No abstract

Running title -Weeds maximize nature benefits to crops AbstractOngoing expansion of large-scale agriculture critically threatens natural habitats and the pollination services they offer. Creating patches with high plant diversity within farmland is commonly suggested as a measure to benefit pollinators. However, farmers rarely adopt such practice, instead removing naturally occurring plants (weeds). By combining pollinator exclusion experiments with analysis of honeybee behaviour and flower-visitation webs, we found that the presence of weeds allowed pollinators to persist within sunflower fields, maximizing the benefits of the remaining patches of natural habitat to productivity of this large-scale crop. Weed diversity increased flower visitor diversity, hence ameliorating the measured negative effects of isolation from natural habitat. Although honeybees were the most abundant visitors, diversity of flower visitors enhanced honeybee movement, being the main factor influencing productivity.Conservation of natural patches combined with promoting flowering plants within crops can maximize productivity and, therefore, reduce the need for cropland expansion, contributing towards sustainable agriculture.

SummarySmall hive beetles, Aethina tumida, are parasites and scavengers of honey bee and other social bee colonies native to sub-Saharan Africa, where they are a minor pest only. In contrast, the beetles can be harmful parasites of European honey bee subspecies. Very rapidly after A. tumida established populations outside of its endemic range, the devastating effect of this beetle under suitable climatic conditions prompted an active research effort to better understand and control this invasive species. Over a decade, A. tumida has spread almost over the entire USA and across the east coast of Australia. Although comparatively few researchers have worked with this organism, a diversity of research methods emerged using sets of diverse techniques to achieve the same goal. The diversity of methods made the results difficult to compare, thus hindering our understanding of this parasite. Here, we provide easy-to-use protocols for the collection, identification, diagnosis, rearing, and for experimental essays of A. tumida. We hope that these methods will be embraced as standards by the community when designing and performing research on A. tumida. Métodos estandar para la investigación del pequeño escarabajo de las colmenas ResumenLos pequeños escarabajos de la colmena, Aethina tumida, son parásitos y carroñeros de la abeja de la miel y otras colonias de abejas sociales nativas de África subsahariana, donde sólo son una plaga menor. Sin embargo, los escarabajos pueden ser parásitos dañinos de las subespecies de abejas europeas. Muy rápidamente después de que A. tumida estableciera poblaciones fuera de su área endémica, el efecto devastador de este escarabajo en condiciones climáticas adecuadas impulsó un activo esfuerzo de investigación para comprender y controlar mejor esta especie invasora. En más de una década, A. tumida se ha extendido prácticamente por todos los EE.UU. y en toda la costa este de Australia. Aunque comparativamente son pocos los investigadores que han trabajado con este organismo, surgió una diversidad de métodos de investigación utilizando diversas técnicas para lograr el mismo objetivo. La diversidad de métodos complica la comparación de los resultados, lo que dificulta la comprensión de este parásito. Aquí, ofrecemos protocolos fáciles de utilizar para la recolección, la identificación, el diagnóstico, la crianza, y para ensayos experimentales con A. tumida. Esperamos que estos métodos se adopten como normas estándar por la comunidad para el diseño y la realización de investigaciones sobre A. tumida.

-Pollen is the natural source of protein for bees and it is commonly assumed that a high protein content in pollen is beneficial. Investigation of the optimal nutrient ratio for honeybees was prompted by our earlier study showing surprisingly high mortality in caged honeybees fed with the protein-rich pollen of Aloe greatheadii var davyana, although field bees experience optimal growth when feeding on this pollen. We tested the effect of different protein sources and different protein:carbohydrate (P:C) ratios on the survival and ovarian activation of caged bees. Bees fed casein showed consistently higher survival than those fed royal jelly or aloe pollen, regardless of P:C ratios. They survived longer on lower P:C ratios and longest on a pure carbohydrate diet. The greatest ovarian activation was recorded for bees fed royal jelly in a 1:3 P:C ratio, showing the superior quality of royal jelly for supporting development.Aloe / macronutrients / pollen / casein / royal jelly

