2012-01-24
Chemical hive treatment temporarily worsens viral infections
Honey bee with varroa mite on its back. Photo: Barbara Locke
Honey bees are often attacked by varroa mites that also transmit viruses to the bees. The chemical used against the mites, appears to render bees more susceptible to deformed wing virus infections, according to new SLU research published in the journal Applied and Environmental Microbiology.
In theSLU-study, they treated six bee colonies with an acardicide (tau-fluvalinate) for six weeks (the standard treatment duration) and left three control colonies untreated, monitoring mite infestation and virus levels weekly.
Contrary to the investigators’ hypothesis, the viral infection worsened in the treatment group immediately following acaricide treatment.
“This initial increase was seen in all bee stages, including pupae that never were in contact with mites,” says Barbara Locke.
“Thus, we interpreted it to be a possible direct effect of the acaricide, making the bees more susceptible to virus infection,” possibly due to either “debilitating direct effects of tau-fluvalinate on honeybee physiology and/or immune system responses,” she says.
The virus infections ultimately dropped, slowly, due to reduced transmission by the mite.
”However, even at the end of the mite removal treatment, we still recorded substantial infection levels.”
Press photo
Honey bee with varroa mite on its back. Photo: Barbara Locke
Contact information
Barbara Locke, barbara.locke@slu.se, +46 18 67 25 64
Eva Forsgren, eva.forsgren@slu.se, +46 18 67 20 83
Ingemar Fries, ingemar.fries@slu.se, +46 18 67 20 73, +46 70225 37 79
Joachim R. de Miranda, joachim.rodrigues.de.miranda@slu.se, +46 18 67 24 37
Written by:
Nora Adelsköld