Bad news for bumblebees

This post also appears on my main blog but I thought it may also be of interest to beekeepers.

I came across this poor bee while doing my monthly bumblebee count for the Bumblebee Conservation Trust.  It is a newly emerged queen red-tailed bumblebee (Bombus lapidarius).  It was crawling around in the hedgerow, unable to fly.  The reason is obvious as it has no wings, just shrivelled stumps where they should be.

The appearances are very similar to those we see in honey bees affected by deformed wing virus (DWV).  This is the major cause of disease in honey bees and is transmitted by the varroa mite (Varroa destructor).  This photo shows an affected worker honey bee (Apis mellifera) with a varroa mite on its thorax.

DWV is endemic in honey bees but is present in much higher levels in the presence of Varroa infestation.  It is also found in bumblebees.  In 2006 Genersch et al reported wing deformities in Bombus pascuorum and Bombus terrestris affected by DWV.  More recently Fürst et al found DWV to be present in 11% of British bumblebees, with evidence of virus replication in one third of those, suggesting active infection.  Little is known about the prevalence of wing deformities in bumblebees.  They cannot fly and presumably die quickly so they will not be detected by standard surveillance methods.  Bumblebees are not affected by Varroa but they share flowers with honey bees and may well acquire the infection that way.  Most responsible beekeepers treat their bees to help control varroa infections, and thus reduce the levels of DWV, but there is little or nothing that can be done to prevent infection of bumblebees.  I suspect nothing at all is known about wing deformities or DWV infection in solitary bees, although a similar deformity has recently been observed in a Colletes bee.


Fürst MA, McMahon DP, Osborne JL, Paxton RJ, Brown MJF. Disease associations between honeybees and bumblebees as a threat to wild pollinators. Nature. 2014;506(7488):364-366. doi:10.1038/nature 12977.  available here.

Genersch E, Yue C, Fries I, Miranda, J. (2006). Detection of Deformed Wing Virus, a honey bee viral pathogen, in bumble bees (Bombus terrestris and Bombus pascuorum) with wing deformities. Journal of Invertebrate Pathology. 91. 61-3. 10.1016/j.jip.2005.10.002.