依据(代)生物体对化学品的反应预测对生态系统服务功能的影响

保护生态系统服务功能越来越多地被作为风险评估的目标，但是目前生态风险评估的终点和评估生态系统服务功能受到的潜在影响之间有很大的差距。作者提出了一个框架，将常用的生态毒理学终点与对种群和群落的影响以及生态系统的服务功能联系起来。这个框架建立在机制效应模型的长足进步上，这些模型旨在跨越多种生物组织，并解释各种生物相互作用和反馈。为了说明这一点，作者引入了2个研究案例，它们采用了已完善和已验证的机制效应模型：鱼种群的inSTREAM个体模型和AQUATOX生态系统模型。他们还展示了动态能量平衡理论可以为解释组织级毒性提供一种通用货币。他们认为，一个基于机制模型的框架，可以预测化学品暴露对生态系统服务的影响，再结合经济估值，可以为环境管理提供一种有用的方法。作者强调了使用这个框架的潜在好处以及未来工作中需要解决的挑战。
精选自Forbes, V. E., Salice, C. J., Birnir, B., Bruins, R. J.F., Calow, P., Ducrot, V., Galic, N., Garber, K., Harvey, B. C., Jager, H., Kanarek, A., Pastorok, R., Railsback, S. F., Rebarber, R. and Thorbek, P. (2017), A framework for predicting impacts on ecosystem services from (sub)organismal responses to chemicals. Environmental Toxicology and Chemistry, 36: 845–859. doi: 10.1002/etc.3720
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3720/full
     

保护生态系统亟需对农药进行注册后监测

现行的农药准入政策遵循一种可控的实验性分级风险评估方法，结果很难外推到实际情况。对DDT和烟碱类杀虫剂等化合物的分析清楚地表明，化学品对生态系统的实际影响比风险评估的预计更大。因此，为了管理由人工合成的化合物对生态系统造成的实际风险，提出了目前的化学药品准入政策，并通过注册后监测来补充。这种监测对于识别化合物通过多种传播途径和暴露方式对生物体产生的直接和间接影响是至关重要的。实施注册后监测可以建立在现有的监测网络上。这一方法将解决基于区域型法规与基于暴露型法规的现行政策僵局，更重要的是，将为跨部门间的风险评估提供一个安全锁，更有可能确保我们的自然环境得到保护。
精选自Vijver, M. G., Hunting, E. R., Nederstigt, T. A.P., Tamis, W. L.M., van den Brink, P. J. and van Bodegom, P. M. (2017), Postregistration monitoring of pesticides is urgently required to protect ecosystems. Environmental Toxicology and Chemistry, 36: 860–865. doi: 10.1002/etc.3721
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3721/full
     

蛋白组学分析揭示出阿特拉津对非洲爪蟾的生殖毒性源于其诱导生殖细胞凋亡并干扰紧密连接蛋白和代谢相关信号通路

阿特拉津可对雄性脊椎动物生殖系统造成不良影响,但其中分子机制尚不明了。本文作者将非洲爪蟾(Xenopus laevis)暴露于100 ppb的阿特拉津120 d,利用同位素标记相对和绝对定量(iTRAQ)技术检测了非洲爪蟾睾丸和卵巢中蛋白图谱的变化,结果显示100 ppb阿特拉津可影响爪蟾发育,延迟和阻碍雄性细精管的形成。组学分析显示,睾丸中143种以及卵巢中121种蛋白均表达异常,这些蛋白与细胞凋亡、细胞间紧密连接以及代谢途径相关。
精选自Xiuping Chen, Jiamei Wang, Haojun Zhu, Jiatong Ding and Yufa Peng. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine. Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2980
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2980/full     

蛋白组学分析揭示出阿特拉津对非洲爪蟾的生殖毒性源于其诱导生殖细胞凋亡并干扰紧密连接蛋白和代谢相关信号通路

阿特拉津可对雄性脊椎动物生殖系统造成不良影响，但其中分子机制尚不明了。本文作者将非洲爪蟾(Xenopus laevis)暴露于100 ppb的阿特拉津120 d，利用同位素标记相对和绝对定量(iTRAQ)技术检测了非洲爪蟾睾丸和卵巢中蛋白图谱的变化，结果显示100 ppb阿特拉津可影响爪蟾发育，延迟和阻碍雄性细精管的形成。组学分析显示，睾丸中143种以及卵巢中121种蛋白均表达异常，这些蛋白与细胞凋亡、细胞间紧密连接以及代谢途径相关。
精选自Xiuping Chen, Jiamei Wang, Haojun Zhu, Jiatong Ding and Yufa Peng. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine. Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2980
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2980/full     