SUMMARY The nutritional needs of bees are supplied by nectar carbohydrates and by protein and other nutrients in pollen but little is known of how bees achieve nutritional balance. Using newly emerged caged worker honeybees (Apis mellifera scutellata), we investigated whether bees maintain their intake target when confined to pairs of imbalanced complementary diets varying in protein to carbohydrate (P:C) ratio. Diets were formulated using three protein sources [casein, royal jelly or Feed-Bee® (a natural pollen substitute)] and sucrose. Within each protein type, honeybees switched between complementary diets and converged on the same P:C intake target. However, this target differed between protein types: P:C ratios were 1:12, 1:14 and 1:11 on casein, royal jelly and Feed-Bee® diets, respectively. Except for an early peak in protein consumption on royal jelly diets, these strongly convergent ratios remained constant over the 14 day experiment. This is probably due to the absence of brood, reflected in relatively stable values measured for haemolymph protein concentration and hypopharyngeal gland activation in bees on Feed-Bee® diets. Performance of caged workers was also assessed in terms of survival and ovarian activation. Survival was highest on casein diets and lowest on Feed-Bee® diets but ovarian activation was highest on royal jelly diets and lowest on casein diets. This may be due to additional components in Feed-Bee® and royal jelly (e.g. fatty acids), which are needed to activate the ovaries but also reduce survival. Nutrient intake of broodless workers is directly related to their own physiological requirements, and the strong carbohydrate bias may reflect the high metabolic rate of honeybees even under resting conditions.

SummaryA variety of methods are used in honey bee research and differ depending on the level at which the research is conducted. On an individual level, the handling of individual honey bees, including the queen, larvae and pupae are required. There are different methods for the immobilising, killing and storing as well as determining individual weight of bees. The precise timing of developmental stages is also an important aspect of sampling individuals for experiments. In order to investigate and manipulate functional processes in honey bees, e.g. memory formation and retrieval and gene expression, microinjection is often used. A method that is used by both researchers and beekeepers is the marking of queens that serves not only to help to locate her during her life, but also enables the dating of queens. Creating multiple queen colonies allows the beekeeper to maintain spare queens, increase brood production or ask questions related to reproduction. On colony level, very useful techniques are the measurement of intra hive mortality using dead bee traps, weighing of full hives, collecting pollen and nectar, and digital monitoring of brood development via location recognition. At the population level, estimation of population density is essential to evaluate the health status and using beelines help to locate wild colonies. These methods, described in this paper, are especially valuable when investigating the effects of pesticide applications, environmental pollution and diseases on colony survival. Métodos estándar diversos para la investigación en Apis mellifera ResumenEn la investigación de la abeja de la miel, se han usado una variedad de métodos que se diferencian en función del nivel en el que se realiza la investigación. Al nivel individual, el manejo de las abejas individuales es necesario, incluyendo a la reina, las larvas y las pupas. Existen diferentes métodos para la inmovilización, mortandad y almacenamiento, así como para la determinación del peso individual de las abejas. La precisión en la sincronización de las etapas de desarrollo es también un aspecto importante de los experimentos con muestreos individuales.La microinyección se utiliza a menudo con el fin de investigar y manipular los procesos funcionales de las abejas melíferas, como por ejemplo, la formación y recuperación de la memoria y la expresión génica. Un método utilizado tanto por investigadores como apicultores es el marcado de las reinas, que sirve no sólo para ayudar a localizarlas durante su vida, sino que también permite su datación. La creación de varias colmenas a partir de reinas permite al apicultor mantener reinas de repuesto, aumentar la producción de cría o hacer preguntas relacionadas con la reproducción. Al nivel de colmena, la medición de la mortalidad intra colmena utilizando trampas de abejas muertas, el pesaje de las colmenas completas, la recolección de polen y néctar, y el seguimiento digital del desarrollo de la cría a través del reconocimiento de su ubicación, son algunas de las técnicas más útiles. Al nivel p...

No abstract

Insecticides are thought to be among the major factors contributing to current declines in bee populations. However, detoxification mechanisms in healthy, unstressed honey bees are poorly characterised. Alkaloids are naturally encountered in pollen and nectar, and we used nicotine as a model compound to identify the mechanisms involved in detoxification processes in honey bees. Nicotine and neonicotinoids have similar modes of action in insects. Our metabolomic and proteomic analyses show active detoxification of nicotine in bees, associated with increased energetic investment and also antioxidant and heat shock responses. The increased energetic investment is significant in view of the interactions of pesticides with diseases such as Nosema spp which cause energetic stress and possible malnutrition. Understanding how healthy honey bees process dietary toxins under unstressed conditions will help clarify how pesticides, alone or in synergy with other stress factors, lead to declines in bee vitality.