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There is growing concern that massive loss of honey bees can cause serious negative effects on biodiversity and ecosystems. Surveys of colony losses have been performed worldwide to monitor the dynamic changes and health status of honey bee colonies. Here, we present the results of surveys regarding winter colony losses from 21 provinces in China from 2009 to 2021, with a total of 1,744,324 colonies managed by 13,704 beekeepers. The total colony losses were low (9.84%; 95% Confidence Interval (CI): 9.60-10.08%) but varied among years, provinces, and scales of apiaries. As little is known about the overwintering mortality of Apis cerana, in this study, we surveyed and compared the loss rates between Apis mellifera and A. cerana in China. We found colonies of A. mellifera suffered significantly lower losses than A. cerana in China. Larger apiaries resulted in higher losses in A. mellifera, whereas the opposite was observed in A. cerana. Furthermore, we used generalized linear mixed-effects models (GLMMs) to evaluate the effects of potential risk factors on winter colony losses and found that the operation size, species, migration, migration×species interaction, and queen problems were significantly related to the loss rates. New queens can increase their colony overwintering survival. Migratory beekeepers and large operations reported lower loss rates.
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An efficient protocol for the synthesis of γ,δ-unsaturated α-chloroketones has been developed via Au-catalyzed tandem intermolecular hydroalkoxylation/Claisen rearrangement. In the presence of 1 mol% JohnPhosAuCl and 1 mol% NaBArF, a broad range of allylic alcohols smoothly underwent the tandem intermolecular hydroalkoxylation/Claisen rearrangement with aromatic, vinylic or aliphatic chloroalkynes to give structurally diverse γ,δ-unsaturated α-chloroketones in excellent yields. Importantly, high Z/E selectivity was achieved. Other advantages are widespread availability of the substrates, compatibility with a broad range of functional groups and mild reaction conditions.
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BACKGROUND: Honey bee (Apis mellifera) drones and workers show differences in morphology, physiology, and behavior. Because the functions of drones are more related to colony reproduction, and those of workers relate to both survival and reproduction, we hypothesize that the microclimate for worker brood is more precisely regulated than that of drone brood. METHODOLOGY/PRINCIPAL FINDINGS: We assessed temperature and relative humidity (RH) inside honey bee colonies for both drone and worker brood throughout the three-stage development period, using digital HOBO® Data Loggers. The major findings of this study are that 1) both drone and worker castes show the highest temperature for eggs, followed by larvae and then pupae; 2) temperature in drones are maintained at higher precision (smaller variance) in drone eggs and larvae, but at a lower precision in pupae than the corresponding stages of workers; 3) RH regulation showed higher variance in drone than workers across all brood stages; and 4) RH regulation seems largely due to regulation by workers, as the contribution from empty honey combs are much smaller compared to that from adult workers. CONCLUSIONS/SIGNIFICANCE: We conclude that honey bee colonies maintain both temperature and humidity actively; that the microclimate for sealed drone brood is less precisely regulated than worker brood; and that combs with honey contribute very little to the increase of RH in honey bee colonies. These findings increase our understanding of microclimate regulation in honey bees and may have implications for beekeeping practices.
Asunto(s)
Abejas/fisiología , Pupa/fisiología , Animales , Abejas/metabolismo , Humedad , Larva/metabolismo , Larva/fisiología , Masculino , Microclima , Polen/metabolismo , Pupa/metabolismo , Reproducción/fisiologíaRESUMEN
Honeybee (Apis mellifera) royal jelly (RJ) has a long history in human medicine because of its health-protecting properties. To develop a fundamental and comprehensive understanding of lipids in RJ, this article reviews the available literature on lipid compounds identified from RJ extracts and in vitro pharmacological effects of 10-hydroxy-2-decenoic acid in RJ and other closely related compounds, some of which are also identified as lipid compounds in RJ. Overall, the lipids in RJ are composed of mostly (aliphatic) fatty acids, almost all of which are present as free fatty acids and scarcely any as esters. Most fatty acids in RJ are medium-chain fatty acids, whether hydroxylated in terminal and/or internal positions, terminated with mono- or dicarboxylic acid groups, and saturated or monounsaturated at the 2-position. Besides these fatty acids, lipids in RJ contain sterols in minor amounts. Lipids in RJ are useful as preventive and supportive medicines with functionalities that include potential inhibitors of cancer growth, immune system modulators, alternative therapies for menopause, skin-aging protectors, neurogenesis inducers, and more. Taken together, the evidence suggests that health-protecting properties of RJ can be, in part, ascribed to actions of lipids in RJ.