Social disruption: Sublethal pesticides in pollen lead to Apis mellifera queen events and brood loss

Eusocial Apis mellifera colonies depend on queen longevity and brood viability to survive, as the queen is the sole reproductive individual and the maturing brood replenishes the shorter-lived worker bees. Production of many crops rely on both pesticides and bee pollination to improve crop quantity and quality, yet sublethal impacts of this pesticide exposure is often poorly understood. We investigated the resiliency of queens and their brood after one month of sublethal exposure to field relevant doses of pesticides that mimic exposure during commercial pollination contracts. We exposed full size colonies to pollen contaminated with field-relevant doses of the fungicides (chlorothalonil and propicanizole), insecticides (chlorypyrifos and fenpropathrin) or both, noting a significant reduction in pollen consumption in colonies exposed to fungicides compared to control. While we found no difference in the total amount of pollen collected per colony, a higher proportion of pollen to nonpollen foragers was detected in all pesticide exposed colonies. After ceasing treatments, we measured brood development, discovering a significant increase in brood loss and/or cannibalism across all pesticide exposed groups. Sublethal pesticide exposure in general was linked to reduced production of replacement workers and a change in protein acquisition (pollen vs. non-pollen foraging). Fungicide exposure also resulted in increased loss of the reproductive queen

Defined exposure of honey bee colonies to simulated radiofrequency electromagnetic fields (RF-EMF): Negative effects on the homing ability, but not on brood development or longevity

Urbanization and the increasing use of wireless technologies lead to higher emission rates of radiofrequency electromagnetic fields (RF-EMF) in populated areas. This anthropogenic electromagnetic radiation is a form of environmental pollution and a potential stressor on bees or other flying insects. Cities often have a high density of wireless devices operating on microwave frequencies, which generate electromagnetic frequencies e.g. in the 2.4 and 5.8 GHz bands commonly used by the wireless technologies. To date the effects of nonionizing electromagnetic radiation on the vitality and behavior of insects are poorly understood. In our experiment we used honey bees as model organisms and analyzed the effects of defined exposures to 2.4 and 5.8 GHz on brood development, longevity and homing ability under field conditions. To generate this radiation, we used a high-quality radiation source which generates a consistent, definable and realistic electromagnetic radiation, engineered for this experiment by the Communications Engineering Lab (CEL) at the Karlsruhe Institute of Technology. Our results show significant effects of long-term exposures on the homing ability of foraging honey bees, but no effects on brood development and adult worker longevity. Using this novel and high-quality technical set-up, this interdisciplinary work provides new data on the effects of these widely used frequencies on important fitness parameters of free-flying honey bees

Social networks predict the life and death of honey bees

In complex societies, individuals' roles are reflected by interactions with other conspecifics. Honey bees (Apis mellifera) generally change tasks as they age, but developmental trajectories of individuals can vary drastically due to physiological and environmental factors. We introduce a succinct descriptor of an individual's social network that can be obtained without interfering with the colony. This 'network age' accurately predicts task allocation, survival, activity patterns, and future behavior. We analyze developmental trajectories of multiple cohorts of individuals in a natural setting and identify distinct developmental pathways and critical life changes. Our findings suggest a high stability in task allocation on an individual level. We show that our method is versatile and can extract different properties from social networks, opening up a broad range of future studies. Our approach highlights the relationship of social interactions and individual traits, and provides a scalable technique for understanding how complex social systems function. Honey bee workers take on different tasks for the colony as they age. Here, the authors develop a method to extract a descriptor of the individuals' social networks and show that interaction patterns predict task allocation and distinguish different developmental trajectories

Varroa destructor: A Complex Parasite, Crippling Honey Bees Worldwide

The parasitic mite, Varroa destructor, has shaken the beekeeping and pollination industries since its spread from its native host, the Asian honey bee (Apis cerana), to the naive European honey bee (Apis mellifera) used commercially for pollination and honey production around the globe. Varroa is the greatest threat to honey bee health. Worrying observations include increasing acaricide resistance in the varroa population and sinking economic treatment thresholds, suggesting that the mites or their vectored viruses are becoming more virulent. Highly infested weak colonies facilitate mite dispersal and disease transmission to stronger and healthier colonies. Here, we review recent developments in the biology, pathology, and management of varroa, and integrate older knowledge that is less well known

Medical Honey for Wound Care—Still the ‘Latest Resort’?

While the ancient Egyptians and Greeks used honey for wound care, and a broad spectrum of wounds are treated all over the world with natural unprocessed honeys from different sources, Medihoney™ has been one of the first medically certified honeys licensed as a medical product for professional wound care in Europe and Australia. Our experience with medical honey in wound care refers only to this product. In this review, we put our clinical experience into a broader perspective to comment on the use of medical honey in wound care. More prospective randomized studies on a wider range of types of wounds are needed to confirm the safety and efficacy of medical honey in wound care. Nonetheless, the current evidence confirming the antibacterial properties and additional beneficial effects of medical honey on wound healing should encourage other wound care professionals to use CE-certified honey dressings with standardized antibacterial activity, such as Medihoney™ products, as an alternative treatment approach in wounds of different natures

Excesses of responsibility: the limits of law and the possibilities of politics

Since 1945 responsibility for atrocity has been individualized, and international tribunals and courts have been given effective jurisdiction over it. This article argues that the move to individual responsibility leaves significant ‘excesses’ of responsibility for war crimes unaccounted for. When courts do attempt to recognize the collective nature of war crime perpetration, through the doctrines of ‘command responsibility’, ‘joint criminal enterprise’ and ‘state responsibility’, the application of these doctrines has, it is argued, limited or perverse effects. The article suggests that instead of expecting courts to allocate excesses of responsibility, other accountability mechanisms should be used alongside trials to allocate political (rather than legal) responsibility for atrocity. The mechanisms favored here are ‘Responsibility and Truth Commissions’, i.e. well-resourced non-judicial commissions which are mandated to hold to account individual and collective actors rather than simply to provide an account of past violence

Queen and young larval pheromones impact nursing and reproductive physiology of honey bee (Apis mellifera) workers.

Several insect pheromones are multifunctional and have both releaser and primer effects. In honey bees (Apis mellifera), the queen mandibular pheromone (QMP) and e-beta-ocimene (eβ), emitted by young worker larvae, have such dual effects. There is increasing evidence that these multifunctional pheromones profoundly shape honey bee colony dynamics by influencing cooperative brood care, a fundamental aspect of eusocial insect behavior. Both QMP and eβ have been shown to affect worker physiology and behavior, but it has not yet been determined if these two key pheromones have interactive effects on hypopharyngeal gland (HPG) development, actively used in caring of larvae, and ovary activation, a component of worker reproductive physiology. Experimental results demonstrate that both QMP and eβ significantly suppress ovary activation compared to controls but that the larval pheromone is more effective than QMP. The underlying reproductive anatomy (total ovarioles) of workers influenced HPG development and ovary activation, so that worker bees with more ovarioles were less responsive to suppression of ovary activation by QMP. These bees were more likely to develop their HPG and have activated ovaries in the presence of eβ, providing additional links between nursing and reproductive physiology in support of the reproductive ground plan hypothesis