蛋白组学分析揭示出阿特拉津对非洲爪蟾的生殖毒性源于其诱导生殖细胞凋亡并干扰紧密连接蛋白和代谢相关信号通路

阿特拉津可对雄性脊椎动物生殖系统造成不良影响,但其中分子机制尚不明了。本文作者将非洲爪蟾(Xenopus laevis)暴露于100 ppb的阿特拉津120 d,利用同位素标记相对和绝对定量(iTRAQ)技术检测了非洲爪蟾睾丸和卵巢中蛋白图谱的变化,结果显示100 ppb阿特拉津可影响爪蟾发育,延迟和阻碍雄性细精管的形成。组学分析显示,睾丸中143种以及卵巢中121种蛋白均表达异常,这些蛋白与细胞凋亡、细胞间紧密连接以及代谢途径相关。
精选自Xiuping Chen, Jiamei Wang, Haojun Zhu, Jiatong Ding and Yufa Peng. Proteomics analysis of Xenopus laevis gonad tissue following chronic exposure to atrazine. Environmental Toxicology and Chemistry: Volume 34, Issue 8, pages 1744–1750, August 2015. DOI: 10.1002/etc.2980
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2980/full     

没有找到微塑料对黑头软口鲦(Pimephales promelas)幼鱼摄食量和生长影响的证据

微塑料是水环境中一种含量丰富的污染物。但关于其对幼鱼的影响情况知之甚少。我们考察了塑料微珠的密度增大对黑头软口鲦(Pimephales promelas)幼鱼觅食和生长的影响。我们发现微塑料对幼鱼摄食幼虫卤虫无节幼体(Artemia nauplii)的摄食量影响很小，对30天体长也基本无影响。 精选自Timothy David Malinich, Nathan Chou, Maria S. Sepúlveda, Tomas O. H??k. No evidence of microplastic impacts on consumption or growth of larval Pimephales promelas. Environmental Toxicology and Chemistry,2018,37:2912-2918.
详情请见 https://doi.org/10.1002/etc.4257
     

以REACH为数据源进行生命周期影响评估

由于潜在生态毒理数据的限制，生态周期影响评估中的毒性模型仅仅描述了市场上的一小部分物质。改进现有的LCIA数据情况可以通过发现新的数据来源，比如欧盟化学品注册、评估、授权和限制(REACH)数据库。本研究通过对比记录在REACH数据库和UNEP/SETAC的科学统一模型USEtox中相同化学物质的生态毒理数据来探究REACH是否具有作为数据来源的潜力。数据根据数据点的个数，报道可靠性和测试时间评估，并将每种化学物质的50%涵盖物种的危险浓度与USEtox中的数据做对比。结果强调了REACH和USEtox之间不同的数据可用性。REACH和USEtox的生态毒理学数据对比表明REACH是一个LCIA毒性鉴别的潜在生态毒理学数据来源，也显示出REACH标准的数据存在着一致性的问题，以及REACH中监管风险评估的假设可能与LCIA所需数据有出入。因此，在考虑REACH标准下的数据在LCIA的运用之前，数据质量，预处理和可运用性需要进一步的研究。探究其他可用的数据来源，发表的研究与报告也需要更深入的调查。
精选自Nienke Müller, Dick de Zwart, Michael Hauschild, Ga?l Kijko, Peter Fantke. Exploring REACH as potential data source for characterizing ecotoxicity in life cycle assessment. Environmental Toxicology and Chemistry: Volume 36, Issue 2, pages 492–500, July 2017. DOI: 10.1002/etc.3542
详情请见http://onlinelibrary.wiley.com/wol1/doi/10.1002/etc.3542/full
     

腐殖酸可降低纳米银的水生生物毒性

本文作者主要研究了腐殖酸对聚乙烯吡咯烷酮包覆的纳米银颗粒(polyvinylpyrrolidone-coated AgNPs)毒性的影响，受试生物涵盖了水生系统不同的营养级别，包括藻类(Raphidocelis subcapitata)、水蚤类(Chydorus sphaericus)以及淡水鱼类(Danio rerio)。结果显示，腐殖酸可降低AgNPs对本研究中所有水生生物的毒性，并具有明显的剂量效应关系。原因为：1）腐殖酸使AgNPs表面带有更多负电荷，这阻碍了AgNPs与藻细胞的接触，使毒性降低；2）腐殖酸抑制了AgNPs中Ag⁺的溶出，而本研究显示自由Ag⁺的毒性高于团聚的纳米银颗粒。
精选自Zhuang Wang, Joris T.K. Quik, Lan Song, Evert-Jan Van Den Brandhof, Marja Wouterse and Willie J.G.M. Peijnenburg. Humic substances alleviate the aquatic toxicity of polyvinylpyrrolidone-coated silver nanoparticles to organisms of different trophic levels. Environmental Toxicology and Chemistry: Volume 34, Issue 6, pages 1239–1245, June 2015. DOI: 10.1002/etc.2936
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2936/full
     

