Search

Temperatures of worker- and drone-brood rearing in various hive locations were compared in both colonies kept on small-cell combs (4.90 mm) (SMC) and standard-cell combs (5.50 mm) (STC) in two seasons. Temperatures close to the worker-brood comb placed near the rightmost storage-comb were lower than those near the worker brood in the nest centre but equal to those near the outskirt drone-brood comb (34.37-35.24°C) regardless of the month and the comb-cell size. Temperatures of the brood rearing in the SMC did not differ from those in the STC, independently on the location (center-periphery) and the brood type (drone-worker). Occasionally, they were even higher in the STC near the peripheral drone-brood comb and in the nest centre. We concluded that the drones which are involved in colony reproduction could affect its thermoregulation. The peripheral drone brood can be heated just as well as the worker brood, if the colony is strong enough and has the proper drone-worker ratio. Therefore, it is doubtful whether a higher temperature near the worker brood in the SMC limit the development of the V. destructor population. A lower temperature may not be a factor in encouraging V. destructor females to prefer trap-drone-combs for reproduction in the SMC. Strong field colonies may be especially prone to such behaviour. Therefore, temperature cannot be considered a mechanism of effective Varroa control in SMC.

We examined the influence of curcumin-supplemented feeding on worker lifespan, Nosema resistance, key enzyme activities, metabolic compound concentrations and percentage of the global DNA methylation. Two worker groups (Apis mellifera) were set up: 1) control group; workers were fed ad libitum with sucrose syrup; 2) workers were fed with the syrup with the addition of curcumin. Dead workers were removed every two days and the Nosema spp. infection levels were assessed. Hemolymph was taken from living workers for biochemical analyses. The global DNA methylation level was analysed using DNA from worker heads and thoraces. The bees that consumed curcumin lived longer and were less infested with Nosema spp. The curcumin-treated workers had higher concentrations of proteins, non-enzymatic biomarkers (triglycerides, glucose, cholesterol, Mg2+ and Ca2+), uric acid and creatinine, as well as elevated activities of antioxidant enzymes (SOD , GPx, CAT , GST ), neutral proteases, protease inhibitors, enzymatic biomarkers (AST , ALT , ALP ). The concentrations of albumin and urea, and the activities of acidic and alkaline proteases were higher in the control group. Curcumin decreased global DNA methylation levels especially in older bees in which the natural, age-related level increase was observed. Most of the parameters increased over the apian youth and adulthood, and decreased in older bees. The decrease was markedly delayed in the bees fed with curcumin. Curcumin appeared to be an unexpectedly effective natural bio-stimulator, improving apian health and vitality. This multifactorial effect is caused by the activation of many biochemical processes involved in the formation of apian resistance.

The most prevalent rodentborne zoonotic viruses in Europe are hantaviruses, lymphocytic choriomeningitis virus (LCMV), cowpox virus (CPXV), and Puumala virus (PUUV) (1). In 2016, a total of 18 countries in [...]