Molecular detection and seasonal variation of deformed wing virus affecting honey bee, Apis mellifera L. colonies
S. A. Dar and Sandeep Kotwal
A survey was conducted on a geographic scale of Kashmir valley for the detection of Deformed Wing Virus (DWV) using RT-PCR and specific primers. Samples of adult bees and pupae were collected from 20 apiaries in 5 different locations in the spring, summer and autumn seasons were screened for the presence of DWV during 2012-13. In the present investigation, Deformed Wing Virus (DWV) was found in 80% of the apiaries and infection was increased from spring to summer during the year both in adults and pupae, but decreased in autumn as colony brood declined. The recorded DWV frequency in the spring and summer was 37 and 65% respectively, but in autumn, it was 32%. In pupae, it was 16, 26 and 7% respectively. As a whole, higher virus frequency was detected in brood populations (92%) than adult populations (90%). The present findings support the role of Varroa mite in transmitting the virus. This was the first report on detection of DWV in honeybee colonies in Kashmir valley. Taken together, the data indicated that DWV occur persistently in bee colonies since 2005.