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This paper describes the temperature and population distribution in the nest hill of the wood ant Formica polyctena. Calorimetric and manometric data on the heat production of ants, pupae, and nest material were used to estimate their possible contribution to the heat balance of the nest hill. The pattern of isothermal lines in the nest did not fully correspond with the population distribution. Oxygen consumption and heat production of the worker ants and pupae steadily with arising ambient temperature. Investigations of the nest material showed a rapid increase in oxygen consumption in spring and a slower decrease in autumn. From spring to autumn the heat production of material from the center of the nest was higher than that of peripheral material. Heat production of the nest material originates in microbial activities and is chiefly the result of aerobic metabolism. The mass—specific heat production of ants is clearly higher than that of nest material. However, considering the total mass of the nest, the rate of heat production of the nest material is more than seven times the heat evolved by the ants. The seasonal fluctuation in the heat production of nest material coincides well with the active phase of the ants. It is conceivable that the nest materials is aerated and loosened by the building actions of the ants, and thus enough nutrient material and optimum conditions are available to the microorganisms.

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Objective: Energy homeostasis results from a balance of food intake and energy expenditure, accomplished by the interaction of peripheral and central nervous signals. The recently discovered adipokine nesfatin-1 is involved in the central control of food intake, but whether it also participates in the regulation of thermogenesis is unknown. Methods: Nesfatin-1 was administered intracerebroventricularly to freely moving, male Wistar rats and direct calorimetry was performed to assess its effects on thermogenesis. Furthermore, food intake was measured and hypothalamic and N. tractus solitarius (NTS) neuropeptide expression was determined by quantitative real-time polymerace chain reaction. Leptin, which is involved in both the regulation of food intake and thermogenesis, was used as positive control. Results: For the first time it was shown that central nervous administration of nesfatin-1 profoundly increases thermogenesis in rats to a similar extent as leptin and the role of both peptides in the control of food intake was confirmed. Nesfatin-1 significantly downregulated neuropeptide Y (NPY) mRNA expression in both hypothalamus and NTS. Conclusions: The results strongly support the prominent role of nesfatin-1 for both energy expenditure and food intake and NPY neurons appear to be involved in this effect.

-The action of propolis (bee glue) against the ectoparasitic mite Varroa destructor Anderson and Trueman has been investigated and showed narcotic and lethal effects. Length of narcosis and rate of mortality depended on the extraction procedure, concentration of propolis and contact time. Propolis extracted with 70% ethanol was found to be highly toxic, a 10% (w/v) propolis resulting in 100% mortality with a brief contact time of 5 s. In addition, the effect of propolis on the metabolic rate of the mites has been investigated calorimetrically. Even sublethal propolis concentrations without varroacidal effects and of only short lasting narcotic effects resulted in a significant reduction in the heat production rate, indicating weakening of the mites. Varroa destructor / varroatosis / varroacides / propolis / Apis mellifera / calorimetry

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