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Date: | Sun, 24 Aug 2008 10:11:50 -0400 |
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The changing face of mite infestation in the African Bees of Brazil:
> One factor in the success of AHBs seems to be higher levels of resistance toward mites and pathogens. Understanding the mechanisms for this resistance is important for the continued health of South American beekeeping and could provide more general insights for bee breeding programs. After many years of low disease presence, honey bee populations in parts of Brazil, and especially the southeast region, have shown declines in the past five years, severely impacting beekeepers. These losses are at least superficially similar to enigmatic colony mortality recently seen in the US (e.g., ''Colony Collapse Disorder" or CCD and Europe.
> Mite levels differ across subspecies of Apis mellifera, and the fertility of female mites in AHB worker brood is considered low compared to other subspecies. Nevertheless, recent work suggests that the reproductive ability of Varroa destructor in Brazil is changing. Garrido et al. observed that the fertility rates of female mites have increased in São Paulo and in Santa Catarina state (southeast and southern of Brazil, respectively). While Varroa mite were not a specific focus of the current study; we did find mites in each of the analyzed colonies.
> An evaluation of colonies from this region in 2006 found infestation rates of 10.68 mites per 100 adult bees, on average, and that 9% of worker brood cells contained female mites (152/1700; unpublished data). According to Garrido et al., levels of Varroa mites in Brazil have increased since 1998 and are comparable to European levels. Along with host effects, this increased presence of mites is concordant with the dominance of what is believed to be a more virulent haplotype of Varroa destructor. Higher mite levels could certainly affect virus populations in Brazil, through the abilities of these mites to vector these viruses.
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Virus infections in Brazilian honey bees
Erica Weinstein Teixeira, Yanping Chen, Dejair Message, Jeff Pettis,
Jay D. Evans
Journal of Invertebrate Pathology
ARTICLE IN PRESS
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