Do I really need to monitor?
Yes, you really should. There is a really big difference between hoping that your colony isn't overtaken by mites, and knowing that your bees aren't overtaken by mites. There is also a big difference between looking for mites and monitoring for mites. By the time that you see mites on the bees or in the brood, it is often too late to bring the colony back to health. It is important to monitor to make sure that your management is working, because what worked for you last year may not work for you this year. It is much better to get that information in the fall when you can do something about it than it is to clean up dead colonies in the spring.
What is the best way to monitor for varroa?
You want a method that provides you with usable information - we want to know if our colony has been taken over by the mites, so we want to have a sense of the mites per bee. The only two methods that provide this information are the alcohol wash and the powdered sugar roll.
Methods that don't work:
- Checking drone brood. Some people recommend looking at drone brood to see if you spot varroa, but the info is too inconsistent to be useful.
- Using a sticky inspection board to record drop over a certain amount of time. Inspection boards can be useful to see mite drop after a treatment (if you don't see any dead mites after you put in a Mite Away Quick Strip, then you may have had a bad product or applied it wrong), but the inspection board will not give you a good sense of mites/ bees.
- Just looking for mites. Most of the mites in the hives are underneath the cappings. If they are on bees, their favorite place to be is on the underside of the abdomen, between the scales. Pretty much impossible to spot. By the time you start seeing varroa on your bees, the viruses have usually caused a lot of damage to your colony.
When should I start monitoring?
You want to monitor enough so that you get a sense of when the population of varroa takes off, or when your colony is in danger. The varroa dynamics will depend on the size of the colony and your climate. A big strong colony in an area with no real winter break will have very different risk than a package introduced in a northern climate. Where I live in Michigan, we often see low levels of mites in May, June, and July, and they start to peak in August. If you are new to monitoring, then it is good to start before the risk is high (e.g. May), so that you can learn how to do it well. You want to be able to trust the outcome of your monitoring when it really counts.
How many hives in a yard should I monitor?
At least eight. If you have only a few colonies, then you want to monitor each one. If you have a big yard, then you want to do at least eight so that you capture a range of outcomes. You may have some colonies that had a break in the brood cycle (low risk), and you may have some that robbed out a hive collapsing from PMS (high risk). Usually, by monitoring 8 hives, you capture all of those dynamics and will end up having enough information to make a decision.
How often do I need to monitor?
I recommend monitoring every time you do a full inspection (every 3 weeks). That way you can understand the varroa dynamics in your area. It is also good to monitor before and after you perform any treatments so that you know that they work.
Have more questions about monitoring? Please email them to me, and I'll add them - firstname.lastname@example.org