Piotr Dziechciarz

The virulence patterns observed in viruses transmitted by Varroa destructor implied a potential association of these honey bee pests in Poland with the Korean haplotype. Nevertheless, it is noteworthy that this hypothesis lacked direct verification. Therefore, the aim of the study was to determine the haplotype affiliation of V. destructor mites infesting bees in Poland and Ukraine. Adult females were collected from drone brood from honey bee colonies maintained in the apiary at the University of Life Sciences in Lublin, Poland, and the apiary in Synevyr National Park in Ukraine. The haplotype affiliation was determined through the sequencing of the cytochrome oxidase subunit I gene (CO I; 929 bp) fragment. Based on the phylogenetic comparison with 84% bootstrap support, the V. destructor females from both locations were confirmed to represent three haplotypes: Korean 1 (AmK1-1), Korean 2 (AmK1-2), and Chinese 4 (AmK1-4). They are the most virulent types of this parasite worldwide and in Poland. Concurrently, the present study confirms that the Synevyr National Park in Ukraine is isolated from alien bee subspecies, but is not free from alien parasites.

The aim of the study was to compare the activities of proteases and their inhibitors in the hemolymph of honeybee workers reared in small-cell combs (SMC) and standard-cell combs (STC) in laboratory cage tests. The analyses conducted in laboratory conditions facilitated assessment of the impact of the comb cell width (small vs. standard) along with eliminating the influence of many environmental factors on the results. The width of the comb cells in which the workers were reared had a significant effect on the protein concentrations and proteolytic system activities in the hemolymph. Irrespective of the age of the workers, higher protein concentrations were found in the hemolymph of the SMC workers. In turn, the activities of proteases and their inhibitors in the hemolymph of 1-day-old bees were higher in the STC workers. In older bees, aged 7–21 days, activity was higher in the SMC workers. The role of the considerable cell width variability in natural combs that were built without the use of an artificially produced wax foundation is worth investigating. It is highly probable that the impact of the comb cell width on the features of workers reared in these combs modifies the age polyethism in the worker caste as well. The investigation results of one-season studies of honeybees could be seriously affected by random factors. To reduce the risk of these effects, it is advisable to continue experiments over a few consecutive years.