The state of the antioxidant system of protection of honey bees Apis mellifera carnica under the action of different temperatures in order to optimize the temperature regime to keep of bee colonies indoors during the winter was studied. Bee colonies of 81–91-day-old worker bees were transferred from the territory of the Yuriy Fedkovych Chernivtsi National University apiary during the period of sharp changes in temperature (the end of November) in constant conditions of the buildings (5±0.6°С and 14±0.8°C) and were kept there for 12 weeks. The selection of worker bees for biochemical analysis was performed 7 times every two weeks. The level of TBA-active products (TBARS), catalase (CAT) and glutathione-S-transferase (GST) activity in insect tagmas (head, thorax and abdomen) were studied. It has been found that the transfer of bee colonies from unstable temperature conditions to stable ones, regardless of their value, leads to a decrease in the flow rate of lipid peroxidation (TBRAS level) against the background of increasing activity of enzymes (CAT та GST). The tagmospecific response of the antioxidant system of honey bees depending on the wintering temperature was revealed. Keeping bee colonies indoors at constant temperatures (for ten weeks) was accompanied by certain coherence in the work of the antioxidant system of insects. In particular, the TBRAS level, as well as the activity of enzymes, did not change significantly during the study. However, in early February (at the end of the experiment), regardless of the building temperature, the TBARS level was increased in the tissues of the bee’s head, and in the tissues of the abdomen the GST activity was intensified. At the same time, in the middle of winter (on January), the level of TBARS in bees, that were kept at +5°С, was lower in comparison with bees that wintered at +14°С. The optimal temperatures for keeping bee colonies in winter indoors was proposed: for bee colonies of medium strength at temperatures around +5°С, and for bee colonies of weak strength around +14°С by the end of January with further temperature decrease to +10°С.

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The nutritional composition of rations determines the strength of honey bee families. Feeding with various carbohydrate solutions is widely used in beekeeping. The form of carbohydrate intake in insects can adversely affect their health, leading to redox imbalances. Catalase activity (CAT) is a marker of oxidative stress. It was investigated the catalase activity in foraging bees Apis mellifera during their summer feeding with carbohydrates in the field after grass flowering. The research was perfomed on a private apiary in Chernivtsi region with the local bees (hybrids of Carpathian, Ukrainian steppe and Caucasian breeds). 32 bee colonies, eight experimental groups, were fed various carbohydrates for four days. These are 30 % and 60 % sugar solution, a mixture of honey and 60 % sugar solution (2: 3), without feeding, 30 % glucose and fructose solutions, a mixture of 15 % glucose and fructose solutions (1: 1), a mixture of 30 % fructose solutions glucose (1: 1). Then all bees were fed with 30 % sugar solution. CAT activity was determined in the head, thorax and abdomen of bees by Aebi method with modifications. The highest CAT activity was detected when using 30 % sugar solution for insect feeding. While doubling the sugar concentration and adding honey to the sugar syrup reduced the activity of this enzyme in all bee tagmas. Feeding the colonies with 30 % solutions of glucose or fructose also decreased CAT activity. The cessation of additional feeding decreased the CAT activity in abdomen tissues. It should be noted that the 60 % concentration of sugar, which results equimolar amount of monosaccharides by hydrolysis, differently affects the CAT activity in the tissues of the head and thorax. Decrease of CAT activity is observed on a diet with disaccharide, and this activity does not change on a diet with an equimolar mixture of monosaccharides. At the same time, two fold reducing the sugars concentration (30 % sugar compared to 15 % glucose + 15 % fructose) has the opposite effect – a decrease of enzyme activity in head tissues on an equimolar mixture of monosaccharides and no changes in thorax tissues. Conclusions. It was shown that feeding bee colonies in the period of cessation of the main honey plants flowering with 30 % sugar solution increased the CAT activity in foraging bees. Feeding with 30 % solutions of monosaccharides (glucose, fructose) and 60 % solution of sugar led to decrease of enzyme activity in all studied tagmata (head, thorax, abdomen) of bees. The tagmaspecific responce to various types of a carbohydrate diet in bees was found: in the abdominal tissues of all experimental groups there was a decrease of catalase activity compared to feeding with 30 % sugar solution (preparatory stage), while in the tissues of the thorax and head CAT activity depended on the type of carbohydrate diet. It was demonstrated that the form of carbohydrate intake (disaccharide or equimolar mixture of monosaccharides) affects the CAT activity in the tissues of the head and thorax of insects.

The resistance to stress factors and the health of Apis mellifera colonies depends on many factors, in particular, the nutrient composition of the forage base of bees. The quantity and quality of food components are stress factors that can cause oxidative stress in bees. The purpose of our work is to evaluate the impact of diets with different carbohydrate composition on the development of oxidative stress in honey bees. The impact of different carbohydrate diets (I – 60% honey, II – 30% sucrose, III – 60% sucrose, IV – 30% glucose, V – 30% fructose, VI – 30% glucose + 30% fructose (1:1 )) on the state of the antioxidant system in four- to seven-day-old worker bees in laboratory conditions was evaluated. Determination of biochemical markers was carried out after 24 and 96 hours of keeping bees on diets. It has been shown that the component composition of the diet affects the volume of food consumed by bees, the level of lipid peroxidation (TBARS) and the activity of catalase. Consumption of monosaccharides by bees for 24 hours caused a tagmospecific response of insects depending on the type of hexose. The lowest level of TBARS was found in the head of bees that consumed a fructose diet, and in the abdomen of insects that consumed a glucose diet, compared to bees of all other experimental groups. It is shown that the level of TBARS is not influenced by the concentration of carbohydrates, which bees are able to regulate by changing the amount of food consumed, but by the chemical composition of carbohydrates in the diet. Catalase activity was higher in the head of bees consuming fructose than in bees consuming glucose. a prolonged change in catalase activity was found, which depended on the structure and concentration of carbohydrates. Evaluation of the level of oxidative stress in bees on different carbohydrate diets using the proposed markers showed that glucose is the least nutrient stress factor compared to fructose and sucrose.