毒代动力学一毒效动力学(Toxicokinetic-Toxicodynamic, Tk-Td)和种群模型联用评价浓度随时间变化的农药的水生态风险

利用种群模型评价农药暴露时间序列的方法与现有常用的风险评价方法进行了比较。美国环境保护局农药项目办公室(The US Environmental Protection Agency’s Office of Pesticide Programs)在近30年对水生生物农药日暴露值建立了模型，但并未对这些信息进行充分的利用。我们利用糠虾(Americamysis bahia)毒性数据和种群数量统计数据推演了毒代动力学一毒效动力学(Toxicokinetic-Toxicodynamic, Tk-Td)与一系列矩阵种群模型联用的数值。糠虾是一种沿岸浅海底的小型甲壳动物，通常用于常规毒性测试中。我们展示了这种联用方法如何仅用现有的标准常规毒性数据来优化已有的风险评价方法。我们创建了几种暴露场景，每种场景在基于生物的传统方法中有着相同的初始风险表征特征，而种群模型方法中则显示出不同的风险水平。这种TK-TD与种群模型联用的方法可以对不同的急性和慢性毒性数据的场景区分出不同的风险水平，而传统的风险评价方法则做不到。这种联用方法在风险评价方面独具优势，特别是针对污染物的暴露浓度随时间变化的情况。 精选自Glen Thursby, Keith Sappington, Matthew Etterson. Coupling Toxicokinetic-Toxicodynamic (Tk-Td) and Population Models for Assessing Aquatic Ecological Risks to Time-Varying Pesticide Exposures. Environmental Toxicology and Chemistry,2018,37:2633-2644.
详情请见 https://doi.org/10.1002/etc.4224
     

基于QSAR模型的蒙特卡洛方法分析有机化学物质对大型蚤(Daphnia magna)的毒性

本文建立一系列758种有机化合物对大型蚤(Daphnia magna)毒性的定量结构-活性关系(QSARs)。用简化的分子线性输入系统(SMILES)代表分子结构。用CORAL(关联和逻辑)软件作为工具来开发QSAR模型。这些模型使用蒙特卡罗方法建立,依据的原理是QSAR是一个“随机事件”,假设检验一组随机数据分布在可见的训练集和不可见的验证集。检验了三组分布于可见的训练、校准、测试集中的数据以及不可见的验证集。最佳模型的预测潜能,也就是其不可见的验证集的统计特征如下:n = 87,r² = 0.8377,RMSE = 0.564。建议和讨论了所构建模型的机械解释和适用领域。
精选自Alla P. Toropova, Andrey A. Toropov, Aleksandar M. Veselinovi?, Jovana B. Veselinovi?, Danuta Leszczynska, Jerzy Leszczynski. Monte Carlo based QSAR models for toxicity of organic chemicals to Daphnia magna. Environmental Toxicology and Chemistry: Volume 35, Issue 11, pages 2691–2697, November 2016. DOI: 10.1002/etc.3466
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.3466/full
     

Timekeeping in the honey bee colony: integration of circadian rhythms and division of labor

The daily patterns of task performance in honey bee colonies during behavioral development were studied to determine the role of circadian rhythmicity in age-related division of labor. Although it is well known that foragers exhibit robust circadian patterns of activity in both field and laboratory settings, we report that many in-hive tasks are not allocated according to a daily rhythm but rather are performed 24 h per day. Around-the-clock activity at the colony level is accomplished through the performance of some tasks by individual workers randomly with respect to time of day. Bees are initially arrhythmic with respect to task performance but develop diel rhythmicity, by increasing the occurrence of inactivity at night, prior to becoming foragers. There are genotypic differences for age at onset of rhythmicity and our results suggest that these differences are correlated with genotypic variation in rate of behavioral development: genotypes of bees that progressed through the age polyethism schedule faster also acquired behavioral rhythmicity at an earlier age. The ontogeny of circadian rhythmicity in honey bee workers ensures that essential in-hive behaviors are performed around the clock but also allows the circadian clock to be engaged before the onset of foraging. Received: 6 October 1997 / Accepted after revision: 28 March 1998     

