Sources: USDA Agricultural Research Service releases on honey bee colony collapses (2025) and new Varroa mite treatments (2026); explained here for home gardeners.
Honey bees had one of their worst years on record, and USDA scientists now have a clearer picture of why. Their research points to viruses spread by a parasitic mite that is becoming resistant to a key treatment, and a new laboratory study suggests a possible way to restore that treatment’s power. Here is what happened, and why gardeners have a real part to play in supporting pollinators.
What happened to the bees
In early 2025, commercial beekeepers began reporting severe losses. According to the USDA, more than 60 percent of commercially managed colonies had been lost since the previous summer, around 1.7 million colonies, with an estimated financial impact of $600 million.
USDA researchers sampled bees and colonies from California and other western states and found high levels of three viruses in the bees they tested: deformed wing virus A and B, and acute bee paralysis virus. These viruses are spread by the Varroa mite, a parasite of honey bees. When the scientists examined mites from collapsed colonies, they found signs of resistance to amitraz, one of the most widely used mite treatments, in virtually all of the mites collected. The researchers also cautioned that viruses are likely the end-stage cause of colony death, and that other long-known stresses on honey bees still matter.
A possible way forward
In a 2026 laboratory study, USDA and University of California, Davis researchers tested a way to make amitraz more effective. They combined it with a research compound that blocks one of the ways mites protect themselves from pesticides, and found the combination increased amitraz’s toxicity, even against resistant mites. The researchers describe this as a proof-of-concept that may lead to new treatment products in the future. They also noted that the compound they used is not specific to mites and can affect honey bees’ own ability to tolerate pesticides, so more research is needed before anything like this reaches beekeepers.
What this means for gardeners
Most gardeners do not keep bees, and Varroa mites are a problem of honey bee colonies, not of gardens. But every garden is part of the pollinator landscape, and well-fed bees are better able to cope with stress. Honey bees and native bees together pollinate many of the fruits and vegetables we grow, including squash, cucumbers, melons, berries and fruit trees.
- Plant flowers that bloom from spring to fall, so bees find food all season. Our guide to planting a pollinator garden includes a sample bed plan.
- Include native plants, which also support the many native bee species that pollinate gardens.
- Avoid spraying pesticides on open flowers, and if you must treat a pest, choose the least toxic option and apply it in the evening when bees are not foraging.
- Provide shallow water with stones for bees to land on.
- Leave some bare ground and plant stems for native bees to nest in.
- If you keep bees, monitor mite levels regularly and follow current guidance from your state’s Extension apiculture program on treatment and rotation.
Flowering herbs, cut flowers and perennial borders all help. See our guides to starting a flower garden and growing a cut flower garden for bee-friendly plants.
Why it matters
The USDA estimates that crops requiring bee pollination are worth more than $20 billion a year in the United States. Research on mites and viruses will shape how beekeepers protect their colonies in the years ahead, and gardens full of diverse flowers give all pollinators, managed and wild, a better chance of thriving.