Parasite - #1 of 6 stressors by reach
A pinhead-sized external parasite, Varroa destructor, that feeds on the fat body of adult bees and developing brood while spreading deformed-wing and other viruses.
Of the 6 stressor categories USDA tracks, Varroa mites is the 1st-most reported, touching 27.3% of U.S. colonies last quarter. Here's where it concentrates, how it moves through the year, and which pollination crops walk hives into it - all from public USDA aggregates.
USDA asks beekeepers each quarter what share of their colonies each stressor touched. For varroa mites, here are the states reporting the heaviest load this spring - measured against the U.S. average.
Share of each state's colonies reporting varroa mites (2025 Q2), against the U.S. average of 27.3%. Tap a state for its full profile.
Varroa mites is not steady through the year. Six straight quarters of real USDA readings show the spring surge that lands right when colonies are trucked in for pollination.
Share of U.S. colonies affected, six straight quarters of USDA readings.
Pollination contracts walk hives straight into local conditions. This ranks every tracked crop by the varroa mites load across its growing states - a colony-weighted read of what a hive meets at each bloom.
Colony-weighted varroa mites load across each crop's growing states, vs the U.S. average. Tap a crop for its profile.
Derived Colony-weighted average across the growing states USDA reports for each crop. USDA measures stressors by state, not by crop.
Every category USDA tracks. Switch to any of them.