TY - JOUR
T1 - Prevalence and infection intensity of Nosema in honey bee (Apis mellifera L.) colonies in Virginia
AU - Traver, Brenna E.
AU - Fell, Richard D.
N1 - Funding Information:
We thank Drs. Judy Chen and Jay Evans (USDA Bee Laboratory, Beltsville, MD) and Dr. Tom Webster (Kentucky State University) for providing known samples of N. ceranae and N. apis, We thank the Virginia beekeepers for participating in the survey and submitting samples. We also thank members of the Fell laboratory for technical assistance. This project was funded in part from the Virginia State Beekeepers Association.
PY - 2011/5
Y1 - 2011/5
N2 - Nosema ceranae is a recently described pathogen of Apis mellifera and Apis cerana. Relatively little is known about the distribution or prevalence of N. ceranae in the United States. To determine the prevalence and potential impact of this new pathogen on honey bee colonies in Virginia, over 300 hives were sampled across the state. The samples were analyzed microscopically for Nosema spores and for the presence of the pathogen using real-time PCR. Our studies indicate that N. ceranae is the dominant species in Virginia with an estimated 69.3% of hives infected. Nosema apis infections were only observed at very low levels (2.7%), and occurred only as co-infections with N. ceranae. Traditional diagnoses based on spore counts alone do not provide an accurate indication of colony infections. We found that 51.1% of colonies that did not have spores present in the sample were infected with N. ceranae when analyzed by real-time PCR. In hives that tested positive for N. ceranae, average CT values were used to diagnose a hive as having a low, moderate, or a heavy infection intensity. Most infected colonies had low-level infections (73%), but 11% of colonies had high levels of infection and 16% had moderate level infections. The prevalence and mean levels of infection were similar in different regions of the state.
AB - Nosema ceranae is a recently described pathogen of Apis mellifera and Apis cerana. Relatively little is known about the distribution or prevalence of N. ceranae in the United States. To determine the prevalence and potential impact of this new pathogen on honey bee colonies in Virginia, over 300 hives were sampled across the state. The samples were analyzed microscopically for Nosema spores and for the presence of the pathogen using real-time PCR. Our studies indicate that N. ceranae is the dominant species in Virginia with an estimated 69.3% of hives infected. Nosema apis infections were only observed at very low levels (2.7%), and occurred only as co-infections with N. ceranae. Traditional diagnoses based on spore counts alone do not provide an accurate indication of colony infections. We found that 51.1% of colonies that did not have spores present in the sample were infected with N. ceranae when analyzed by real-time PCR. In hives that tested positive for N. ceranae, average CT values were used to diagnose a hive as having a low, moderate, or a heavy infection intensity. Most infected colonies had low-level infections (73%), but 11% of colonies had high levels of infection and 16% had moderate level infections. The prevalence and mean levels of infection were similar in different regions of the state.
UR - http://www.scopus.com/inward/record.url?scp=79953786422&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79953786422&partnerID=8YFLogxK
U2 - 10.1016/j.jip.2011.02.003
DO - 10.1016/j.jip.2011.02.003
M3 - Article
C2 - 21345338
AN - SCOPUS:79953786422
SN - 0022-2011
VL - 107
SP - 43
EP - 49
JO - Journal of Invertebrate Pathology
JF - Journal of Invertebrate Pathology
IS - 1
ER -