Varroa mites are the bane of honeybees’ existence. They’ve become a huge problem of late, contributing to spread of disease, weakening of colonies, and death of colonies. They’re nasty little buggers, looking like ticks on the bees. Gross.
To keep the mites in check, you need to monitor the mite population in the hive. The population can explode over the summer, severely weakening a colony. And if the colony is too weak going into the winter, they may not survive.
There are multiple ways to estimate the mite population in a hive. One way that’s used a lot is to do a “sugar shake.” You put some powdered sugar in a jar with a screened lid, add a scoop of bees, and shake them around to coat the bees with sugar. The sugar causes the mites to lose their grip on the bees, so you can then turn the jar upside down and shake the mites out through the screen onto a plate or something, then count them. You can just put the bees back into the hive; they’ll clean the sugar off each other. Definitely not happy bees, but they’ll survive. There are other, similar methods that some say are slightly more accurate, but you have to kill the bees to do it.
You’re really supposed to do checks periodically, but especially in the spring to make sure they won’t become uncontrollable over the summer, and again in the late summer to make sure there aren’t too many going into winter. I of course never got around to doing this in the spring when I was supposed to. I still wanted to check the mite levels, but I also didn’t want to disrupt the colony at this point in the year as much as a sugar shake would. So I used another method: the sticky board.
This is just a thin piece of cardboard or the like, sticky on one side. If you have screened bottom boards, all you do is slip the sticky board underneath the hive, wait a few days, then count how many mites have fallen down and are stuck to the board. It’s not necessarily the most accurate method, according to some, but it’s super simple and results in zero disturbance to the colony. And it’s definitely better than no monitoring at all.
The suggested way to do a count is to leave the board on for a few days and get an average number of mites dropped per day. The hard part comes in deciding how many mites is too many, meaning you need to treat the colony to reduce the mite population. There are lots of different numbers out there for the “threshold” number for treatment, so it’s a bit difficult to sort through. It also depends on the time of year, size and strength of the colony, etc. So it seems that it will be one of those things that comes with experience. For this time of year, the “acceptable” number of mites dropped in a day ranges anywhere from 3-12, or even higher.
The total number of mites on the sticky board from Andoria was 22, giving an average daily drop of about 7. (You can see the green marks I made on the board next to each mite.) That’s not too bad, as far as I can tell, though I’ll want to keep an eye on it. The total number on New Vulcan was only 4, meaning a daily average of just over 1. That’s REALLY good. Makes me wonder if I missed a bunch—which is certainly possible, since I’ve never done this before.
I’ll do another check in late summer/early fall and decide about treatment then. Good news for now, anyway!