-Colony losses of managed honeybees have raised a major concern, and surveys of colony losses were conducted around the globe to understand the apicultural situation. Up to now, most studies have focused on the mortality of the Western honeybee (Apis mellifera ); however, little is known about the mortality of its eastern counterpart-the Eastern honeybee (Apis cerana ). Here, we report the survey results of A. cerana colony losses in three consecutive years (2011-2012, 2012-2013, and 2013-2014) in China. Colony losses were low overall (12.8%, 95% CI 11.9-13.7%) but varied among years, provinces, and types of apiaries. We used generalized linear mixed effects models to estimate the effects of possible risk factors and found that queen problems (queenless or dronelaying queens) were associated with colony losses. Further analyses showed that differences in mortality among different types of apiaries may be contributable to the differences in queen problems. This is the first survey of colony losses of A. cerana .

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For social insects such as the honeybee, olfactory language plays a critical role in colony life, with important functional roles for work within and outside of the hive. According to honeybee biology, newly emerged bees are developmentally immature (Calderone, 1998), and they join a caste that mainly cleans cells while awaiting functional maturity (Winston, 1987). From the ages of 4-12 days (Seeley, 1982), the nursing caste feeds larvae or the queen for about 1 week (Seeley, 1979). Middle-aged bees (12-21 days old) build and maintain the nest, and receive and process nectar (Johnson, 2003, 2008a). After 21 days, workers initiate tasks outside of the nest (foraging nectar and pollen, scouting, defending) (

Studies of adult workers' responses to infected brood were undertaken to isolate discrete volatile compounds that elicited honeybee hygienic behavior. Using a freeze-killed brood assay, we determined that in healthy colonies adult workers recognized and emptied infected cells with a 95% clearance rate. SPME-GC-MS results emptied >95% infected cells indicated differences in the composition and relative content of volatile compounds released by healthy and diseased brood. Additionally, we determined that the main volatile compound released from the pathogen Ascosphaera apis was phenethyl alcohol. The Y-tube olfactometer indicated that 10-to 20-day-old workers of healthy colonies, but only 15-day-old workers of diseased colonies, were significantly sensitive to differences in characteristic volatile compounds. This information could facilitate honey bee selection based on mechanisms that contribute to chalkbrood disease tolerance.

ABSTRACT. Apis mellifera ligustica and A. cerana cerana exhibit differences in olfactory sensitivity to odors from nectariferous plants and diseased broods. It is presumed that the differences in odorant-binding proteins (OBPs) between these 2 species contribute to their olfactory sensitivity. We compared the sequences, temporal expression pattern, and binding properties of the 2 OBP-encoding genes. We cloned the Amobp5 and Acobp5 genes. Among the ligands tested, phenethyl acetate was the most variable, with AcOBP5 showing high affinity and AmOBP5 having no apparent affinity for this ligand. While AmOBP5 had high affinity to both benzyl alcohol and 2-phenylethanol, the binding affinity of AcOBP5 to these compounds was moderate. However, the fluorescence intensity of these compounds was not decreased below 50%; thus, the dissociation Study of the obp5 gene in Apis mellifera and Apis cerana constants could not be calculated. The Amobp5 gene showed significantly higher expression in 10-and 15-day-old workers than in other stages, while the Acobp5 gene had the highest expression in 30-day-old workers. Both the Amobp5 and Acobp5 genes had the lowest expression level in 1-day-old workers. These results suggest that the binding properties and temporal expression patterns of the obp5 genes in A. mellifera and A. cerana play a critical role in the olfactory sensitivity of workers.