Bee health is dependent on good nutrition. Scientists widely agree that four main issues affect honey bee health: forage/nutrition, parasites/pathogens, pesticides, and genetics.
In a healthy honey bee colony, bees get adequate nutrition and have low parasite, pest and pathogen levels. In Washington State, bee health suffers due to:
1) Lack of adequate season-long forage for bees
2) Loss of forage to development and land management practices, and
3) Forage lost to weed control practices