Massive Honey Bee Die Off
Varroa mites harbor virulent virus that weaken and eventually kill honey bees. Varroa mites have become resistant to amitraz, the only remaining widely used miticide for hives. Amitraz was widely used, but no longer is considered effective at controlling Varroa mites in honey bee hives.
The Varroa mite is an external parasitic mite that attacks and feeds on honey bees. The Varroa mite is one of the most damaging honey bee pests in the world. A significant mite infestation leads to the death of a honey bee colony or hive, starting in late autumn through early spring. Often hives become weak over the winter and the honey bee population in a hive is decimated by spring. Without management for Varroa mite, honey bee colonies typically collapse within 2 to 3 years in the USA.
The Varroa mite can reproduce only in a honey bee colony. It attaches to the body of the bee and weakens the bee. The Varroa mite is a bee parasite and causes the most economic damage. The United States just endured the worst-ever honey bee colony collapse, with 62% of commercial colonies perishing between June 2024 and January 2025. Every mite tested in the st
dy showed resistance to the Amitraz chemical. This is a major concern for U.S. agriculture, which depends on bees to pollinate more than 90 crops and generates up to $30 billion annually.
USDA researchers found that the viruses likely delivered the fatal blow, but factors like pesticide exposure and poor nutrition may have left bees more vulnerable. With amitraz resistance becoming widespread and new treatments years away, experts warn that beekeepers are running out of viable tools. The article reference is listed below: Thompson, J. (2025, June 30). Scientists identify culprit behind biggest ever U.S. honey bee die-off. Science, 389(6756).
Bee keepers can reduce mite numbers by monitoring to avoid bee hive losses. If 3% of a bee hive is infested, this is considered the economic threshold where damage is high enough to require more management. Screened bottom boards on hives can be used for both monitoring and mite removal. Mites prefer drone comb which can be used as a trap to remove mites from the hive. Some honey bee lines in breeding programs also show partial resistance to Varroa mites. Good bee hive cleaning is always recommended as an additional management strategy.
The association of the Varroa mite with a virus that protects the mite from a miticide is not new. It is something called Trophobiosis (rather large complicated word) which means one species protecting another species for mutual gain, usually “protection for food”. For example, ants protect aphids or mealy bugs in exchange for food. The ant protects and farms the aphids or mealy worms from predators in exchange for sugar excrement called honey dew. Other examples include Ants and larvae where ants tend and protect larvae of specific insect species for mutual gain. In Beetles and Fungi, certain beetles share food with certain fungi for mutual gain.
In the Varroa mite and virus situation, the roles are reversed. The virus protects the Varroa mite from the miticide in exchange for a home (food) in the Varroa mite body. Both the Varroa mite and the virus prosper while the honey bee weakens and dies off. Usually there is also a nutritional angle to this story. In the case of the bees, poor bee pollen or poor food sources also weaken the bees. Often this is due to chemicals or pesticide use. Examples include using 2-4D on wheat which often results in a flare up of Greenbug infestation. Using atrazine on sugar cane often results in a flare up of Yellow Sugar Cane Aphids. While pesticides and chemicals can help in one situation or against a pest, sometimes they weaken the plants ability to fight off another pest.
Healthy plants have the ability to fight of diseases, pathogens, parasites, and especially insects if they grow at a fast rate. Insects can not consume whole proteins so they ignore healthy plants. Less healthy plants have what is called “incomplete photosynthesis” where because a certain or combination of nutrients are lacking, the plant can not produce complete proteins. This causes the plant to be less healthy and opens the plant up to insect infestations. Insect wounds then create a place for diseases, pathogens, and parasites to enter. For the bees, plants, animals, and humans; staying healthy often starts with good nutrition.
