41st Annual Meeting of the Society for Invertebrate Pathology
and 9th International Conference on Bacillus thuringiensis

RNA viruses are emerging as a serious threat to honey bee (Apis mellifera) health and are suspected as major contributors to the recent malady, Colony Collapse Disorder. Understanding the transmission of these viruses can shed valuable light on the epidemiology of this syndrome. In addition, the recent detection of Deformed Wing Virus in bumble bees as well as some of these viruses in in-hive food reserves of honey bees suggests a possible wider environmental spread of viruses with potential impact on the overall pollinator community. We studied the distribution of viruses in honey bees, their pollen loads and in other non-Apis hymenopteran pollinators collected from flowering plants. All the samples were analyzed with reverse transcriptase-PCR and virus identity was confirmed by sequencing. We report for the first time the molecular detection of picorna-like RNA viruses (deformed wing virus, sacbrood virus and blackened queen cell virus) in pollen pellets collected directly from forager bees. Furthermore, pollen pellets from some uninfected foragers were detected with virus, indicating a potential role of pollen in viral transmission. These viruses were found in eleven other species of native bees and wasps, expanding the known host range of these viruses and suggesting a possible deeper impact on the health of our ecosystem. Sequence comparisons of viruses isolated from honey bees, pollen and other non-Apis hymenopteran species indicate that the viruses are circulating freely among these species. In addition, the Israeli Acute Paralysis virus was detected in non-Apis pollinators near CCD apiaries but not in those near healthy non-CCD apiaries. Our findings increase the understanding of virus epidemiology and may help explain bee disease patterns and pollinator population decline.