Figure 6

Deformed wing virus titers increased in the honey bee brain with parasitism. Viral titers are expressed as the total number of tags in a sample for each colony individually (Colony 1 and Colony 2). Deformed wing virus (DWV) levels were significantly higher in Varroa-infested bees compared to Nosema- and control bees (Generalized Linear Model with Cox-Reid method for estimating dispersion; Varroa vs. control: P < 0.05, Varroa vs. Nosema: P < 0.01), while increased DWV levels in Nosema-infested bees were marginally significant (P < 0.10). Varroa destructor virus (VDV) titers did not differ between parasitized and control bees (For P-values see Additional file 5: Table S6.)