High resistance to Sacbrood virus disease in Apis cerana (Hymenoptera: Apidae) colonies selected for superior brood viability and hygienic behavior

Sacbrood virus (SBV) caused significant colony collapse in Korean Apis cerana. Therefore, breeding of resistant bees to counter this viral disease is urgently needed. Considering that hygienic behavior in honey bees confers colony-level resistance against brood diseases, we utilized this trait for selecting A. cerana colonies. In addition, the brood survival rate was evaluated after colonies were SBV-inoculated. Over four selective generations, dead brood removal and brood survivorship in selected colonies were higher than those in the controls, which were not selectively bred for those traits (P < 0.01, 99.3 vs. 89.9% for removal of pin-killed pupae; P < 0.01, 99.0 vs. 63.9% for removal of SBV-killed larvae; and P < 0.01, 70.0 vs. 9.2% for brood survivorship). Following SBV inoculation, selected colonies showed an increase in the number of surviving pupae and adults, whereas control colonies collapsed mostly. Our results confirm the feasibility of selecting SBV-resistant A. cerana.