Varroa Mite has been the prevalent cause of many bee deaths. For fall wrap up, going into winter, you need to make sure to check for varroa and treat your hives accordingly. There are various ways to treat Varroa Mite and treatments can differ depending on the season. In this blog we will cover what a Varroa Mite is and what fall treatments to use.
What’s the Varroa Mite?
A parasitic mite that requires a honey bee as a host to survive and reproduce. The entire life cycle of the varroa mite is spent in the bee colony. The mite can only reproduce in the brood, and spreads through the hive via close contact between the bees. Female mites are the ones to feed on the adult bees, while the males will feed on the larvae and pupae. Female mites will attach themselves on the bee’s abdomen and will feed on the haemolymph (equivalent of blood/fat). By riding the bee, the mite can spread quickly to new areas and affect other honey bee colonies. Varroa life span can vary anywhere between 25 days to 5 months. During the summer the mite can live up to 3 month and complete 3-4 breeding cycles.
As you can imagine, if this pest is left untreated it can be lethal to your hives. This is why you should always test for mites in spring, early summer, and fall. You can do so by washing your bees in a counter mite jar using dish soap, windshield washer fluid, or rubbing alcohol. Check out this video on how we do our tests. If you do one wash and there’s no mites, follow up with another wash as the first may be inconclusive. If you do find mites you’ll want your levels to be less than 0.5% by the end of season. The percentage is found through the following calculation after you count how many mites came out from the wash:
Mite Count/300 bees x 100 = percentage of mites
Types of treatments?
There are two types of treatments for the Varroa mite. Formic Pro strips and Oxalic acid. These two treatments are very different from one another and target different areas of your hive.
Formic pro is used in early fall when the temperatures are still warm (10C - 29C). It targets the brood portion of your hive where it will penetrate into the capped brood cells and kill the mites where they reproduce. This ensures that the emerging winter bees will have as little to deal with as possible.
Oxalic Acid is usually administered to the hive in the late fall, when there’s as little brood as possible. This is due to the fact that this treatment focuses on the adult bee itself. Oxalic acid is usually used together with a vaporizer that heats it up and then is placed inside the hive. For more information on how, please see our video. The vaporization sends tiny crystals into the air that attach to the surfaces in the hive. These crystals then come into contact with the bees, exposing the mite to the solution. This effectively kills the mite. For more information on how to perform this treatment correctly check out our blog, Varroa Mite Treatments, or you can watch our video here .
Check your provincial apiculturist websites for recommendations on different treatments and when to apply them. We encourage all beekeepers to have an Integrated Pest Management Plan to monitor your colonies and manage your treatments.
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DAN
October 17, 2022
GREAT THANK YOU