Most Varroa induced colony losses occur during the autumn or winter season as a consequence of an elevated Varroa infestation level and an insufficient health status of the adult bees. Even with an initial low Varroa infestation in early spring, critical mite and virus infection levels can be reached before winter if colonies continuously rear brood throughout the whole season. To overcome this challenge, beekeepers can artificially interrupt brood production by suitable management procedures, depending on their type of beekeeping operation. To assess their efficacy, associated workload, and impact on colony development, different methods for brood interruption (queen caging with the combination of oxalic acid treatment, total brood removal, trapping comb technique) were tested during two seasons in 11 locations on 370 colonies in 10 European countries. A protocol was developed to standardize the methods’ application across different environmental conditions. The efficacy of queen caging depended on the mode of oxalic acid application and ranged from 48.16% to 89.57% mite removal. The highest efficacies were achieved with trickling a 4.2% solution (89.57%) and with the sublimation of 2 g of oxalic acid (average of 88.25%) in the broodless period. The efficacy of the purely biotechnical, chemical-free trapping comb and brood removal methods did not differ significantly from the queen caging groups. We conclude that a proper application of one of the described brood interruption methods can significantly contribute to an efficient Varroa control and to the production of honey bee products meeting the highest quality and food-safety standards.

Several negative factors contribute to a decline in the number of insect pollinators. As a novel approach in therapy, we hypothesize that the EM^® for bees could potentially have an important therapeutic and immunomodulatory effect on honey bee colonies. The aim of our study was to evaluate its impact on honey bees at the individual and colony level. This is the first appliance of the commercial probiotic mix EM^® PROBIOTIC FOR BEES in honey bees as economically important social insects. The sugar syrup with 10% of probiotic was administered by spraying or feeding the honey bee colonies in the field conditions, in order to evaluate the infection levels with spores of Nosema spp. and colonies’ strength. Moreover, in laboratory-controlled conditions, in the hoarding cages, adult workers have been fed with sugar syrup supplemented with 2.5, 5, and 10% of EM^® for bees for biochemical and immunological analyses of hemolymph, and with 5 and 10% for measuring the size of hypopharyngeal glands. It was found that following the EM^® for bees administration the Nosema spp. spore counts in colonies were significantly reduced, and colonies’ strength was increased. The results at the individual level showed significant positive physiological changes in treated groups of adult bees, revealing at the same time a higher mortality rate when feeding sugar syrup supplemented with the probiotic.

Various factors contribute to a decline in diversity and number of bees. Here, an integrated approach in experimental BPC 157 therapy was implemented, combining laboratory-controlled and field study results. The aim of a study was to assess the effects of BPC 157 additional feeding of newly emerged worker honeybees on few biochemical and immunological parameters in hemolymph (glucose, trehalose, lipids, proteins, vitellogenin, glucose-oxidase (GOX)), and hypopharyngeal gland (HPG), in laboratory-controlled conditions. Additionally, to examine the physiological status of protein digestion, the enzymatic activity of leucine aminopeptidase (LAP) in the mid-guts of worker honeybees was analyzed. It was found that individual honeybees, in hoarding cages, following BPC 157 administration through carbohydrate food, showed positive physiological changes when compared to the control groups. Those results were complemented by strong and visible LAP activity, particularly noticeable in the apical parts of the epithelial cells in the mid-guts of young worker honeybees originated from treated hives, suggesting a link between alternative oral therapy with BPC 157 and honeybees’ immunity.