Honey Bees
Parasitic Mites
There are two types of mites that can be devastating to honey bees: tracheal mites and varroa mites. Varroa mites are the pest you will spend most of your time and effort trying to control. Many treatments for varroa can also help control tracheal mites, and vice versa.
Tracheal Mites
- Suspect if your hive is failing or abandoned despite plenty of honey stores, or if you see bees on the ground with disjointed "K-wings."
- Grease patties made of sugar and vegetable shortening. Some varroa treatments are also effective against tracheal mites.
Tracheal mites are microscopic parasites that infect the honey bee’s trachea, feeding on hemolymph. They can only be officially diagnosed by having a specialist check dead bees. Suspect if your bee population is dwindling, your hive is abandoned with plenty of honey stores, or you see bees on the ground with disjointed “K-wings.”
You can provide your bees with grease patties by mixing 1 part vegetable shortening and 2 parts granulated sugar. Flatten into patties between sheets of wax paper and place directly on the frames of the brood box during the winter (don’t put on the hive when bees are making surplus honey for human consumption). Grease patties may also help control varroa.
Varroa Mites (and Deformed Wing Virus)
- Adult varroa are red-brown and attach to pupae and adults. You may see the mites themselves or evidence of the diseases they carry, such as adult bees with deformed wings. Regular mite checks keep you informed and will guide treatment.
- Multipronged approach... rotate treatments (thymol, formic acid, oxalic acid, etc), powdered sugar, screened bottom boards.
Varroa destructor (also known as Varroa mites) attach and feed on both pupae and adult bees, but they also spread disease. Adult varroa are red-brown and 1-1.8mm long and 1.5-2mm wide. They’re small, but visible to the naked eye. Here is a nice illustration of the varroa life cycle.
They also spread deformed wing virus which affects pupating bees and causes them to emerge with shriveled, misshapen wings. These adults with deformed wings die shortly afterward. This combination of parasitic mites and the deformed wing virus they carry leaves the hive in a weakened state, which increases susceptibility to other pathogens.
All colonies have some varroa, it’s just a matter of keeping their numbers under control. Varroa mites grow exponentially if left unchecked. Prevention and treatment is a multipronged approach. This is the pest you will spend most of your time and effort trying to control.
