Recent declines in honey bee populations and increasing demand for insect-pollinated crops raise concerns about pollinator shortages. Pesticide exposure and pathogens may interact to have strong negative effects on managed honey bee colonies. Such findings are of great concern given the large numbers and high levels of pesticides found in honey bee colonies. Thus it is crucial to determine how field-relevant combinations and loads of pesticides affect bee health. We collected pollen from bee hives in seven major crops to determine 1) what types of pesticides bees are exposed to when rented for pollination of various crops and 2) how field-relevant pesticide blends affect bees’ susceptibility to the gut parasite Nosema ceranae. Our samples represent pollen collected by foragers for use by the colony, and do not necessarily indicate foragers’ roles as pollinators. In blueberry, cranberry, cucumber, pumpkin and watermelon bees collected pollen almost exclusively from weeds and wildflowers during our sampling. Thus more attention must be paid to how honey bees are exposed to pesticides outside of the field in which they are placed. We detected 35 different pesticides in the sampled pollen, and found high fungicide loads. The insecticides esfenvalerate and phosmet were at a concentration higher than their median lethal dose in at least one pollen sample. While fungicides are typically seen as fairly safe for honey bees, we found an increased probability of Nosema infection in bees that consumed pollen with a higher fungicide load. Our results highlight a need for research on sub-lethal effects of fungicides and other chemicals that bees placed in an agricultural setting are exposed to.
SummaryThis study records the fifth consecutive year that winter losses of managed honey bee (Apis mellifera) colonies in the USA have been around 30%. In April 2011, a total of 5,441 US beekeepers (an estimated 11% of total US beekeepers) responded to a survey conducted by the Bee Informed Partnership. Survey respondents reported that they had lost an average of 38.4% of their colonies, for a total US colony loss of 29.9% over the winter of 2010-11. One-third of respondents (all classified as backyard beekeepers, i.e. keeping fewer than 50 colonies) reported no winter loss. There was considerable variation in both the average and total loss by state. On average, beekeepers consider acceptable losses to be 13.2%, but 68% of all responding beekeepers suffered actual losses in excess of what they considered acceptable. Of beekeepers who reported losing at least one colony, manageable conditions, such as starvation and a weak condition in the fall, were the leading self-identified causes of mortality. Respondents who indicated that varroa mites (Varroa destructor), small hive beetles (Aethina tumida), poor wintering conditions, and / or Colony Collapse Disorder (CCD) conditions were a leading cause of mortality in their operations suffered a higher average loss than beekeepers who did not list any of these as potential causes. In a separate question, beekeepers who reported the symptom "no dead bees in hive or apiary" had significantly higher losses than those who did not report this symptom. In addition, commercial beekeepers were significantly more likely to indicate that colonies died with this symptom than either backyard or sideliner beekeepers. Journal of Apicultural Research51(1): 115-124 (2012) © IBRA 2012 DOI 10.3896/IBRA.1.51.1.14 116 vanEngelsdorp et al. Una encuesta nacional sobre las pérdidas invernales de colonias manejadas de abejas melíferas 2010-11 en losEstados Unidos: resultados de la Bee Informed Partnership ResumenEste estudio registra por quinto año consecutivo que las pérdidas invernales de abejas manejadas (Apis mellifera) en Estados Unidos están en torno al 30%. En abril del 2011, un total de 5,441 apicultores de los EE.UU. (se estima que el 11% del total de apicultores de EE.UU.) respondieron a una encuesta realizada por la Bee Informed Partnership. Los encuestados indicaron que habían perdido un promedio de 38.4% de sus colonias, con una pérdida total de colonias en EE.UU. del 29.9% durante el invierno de 2010-11. Un tercio de los encuestados (todos ellos clasificados como apicultores aficionados, es decir, con menos de 50 colonias) indicaron que no tuvieron pérdidas de invierno.Hubo una variación considerable tanto en la media como en el total de pérdidas por Estado. Por término medio, los apicultores consideran aceptables pérdidas del 13.2%, sin embargo, el 68% de todos los apicultores encuestados sufrieron pérdidas reales superiores a lo que consideran aceptable. Entre los apicultores que informaron de la pérdida de al menos una colonia, las principales causas de mortalidad identificad...
El conocimiento de la anatomía y las funciones de las estructuras internas y externas es fundamental para muchos estudios sobre la abeja de la miel Apis mellifera. Del mismo modo, el dominio de técnicas de disección es vital para muchos procedimientos más complejos. En este trabajo, que es un preludio de los demás documentos del BEEBOOK COLOSS, describimos la anatomía básica de abejas y las técnicas básicas de disección.
Honey bee (Apis mellifera) colonies continue to experience high annual losses that remain poorly explained. Numerous interacting factors have been linked to colony declines. Understanding the pathways linking pathophysiology with symptoms is an important step in understanding the mechanisms of disease. In this study we examined the specific pathologies associated with honey bees collected from colonies suffering from Colony Collapse Disorder (CCD) and compared these with bees collected from apparently healthy colonies. We identified a set of pathological physical characteristics that occurred at different rates in CCD diagnosed colonies prior to their collapse: rectum distension, Malpighian tubule iridescence, fecal matter consistency, rectal enteroliths (hard concretions), and venom sac color. The multiple differences in rectum symptomology in bees from CCD apiaries and colonies suggest effected bees had trouble regulating water. To ensure that pathologies we found associated with CCD were indeed pathologies and not due to normal changes in physical appearances that occur as an adult bee ages (CCD colonies are assumed to be composed mostly of young bees), we documented the changes in bees of different ages taken from healthy colonies. We found that young bees had much greater incidences of white nodules than older cohorts. Prevalent in newly-emerged bees, these white nodules or cellular encapsulations indicate an active immune response. Comparing the two sets of characteristics, we determined a subset of pathologies that reliably predict CCD status rather than bee age (fecal matter consistency, rectal distension size, rectal enteroliths and Malpighian tubule iridescence) and that may serve as biomarkers for colony health. In addition, these pathologies suggest that CCD bees are experiencing disrupted excretory physiology. Our identification of these symptoms is an important first step in understanding the physiological pathways that underlie CCD and factors impacting bee health.
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