Abstract

The world-wide decline in honeybee colonies during of the past 50
years has often been linked to the spread of the parasitic mite,
Varroa destructor (Varroa), and its interaction with certain honeybee
viruses. Recently in the U.S.A. dramatic honeybee losses (colony
collapse disorder) have been reported, however, there remains no clear
explanation for these colony losses, with parasitic mites, viruses,
bacteria, and fungal diseases all being proposed as possible
candidates. Common characteristics that most failing colonies share is
a lack of overt disease symptoms and the disappearance of workers from
what appears to be normally-functioning colonies. In this study, we
used quantitative PCR to monitor the presence of three honeybee
viruses, deformed wing virus (DWV), acute bee paralysis virus (ABPV)
and black queen cell virus (BQCV) during a one year period in 15
asymptomatic, Varroa-positive honeybee colonies in Southern England,
and 3 asymptomatic colonies confirmed to be Varroa-free. All colonies
with Varroa underwent control treatments to ensure that mite
populations remained low throughout the study. Despite this, multiple
virus infections were detected, yet only a significant correlation
between DWV viral load and over-wintering colony losses were observed.
The long held view has been that DWV is relatively harmless to the
overall health status of honeybee colonies unless it is in association
with severe Varroa infestations. Our findings suggest that DWV can
potentially act independently of Varroa to bring about colony losses.
Therefore, DWV may be a major factor in over-wintering colony losses.

http://aem.asm.org/cgi/content/abstract/AEM.02227-09v1?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=VARROA&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

-- 
Juanse Barros J.
APIZUR S.A.
Carrera 695
Gorbea - CHILE
+56-45-271693
08-3613310
http://apiaraucania.blogspot.com/
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