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.

Guaranteeing high acaricide efficacy to control Varroa destructor is fundamental for colony survival. In this study, we verified the efficacy and impact of a commercial thymol-based veterinary product (Apiguard®) on colony honey bee populations when used alone or combined with the biotechnical method of caging honey bee queens to create an artificial brood interruption period in the colony. Apiguard® killed 76.1% of the mites while queen caging killed 40.6% of the mites. The combination of Apiguard® administration with queen caging killed 96.8% of the mites. Comparing bee numbers before and after treatment, Apiguard® treated colonies with caged queens had 48.7% fewer bees compared to before treatment, while Apiguard® alone reduced the number of adult bees by 13.6%. None of the treatments in the different groups resulted in elevated queen mortality.

The replacement of synthetic acaricides with organic treatments is a big challenge in modern beekeeping. In summer 2015, we carried out in Central Italy a study to compare the varroacide efficacy and the toxicity on honey bees of the formic acid evaporator Nassenheider Professional^® with two new formic acid-based gel formulations: MAQS^® and Varterminator^®. In the same apiary with 32 colonies, four homogeneous groups with eight hives each were prepared. The mean acaricide efficacy of Nassenheider Professional^® was 73.2 ± 12.5%, while MAQS^® and Varterminator^® showed a mean efficacy of 49.3 ± 14.9 and 81.2 ± 16.0%, respectively. Colonies showed a statistically significant reduction of adult bees only after the MAQS^® treatment with respect to the control group. All the treatments showed absent or quite moderate queen mortality (MAQS^® and in Varterminator^® groups 12.5%, Nassenheider professional^®, and control groups 0%). Our study indicates that Nassenheider Professional^® and Varterminator^® may represent a sustainable and effective solution to control mite infestation during summer in temperate areas.

Nosemosis is a serious microsporidian disease of adult European honey bees caused by the spore-forming unicellular fungi Nosema apis and Nosema ceranae. In this paper we describe the currently known techniques for nosemosis prevention and control including Good Beekeeping Practices (GBPs) and biosecurity measures (BMBs). Topics such as queen renewal, nosema-resistant bees and hygienic and control methods are described. Strong efforts are currently provided to find more a sustainable solution than the use of antibiotics. So far, it seems that the best way to approach nosemosis is given by an “integrated pest management strategy”, which foresees the contemporary application of different, specific GBPs and BMBs.

Prompted by FAO/WHO's and the European Commission's recognition that documents on Good Farming Practices (GFPs) and Good Veterinary Practices (GVPs) in apicultural production are hardly available, part 1 of this contribution provides an update of current apicultural production and associated best practices to ensure animal and public health. Major bee health and disease prevention issues and risk management options at the primary production level are summarised with particular reference to the role of the veterinary practitioner/consultant and the official veterinarian in a control function in the safe production of honey.