A national survey of managed honey bee 2012–2013 annual colony losses in the USA: results from the Bee Informed Partnership

Abstract

SummaryFor the past six years in which overwintering mortality of honey bee colonies has been surveyed in the USA, estimates of colony loss have fluctuated around one-third of the national population. Here we report on the losses for the 2012-2013 seasons. We collected data from 6,482 US beekeepers (6,114 backyard, 233 sideline, and 135 commercial beekeepers) to document overwintering mortality rates of honey bee colonies for the USA. Responding beekeepers reported a total 30.6% (95% CI: 30.16-31.13%) loss of US colonies over the winter, with each beekeeper losing on average 44.8% (95% CI: 43.88-45.66%) of their colonies. Total winter losses varied across states (range: 11.0% to 54.7%). The self-reported level of acceptable winter loss was 14.6%, and 73.2% of the respondents had mortality rates greater than this level. The leading self-identified causes of overwintering mortality were different according to the operation type; backyard beekeepers generally self-identified "manageable" factors (e.g., starvation, weak colony in the fall), while commercial beekeepers generally identified nonmanageable factors (e.g., queen failure, pesticides) as the main cause of losses. For the first time in this series of surveys, we estimated mortality during the summer (total loss = 25.3% (95% CI: 24.80-25.74%), average loss = 12.5% (95% CI: 11.92-13.06%)). The entire 12-months period between April 2012 and April 2013 yielded a total loss of 45.2% (95% CI: 44.58-45.75%), and an average loss of 49.4% (95% CI: 48.46-50.43%). While we found that commercial beekeepers lost fewer colonies than backyard beekeepers in the winter (30.2% (95% CI:26.54-33.93% vs 45.4% (44.46-46.32%) respectively), the situation was reversed in the summer where commercial beekeepers reported higher average losses than backyard beekeepers (21.6% (95% CI: 18.4-24.79%) vs 12.1% (11.46-12.65%)). These findings demonstrate the ongoing difficulties of US beekeepers in maintaining overall colony heath and survival.Encuesta nacional anual sobre pérdidas de colonias manejadas de la abeja de la miel 2012-2013 en EE.UU.: resultados de la Asociación Abeja Informada ResumenDurante los últimos 6 años en los que la mortalidad invernal de colonias de abejas de la miel ha sido monitoreada en los EE.UU., las estimaciones de pérdida de colonias han fluctuado en torno a un tercio de la población nacional. Aquí informamos sobre las pérdidas para las temporadas 2012-2013. Se recogieron datos de 6,482 apicultores de Estados Unidos (6,114 tradicionales, 233 como negocio complementario, 2 Steinhauer et al.

Impact of Varroa destructor on honeybee (Apis mellifera scutellata) colony development in South Africa

“…The European honeybee does not express these traits at a level at which they confer tolerance to the parasite ). This became obvious after the mite shifted host from A. cerana to A. mellifera L. (Rath and Drescher 1990;Solignac et al 2005) and became responsible for the mortality of a large number of honeybee colonies in several regions of the world where it has spread (see references in Dietemann et al 2012;van Dooremalen et al 2013;Spleen et al 2013;Steinhauer et al 2014). Apis mellifera colonies cannot survive without chemical treatment against Varroa mites and colonies usually die within one to three years if left untreated (Martin 1998;Rosenkranz et al 2010).…”

Risk indicators affecting honeybee colony survival in Europe: one year of surveillance

“…Although no reference values exist for the acceptable level of colony losses during winter, various acceptable rates of winter colony mortality were reported in European countries (Charrière and Neumann 2010;Genersch et al 2010) and outside Europe (Head et al 2010;Steinhauer et al 2014). The seasonal mortality rates of each country were compared to the mean seasonal mortality of participating countries.…”

“…Many publications that looked into colony losses from any part of the world reported that several biological and environmental factors acting alone or in combination have the potential to cause premature colony mortality (Genersch et al 2010;Potts et al 2010; Spleen et al 2013). In the USA and Canada, alarming losses of honeybee colonies were recently reported (Steinhauer et al 2014). In Europe, the decrease in honeybee colonies was estimated at Corresponding author: M. Chauzat, marie-…”

Weight of evidence evaluation of a network of adverse outcome pathways linking activation of the nicotinic acetylcholine receptor in honey bees to colony death

“…Declines in honey bee colony health and high colony losses have been reported by beekeepers over the last decade at rates, ranging from 23 to 41% (Lee et al, 2015b;Spleen et al, 2013;Steinhauer et al, 2014;Seitz et al, 2015;vanEngelsdorp et al, 2010;vanEngelsdorp et al, 2011;vanEngelsdorp et al, 2012). These levels are noticeably higher than the economically sustainable losses of about 15% reported by the US beekeepers (Steinhauer et al, 2014).…”

“…These levels are noticeably higher than the economically sustainable losses of about 15% reported by the US beekeepers (Steinhauer et al, 2014). Many stressors, including pests, pathogens, agricultural intensification, poor nutrition, improper management practices, failing queens, and pesticide exposure have been identified as contributing to continued high losses (Evans et al, 2009;Seitz et al, 2015).…”