There have been many theories about "Varroa infection decline", Recently I read somewhere that insecticides called neonicotinoids is blamed as Varroa destructor. The varroa mite has infected bees throughout the country. Other then Pesticides and loss of habitat is another factor.
However, there are a few things the average citizen can do to help these important pollinators thrive.
* Do not overuse insecticides and read application instructions carefully.
*Let herbs flower; bees love mint, basil and cilantro.
*Avoid spraying roses while they are flowering.
*Plant flowers to attract bees; they are attracted to blue, purple and yellow flowers.
This information may not be very usefull as we control pests such as Bed Bugs, Spiders, Moles, Bees, Hornets, Fleas, Bat etc.
Let me know if you need more information.