this summer, hurrah!) I told Jordan Dimock that my litmus test for a breeder queen is: Do they shred the towels up? It seems to be a measure of hive productivity, too. When I walk up to my most productive and voluminous hives, I see pieces of blue shop towels at the entrances.
I’m also raising queens again—now in the month of June. My plan is in part to requeen undesirables and to have backup queens available if I use treatments that are notorious for causing queen losses, e.g., formic. Incidentally, an hypothesis I have heard as to why formic is so hard on queens is that formic masks queen pheromone, and then the workers kill her. It fits. I used Formic Pro last fall, perfect conditions, and it knocked off way too many hives—some of my best. My most severe losses have always been from mite treatments! Plan to requeen if necessary if you use formic, or remove the queen prior to its application.
Here’s an idea for people with just a few hives if you plan to use formic. Remove the queen prior to application. Place her in a nuc box, no capped brood—just honey, pollen, and drawn comb mostly. Shake a bunch of bees from frames with brood if you leave the nuc box at the location (very similar procedure to making a queen cell starter). Apply formic to the main hive with all that capped brood, and oxalic (dribble, vaporization, etc.) to the nuc to kill the phoretic mites. Reunite the nuc and the main after the formic treatment is done and removed.
Boiler Plate July Tips: July brings the end of the nectar flow and the beginning of dearth.
Extra supers should be removed. By the end of July/beginning of August, all supers should be off; hives configured for winter.
It is important to do mite sampling to get an idea of your infestation rate. This is the time of year when the rate of bee reproduction declines and the rate of Varroa reproduction increases. This underscores the importance of knowing whether or not you need to treat. It may be important to treat in July and not wait until August.
I believe it is recommended to treat at only a 1 percent infestation rate, which would correspond to three mites out of a 300 bee sample. Don’t rely on my info, read next sentence. The Honey Bee Health Coalition website has a “Tools for Varroa Management” section. It covers sampling, treatment thresholds, pros and cons of different treatment options for the time of the year. This would be a good resource to use to plan your mite attack.
When the nectar dries up in your area, robbing season begins. Try to prevent robbing—don’t let it start. Reduce entrances on weaker hives; this is absolutely necessary if you’re feeding to build still.
Ensure your hives are queenright while queens are still available.