Varroa mites are ectoparasites that feed off the fat bodies and hemolymph of bees, suppress the immune system, and vector viruses. Introduced to North America from Asia in the 1980s, Varroa mites are considered the most deleterious pests to modern beekeeping. Methods to control mites include chemical treatments, practices that interrupt the mite's life cycle, and utilizing mite resistant honey bee genetics.
Nosema is a prevalent, microsporidian parasite, derived from two different species, that resides in the digestive tract of honey bees and causes dysentery, weakened survival, and reduced honey yield. The fungal spores spread through grooming, food sharing, and cleaning contaminated brood.
American Foulbrood is the most serious brood disease that inflicts honey bee colonies, causing colony collapse and readily spreading to other colonies in the apiary. The spore-forming bacteria kills larvae in their capped cells, which often appear sunken and discolored. Spores can linger for decades if equipment is not eradicated properly. American Foulbrood is a reportable disease. If you suspect AFB, please contact Brooke Decker, the state bee inspector. European Foulbrood is less fatal than the former. The non-spore forming bacteria kills larvae before they are capped. It is common in early spring and may even clear up if left untreated.