Responses of three genetically different stocks of the honeybee to a virus from bees with hairless-black syndrome

Test samples, each of 50 honeybees (Apis mellifera), from three different stocks (hairless-black resistant, hairless-black susceptible, and commercial) were fed over a 3-day period a total dose per bee of 4 × 10⁹, 4 × 10⁷, 4 × 10⁶, 4 × 10⁴, or 0 virus particles in sucrose syrup. Mortality differences due to dose and stock variables were observed. By the last day of the experiment, mortality in control groups of all three stocks averaged less than 4%, whereas samples of susceptible, commercial, and resistant stocks receiving 4 × 10⁹ virus particles per bee averaged 94, 60, and 40%, respectively. The responses to other doses reflected the same trends.