Experiments were conducted in three apiaries to assess the comparative efficacy of: Thymovar (Andermatt BioVet AG); Apiguard (Vita Europe Ltd., UK); an oxalic acid solution (OA) which consisted of 2.9% oxalic acid and 31.9% sugar in water; and amitraz fumigation, for controlling the honey bee mite Varroa destructor. Mite mortality increased significantly (p<0.001) in the Thymovar, Apiguard, OA or amitraz treated colonies. The relative mite mortality after: four OA applications, two Thymovar or two Apiguard applications during August and September in the Senično apiary was 41.80% (±14.31), 14.35% (±10.71), and 18.93% (±13.56), respectively. In the control, i.e. untreated colonies, the mite natural mortality was reduced by 3.10% (±3.50). In the Bohinj apiary, two Apiguard applications and a single amitraz treatment resulted in reducing the mite populations by 19.71% (±12.61) and 23.89% (±14.25), respectively. At the Mediterranean located apiary of Vipava, the Thymovar and Apiguard treatments trigged 59.02% (±17.28) and 46.50% (±13.33) of the total mite reduction. In the Vipava apiary, colonies treated with any miticide during the brood period presented no difference (P>0.05) in efficacy. The results indicate that OA, Thymovar, Apiguard or amitraz fumigations are of limited use during the brood periods.
In this three-year-trial study, we examined the quality of mated queens based on morphological and physiology traits. At each location, sister queen bees were reared each year from one Apis mellifera carnica breeder queen. Queens were also reared and mated in different locations. Altogether, we sampled and analysed 324 queens from 27 apiaries in 2006, 288 queens from 24 apiaries in 2008, and 276 queens from 23 apiaries in 2010. Nine queens from each apiary were sampled and dissected for morphological analyses and Nosema ceranae (N. ceranae) spores, if present, were quantified. Three queens from each apiary were prepared and tested for four viruses: acute bee paralysis virus (ABPV), black queen cell virus (BQCV), deformed wing virus (DWV), and sacbrood virus (SBV). The highest average queen weight of 209.49 ± 9.82 mg was detected in 2008. The highest average ovary weight of 78.67 ± 11.86 mg was detected in 2010, and the highest number of ovarioles was 161.59 ± 8.70 in 2006. The average number of spermatozoa in queens ranged from 3.30 x 106 in 2006 to 5.23 x 106 in 2010. Nosema ceranae spores were found in queens sampled in 2008 and 2010. Viruses were discovered sporadically during the queen testing periods from 2006 - 2010. This study importantly demonstrates that queens from rearing stations require regular evaluation for morphological and physiological changes as well as for infection from harmful pathogens. These results could also be used in establishing relevant commercial standards for rearing quality queens.
Two microsporidian species, Nosema apis and Nosema ceranae, infect honey bees (Apis mellifera) worldwide. They are obligate intracellular parasites that multiply in the epithelial lining of the bee’s midgut and cause nosemosis. N. ceranae infections were primarily found in Apis cerana and raised interest in the last decade with the discovery of their presence in the European honey bee (Apis mellifera). Nosema spp. utilizes hosts’ energetic reserves for the purpose of propagation and disrupts the digestive processes of the bee. Nosemosis reduces the lifespan of a single bee and affects the performance of the colony. It also has an economic impact through the reduction in the honey and pollen yield of severely infected colonies or even causes them to collapse. Lack of effective therapy for nosemosis is of special concern and calls for scientific attention. Although N. ceranae and N. apis are similar in many aspects, there are important differences between them such as clinical signs of infection or the ability to resist low temperatures.
Jorge Rivera-Gomis, Ales Gregorc, Andrea Maroni Ponti, Francesco Artese, Gertruida Zowitsky and Giovanni Formato
The Small Hive Beetle (SHB), Aethina tumida, is an invasive pest of honey bee colonies that causes significant damage to the beekeeping sector. SHB was detected in southern Italy (EU) in 2014 and despite adopted eradication measures, is still present there. After three years of observations of SHB in Calabria (2014-2016), we provide here some practical tips for improving control measures. A new time-saving colony examination method, including the use of an internal divider reduced the time needed for hive inspections by 31.86 % on average. Prioritizating the inspection of pollen and honey combs rather than brood combs is advised. Sentinel apiaries with no more than five colonies without supers are suggested for each beekeeping location in order to attract and to monitor the early appearance of SHB. The use of these methods will enable early detection and prompt control measures application before this destructive pest can spread in the region.