The genomes of two key bumblebee species with primitive eusocial organization

Background: The shift from solitary to social behavior is one of the major evolutionary transitions. Primitively eusocial bumblebees are uniquely placed to illuminate the evolution of highly eusocial insect societies. Bumblebees are also invaluable natural and agricultural pollinators, and there is widespread concern over recent population declines in some species. High-quality genomic data will inform key aspects of bumblebee biology, including susceptibility to implicated population viability threats. Results: We report the high quality draft genome sequences of Bombus terrestris and Bombus impatiens, two ecologically dominant bumblebees and widely utilized study species. Comparing these new genomes to those of the highly eusocial honeybee Apis mellifera and other Hymenoptera, we identify deeply conserved similarities, as well as novelties key to the biology of these organisms. Some honeybee genome features thought to underpin advanced eusociality are also present in bumblebees, indicating an earlier evolution in the bee lineage. Xenobiotic detoxification and immune genes are similarly depauperate in bumblebees and honeybees, and multiple categories of genes linked to social organization, including development and behavior, show high conservation. Key differences identified include a bias in bumblebee chemoreception towards gustation from olfaction, and striking differences in microRNAs, potentially responsible for gene regulation underlying social and other traits. Conclusions: These two bumblebee genomes provide a foundation for post-genomic research on these key pollinators and insect societies. Overall, gene repertoires suggest that the route to advanced eusociality in bees was mediated by many small changes in many genes and processes, and not by notable expansion or depauperation

Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps

It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines

Safeguarding pollinators and their values to human well-being

Wild and managed pollinators provide a wide range of benefits to society in terms of contributions to food security, farmer and beekeeper livelihoods, social and cultural values, as well as the maintenance of wider biodiversity and ecosystem stability. Pollinators face numerous threats, including changes in land-use and management intensity, climate change, pesticides and genetically modified crops, pollinator management and pathogens, and invasive alien species. There are well-documented declines in some wild and managed pollinators in several regions of the world. However, many effective policy and management responses can be implemented to safeguard pollinators and sustain pollination services

Ecological Modeling of the North-sea

North Sea ecosystem models published in accessible literature are partitioned into groups with respect to their emphasis on significance and detail of different trophic levels of the ecosystem. These subsets are treated separately in the three main chapters, which deal with relationships with physical dynamics, lower trophic level interactions and higher trophic level interactions. They are preceded by chapters that introduce the scope of the models, the history of modelling approaches, main purposes and specific aims, general aspects of internal structure, and modelling techniques applied. The main chapters compare the process descriptions characteristic of the subsets of models, and discuss aims and results with emphasis on significance and contribution of the processes considered. The chapter on plankton dynamics in relation to physical dynamics relates plankton responses in the mixed layer to changes in the physical environment. Attention is given to seasonal forcing functions, the coupling of horizontal and vertical plankton distributions, the flow of matter and the sensitivity of the plankton system. The chapter on lower trophic levels deals with primary production and its limiting factors, nutrient cycles, eutrophication, the microbial loop, and mineralization of organic matter in the pelagic and benthic compartments. The chapter on higher trophic levels highlights predator-prey interactions, the impact of grazing, and the significance of predation for system stability. A final chapter discusses what has been achieved so far with models of North Sea ecosystems and what must be aimed at in the future. It argues for lucidity and more methodology in simplification to the degree allowed by the questions to be solved, more attention for models as carriers of unifying concepts in marine ecological theory, technical solutions in handling different time and space scales for different processes and distributions, cooperation of different disciplines to find answers to questions of general importance, and the formation of data bases for model validation

Central and peripheral nervous complications of dental treatment Complicações de tratamento dentário afetando o sistema nervoso

This review outlines the complications involving the central or peripheral nervous system arising from dental procedures reported in the last decade. By far the commonest complications were related to intraoperative mechanical peripheral nerve injury. Trauma to branches of the mandibular nerve occuring during oral operations may potentially result in varying degrees of hypoesthesia, paresthesia, dysesthesia or in chronic pain syndromes. An increase in malpractice suits related to such a complication has been recognized in the late years. A warning of the possibility of occurrence of this complication should to be given to all patients undergoing risky procedures as part of the process of obtaining informed consent to operation. Mandibular third molar extraction seems to be alone the most hazardous procedure related to mechanical nerve injuries and also with anesthesiological accidents. Severe but rather infrequent infectious (meningitis, brain abscess and cavernous sinus thrombophlebitis) and anesthesiological complications (occular and facial palsies, optic nerve injury and complications related to general anesthesia) were also reported in this period.<br>Complicações, ou eventos inesperados e indesejáveis associados a terapia de uma dada condição, podem ser particularmente incapacitantes quando afetam o sistema nervoso. A proximidade de cavidade craniana e a rica inervação dos tecidos orais representam risco potencialmente alto de disseminação de infecções para o sistema nervoso central e de lesões de troncos nervosos em procedimentos dentários. Em vista do aumento da ocorrência de processos para compensação financeira após tais complicações, é provável que parcela considerável desses pacientes venham a ser examinados por neurologistas. As complicações de tratamento dentário afetando o sistema nervoso central e periférico referidas na literatura (1982-1994) são tema desta revisão. As complicações mais comuns foram as lesões dos ramos da divisão mandibular do nervo trigêmeo provocadas por trauma mecânico. A extração do terceiro molar mandibular foi o procedimento dentário com maior morbidade tanto com relação a trauma mecânico quanto a acidente anestésico. Nesse procedimento o nervo lingual pode ser traumatizado em 11% a 15% das operações e o nervo alveolar inferior em 4,4% a 5,5%. Os sintomas são permanentes em 0,5% a 1,0%. Outras complicações potencialmente severas porém infrequentes no período estudado foram as infecções (meningite, tromboflebite do seio cavernoso e abscesso cerebral) e as complicações anestésicas (oftalmoplegia, paralisia facial e complicações da anestesia geral)