Diagnosis and distribution of the Apis mellifera filamentous virus (AmFV) in honey bees (Apis mellifera) in China

Pre-screening of samples detected the presence of Apis mellifera filamentous virus (AmFV), a DNA virus that was previously confirmed to be in Apis cerana cerana colonies in several provinces in China. To study whether it was presence and prevalence in A. mellifera colony in China, we collected samples from 170 colonies across 17 provinces and to assess the occurrence and geographical distribution of AmFV in different regions. The highest prevalence occurred in Beijing (80%) among all positive provinces, and the lowest infection prevalence occurred in Fujian and Qinghai with 10%. There was significantly geographical distribution of AmFV infection among investigated regions, and north of China was significantly higher than south of China (p < 0.05) and central of China (p < 0.05). The low infection rate for AmFV was in south of China, southwest and central of China, suggesting that geographical characterization that might favor the presence of AmFV. Although the significance of AmFV infection is not fully understood, its presence may be one of the critical factors affecting honey bee health in China.