Sugar concentration influences decision making in<em> Apis mellifera</em> L. workers during early-stage honey storage behaviour

Decision making in honeybees is based on in- formation which is acquired and processed in order to make choices between two or more al- ternatives. These choices lead to the expression of optimal behaviour strategies such as floral constancy. Optimal foraging strategies such as floral constancy improve a colony’s chances of survival, however to our knowledge, there has been no research on decision making based on optimal storage strategies. Here we show, using diagnostic radioentomology, that decision mak- ing in storer bees is influenced by nectar sugar concentrations and that, within 48 hours of col- lection, honeybees workers store carbohydrates in groups of cells with similar sugar concentra- tions in a nonrandom way. This behaviour, as evidenced by patchy spatial cell distributions, would help to hasten the ripening process by reducing the distance between cells of similar sugar concentrations. Thus, colonies which ex- hibit optimal storage strategies such as these would have an evolutionary advantage and im- prove colony survival expectations over less efficient colonies and it should be plausible to select colonies that exhibit these preferred traits

Managed honey bee colony losses in Canada, China, Europe, Israel and Turkey, for the winters of 2008-9 and 1009-10

In 2008 the COLOSS network was formed by honey bee experts from Europe and the USA. The primary objectives set by this scientific network were to explain and to prevent large scale losses of honey bee (Apis mellifera) colonies. In June 2008 COLOSS obtained four years support from the European Union from COST and was designated as COST Action FA0803 – COLOSS (Prevention of honey bee COlony LOSSes). To enable the comparison of loss data between participating countries, a standardized COLOSS questionnaire was developed. Using this questionnaire information on honey bee losses has been collected over two years. Survey data presented in this study were gathered in 2009 from 12 countries and in 2010 from 24 countries. Mean honey bee losses in Europe varied widely, between 7-22% over the 2008-9 winter and between 7-30% over the 2009-10 winter. An important finding is that for all countries which participated in 2008-9, winter losses in 2009-10 were found to be substantially higher. In 2009-10, winter losses in South East Europe were at such a low level that the factors causing the losses in other parts of Europe were absent, or at a level which did not affect colony survival. The five provinces of China, which were included in 2009-10, showed very low mean (4%) A. mellifera winter losses. In six Canadian provinces, mean winter losses in 2010 varied between 16-25%, losses in Nova Scotia (40%) being exceptionally high. In most countries and in both monitoring years, hobbyist beekeepers (1-50 colonies) experienced higher losses than practitioners with intermediate beekeeping operations (51-500 colonies). This relationship between scale of beekeeping and extent of losses effect was also observed in 2009-10, but was less pronounced. In Belgium, Italy, the Netherlands and Poland, 2008-9 mean winter losses for beekeepers who reported ‘disappeared’ colonies were significantly higher compared to mean winter losses of beekeepers who did not report ‘disappeared’ colonies. Mean 2008-9 winter losses for those beekeepers in the Netherlands who reported symptoms similar to “Colony Collapse Disorder” (CCD), namely: 1. no dead bees in or surrounding the hive while; 2. capped brood was present, were significantly higher than mean winter losses for those beekeepers who reported ‘disappeared’ colonies without the presence of capped brood in the empty hives. In the winter of 2009-10 in the majority of participating countries, beekeepers who reported ‘disappeared’ colonies experienced higher winter losses compared with beekeepers, who experienced winter losses but did not report ‘disappeared’ colonies

CSI pollen: diversity of honey bee collected pollen studied by citizen scientists

A diverse supply of pollen is an important factor for honey bee health, but information about the pollen diversity available to colonies at the landscape scale is largely missing. In this COLOSS study, beekeeper citizen scientists sampled and analyzed the diversity of pollen collected by honey bee colonies. As a simple measure of diversity, beekeepers determined the number of colors found in pollen samples that were collected in a coordinated and standardized way. Altogether, 750 beekeepers from 28 different regions from 24 countries participated in the two-year study and collected and analyzed almost 18,000 pollen samples. Pollen samples contained approximately six different colors in total throughout the sampling period, of which four colors were abundant. We ran generalized linear mixed models to test for possible effects of diverse factors such as collection, i.e., whether a minimum amount of pollen was collected or not, and habitat type on the number of colors found in pollen samples. To identify habitat effects on pollen diversity, beekeepers’ descriptions of the surrounding landscape and CORINE land cover classes were investigated in two different models, which both showed that both the total number and the rare number of colors in pollen samples were positively affected by ‘urban’ habitats or ‘artificial surfaces’, respectively. This citizen science study underlines the importance of the habitat for pollen diversity for bees and suggests higher diversity in urban areas

Trophallactic interactions in the adult honeybee (Apis mellifera L.)

