After being shown to reduce gut parasitism in bumble bees, a new study highlights the benefits of sunflower for honey bees against varroa mites!
https://entomologytoday.org/2023/01/10/sunflowers-reduced-varroa-infestations-honey-bees/
Sunflowers Linked to Reduced Varroa Mite Infestations in Honey Bees

A new study indicates a benefit to honey bees of local sunflower cropland. Even low levels of sunflower acreage nearby correlate with reduced Varroa mite infestation in managed colonies, researchers found, and supplemental sunflower pollen helps ward off the mites, as well.

Entomology Today