ABSTRACT
Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees (Apis mellifera), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeepers and 165 meliponiculturists participated in the 2-year survey (2016-2017 and 2017-2018). On average, 30.4% of honey bee colonies and 39.6% of stingless bee colonies were lost per year across the region. Summer losses were higher than winter losses in stingless bees (30.9% and 22.2%, respectively) but not in honey bees (18.8% and 20.6%, respectively). Colony loss increased with operation size during the summer in both honey bees and stingless bees and decreased with operation size during the winter in stingless bees. Furthermore, losses differed significantly between countries and across years for both beekeepers and meliponiculturists. Overall, winter losses of honey bee colonies in Latin America (20.6%) position this region between Europe (12.5%) and the United States (40.4%). These results highlight the magnitude of bee colony losses occurring in the region and suggest difficulties in maintaining overall colony health and economic survival for beekeepers and meliponiculturists.
Subject(s)
Beekeeping , Seasons , Animals , Bees/physiology , Latin AmericaABSTRACT
Varroa destructor is one of the most important sanitary threats for the beekeeping industry and so far disease control is based mainly on chemical treatment. However, a long-term solution may arise from studying natural surviving colonies of Apis mellifera. We compared the Varroa infestation rate in six commercial colonies that received annual treatment against mites and six non-treated colonies that survived in absence of any treatment for the last 6 years. In addition, we evaluated two potential mechanisms that might be involved in colony survival: hygienic (HYG) and Varroa-sensitive hygiene behavior (VSH) by means of pin-killed and mite artificial infestation, respectively. HYG and VSH were negatively correlated with mite infestation independently of the colony group (treated or non-treated). Furthermore, colonies expressing high levels of pupae removal (≥ 80%) showed higher %HYG and lower mite infestation compared to colonies showing low pupae removal (< 80%). The analysis of reproductive status of mites from the non-removed infested cells evidenced that more infertile mites are found in colonies with more than 80% of pupae removal. To study non-treated colonies that survive for several years, it is a suitable approach for identifying the underlying mechanisms related to Varroa-resistance.
Subject(s)
Mite Infestations , Varroidae , Animals , Argentina , Beekeeping , Bees , PhenotypeABSTRACT
Information on the longterm consequences of Nosema ceranae to honey bee lifespan and effectiveness of Nosema control with fumagillin is scarce and not always consistent. Our objective in this study was to evaluate the effectiveness of the antibiotic fumagillin to control N. ceranae in hives in EastCentral Argentina. Honey bee hives were assigned to 3 experimental treatments, a control group with untreated hives, a preventive strategy group with hives treated monthly, and a monitoring strategy group with hives treated according to a N. ceranae threshold level. Apiaries were monitored monthly during FallWinter 2009 and 2010 and N. ceranae spore intensity and honey bee colony strength measures were estimated. Fumagillintreated colonies had reduced N. ceranae spores load in 2010 compared to control colonies. However, there was no significant difference between treated and control groups for colony strength measures including adult bee population, bee brood availability, honey, or pollen. Fumagillin treatment reduced N. ceranae intensities but had little effect on colonies. The bee population during Winter was reduced in treated as well as in control colonies. Our results clarify that fumagillin treatment should be at least reviewed and that further research should be conducted to acquire a more complete perspective of Nosemosis disease.