Trophallaxis, the transfer of food by mouth from one individual to another, occurs among adults of honeybee colonies. The drones and the queen consume but do not donate, while the workers are recipients and donors. They share the content of their crops and sometimes the products of their head glands. Such trophallactic interactions can frequently be seen non-randomly between all members of the colony. Their occurrence and success depend on factors such as sex and age of the consumers and donors, food availability and quality, time of day, weather and season. For the youngest workers, old workers, drones and the queen this flow - especially the flow of protein - has definite nutritional importance, since these bees need protein but have only a limited capacity to digest pollen and consume none or only small amounts of it. The system of trophallactic food flow and the existence of a specialised group, the nurses, who are responsible for consuming pollen and processing it as easily digestible jelly enables the colony to have many members with a reduced digesting capacity. The food storer bees specialise in transporting harvested nectar within the hive, receiving it from foragers near the entrance and depositing it in other parts of the hive where it is processed into honey. This saves time and helps the foragers to harvest available food sources more efficiently. In addition to its nutritional value and the importance of transfer to specialists, receiving and donating food in the trophallactic flow of food provides information to colony members about the quality and quantity of food existing in the hive and can therefore be compared in its importance with the dance language and communication by pheromones. © Inra/DIB/AGIB/Elsevier, Pari

Nutrition and health in honey bees

Adequate nutrition supports the development of healthy honey bee colonies. We give an overview of the nutritional demands of honey bee workers at three levels: (1) colony nutrition with the possibility of supplementation of carbohydrates and proteins; (2) adult nutrition and (3) larval nutrition. Larvae are especially dependant on protein and brood production is strongly affected by shortages of this nutrient. The number of larvae reared may be reduced to maintain the quality of remaining offspring. The quality of developing workers also suffers under conditions of larval starvation, leading to slightly affected workers. Larval starvation, alone or in combination with other stressors, can weaken colonies. The potential of different diets to meet nutritional requirements or to improve survival or brood production is outlined. We discuss nutrition-related risks to honey bee colonies such as starvation, monocultures, genetically modified crops and pesticides in pollen and nectar

Inner nest homeostasis in a changing environment with special emphasis on honey bee brood nursing and pollen supply

To reproduce successfully, a honey bee colony has to rear brood efficiently. This requires a fecund queen and depends on the coordinated activities of workers in brood care, in foraging, and in maintaining inner nest homeostasis. Maintaining homeostasis involves thermal regulation of the brood area and providing a steady supply of nutrients, which requires building food reserves during favorable weather so that the brood can be well fed even during times of low nutritional influx. The workforce of adult bees is appropriately divided among the required tasks, and the wax comb itself is spatially organized in a way that saves energy and supports brood nursing. The ability to achieve this homeostasis results from a set of individual behaviors and communication processes performed in parallel by thousands of bees. In this review, we discuss these proximate individual mechanisms that lead to the precise regulation of the complex system that is a honey bee society

Differences in drone and worker physiology in honeybees (Apis mellifera)

Drones and workers have completely different roles in a honeybee colony. This is reflected in many physiological, morphological and behavioural differences. Our overview mainly focuses on aspects of diet and metabolism in larvae and adults, and on the physiology of digestion. As larvae, drones have different protein and sugar requirements than workers, and in each life stage drones and workers differ in body composition (percentages of glycogen, lipids and proteins). Like queens, drones as adults are nourished by worker-prepared food, and compared to workers their ability to digest is reduced. Mature drones fly usually only under optimal weather conditions. Their flight metabolism and resting metabolism also differ from those of workers. We discuss these differences as adaptations to the different functions of the two sexes within the colony as a superorganism