Regulation of honey bee division of labor by colony age demography

The age at which worker honey bees begin foraging varies under different colony conditions. Previous studies have shown that juvenile hormone (JH) mediates this behavioral plasticity, and that worker-worker interactions influence both JH titers and age at first foraging. These results also indicated that the age at first foraging is delayed in the presence of foragers, suggesting that colony age demography directly influences temporal division of labor. We tested this hypothesis by determining whether behavioral or physiological development can be accelerated, delayed, or reversed by altering colony age structure. In three out of three trials, earlier onset of foraging was induced in colonies depleted of foragers compared to colonies depleted of an equal number of bees across all age classes. In two out of three trials, delayed onset of foraging was induced in colonies in which foragers were confined compared to colonies with free-flying foragers. Finally, in three out of three trials, both endocrine and exocrine changes associated with reversion from foraging to brood care were induced in colonies composed of all old bees and devoid of brood; JH titers decreased and hypopharyngeal glands regenerated. These results demonstrate that plasticity in age-related division of labor in honey bee colonies is at least partially controlled by social factors. The implications of these results are discussed for the recently developed ‘‘activator-inhibitor” model for honey bee behavioral development. Received: 8 November 1995/Accepted after revision: 10 May 1996     

The regulation of pollen foraging by honey bees: how foragers assess the colony's need for pollen

Summary The honey bee colony presents a challenging paradox. Like an organism, it functions as a coherent unit, carefully regulating its internal milieu. But the colony consists of thousands of loosely assembled individuals each functioning rather autonomously. How, then, does the colony acquire the necessary information to organize its work force? And how do individuals acquire information about specific colony needs, and thus know what tasks need be performed? I address these questions through experiments that analyze how honey bees acquire information about the colony's need for pollen and how they regulate its collection. The results demonstrate features of the colony's system for regulating pollen foraging: (1) Pollen foragers quickly acquire new information about the colony's need for pollen. (2) When colony pollen stores are supplemented, many pollen foragers respond by switching to nectar foraging or by remaining in the hive and ceasing to forage at all. (3) Pollen foragers do not need direct contact with pollen to sense the colony's change of state, nor do they use the odor of pollen as a cue to assess the colony's need for pollen. (4) Pollen foragers appear to obtain their information about colony pollen need indirectly from other bees in the hive. (5) The information takes the form of an inhibitory cue. The proposed mechanism for the regulation of pollen foraging involves a hierarchical system of information acquisition and a negative feedback loop. By taking advantage of the vast processing capacity of large numbers of individuals working in parallel, such a system of information acquisition and dissemination may be ideally suited to promote efficient regulation of labor within the colony. Although each individual relies on only limited, local information, the colony as a whole achieves a finely-tuned response to the changing conditions it experiences.     

Division of labor during honey bee colony defense

Summary Some worker honey bees respond to major disturbances of the colony by flying around the assailant and possibly stinging; they are a subset of the bees involved in colony defense. These defenders have an open-ended age distribution similar to that of foragers, but defensive behavior is initiated at a younger age than foraging is. Behavioral and genetic evidence shows that defenders and foragers are distinct groups of older workers. Behaviorally, defenders have less worn wings than foragers, suggesting less flight activity. Genetically, defenders differ in allozyme frequencies, demonstrating different subfamily composition from foragers in the same colony. They also differ in allozyme frequencies from guards in the same colony, providing further evidence for division of labor associated with colony defense. We use this information to develop a model for honey bee colony defense involving at least two distinct groups of workers and we propose that the non-guard defenders be called soldiers, due to their important role in colony defense.Offprint requests to: M.D. Breed     

Effects of colony food shortage on behavioral development in honey bees

Three experiments were conducted to explore the effects of severe food shortage on the control of two important and interrelated aspects of temporal division of labor in colonies of the honey bee (Apis mellifera): the size and age distribution of a colony's foraging force. The experiments were conducted with single-cohort colonies, composed entirely of young bees, allowing us to quickly distinguish the development of new (precocious) foragers from increases in activity of bees already competent to forage. In experiment 1, colony food shortage caused an acceleration of behavioral development; a significantly greater proportion of bees from starved colonies than from fed colonies became precocious foragers, and at significantly younger ages. Temporal aspects of this starvation effect were further explored in experiment 2 by feeding colonies that we initially starved, and starving colonies that we initially fed. There was a significant decrease in the number of new foragers in starved colonies that were fed, detected 1 day after feeding. There also was a significant increase in the number of new foragers in fed colonies that were starved, but only after a 2-day lag. These results suggest that colony nutritional status does affect long-term behavioral development, rather than only modulate the activity of bees already competent to forage. In experiment 3, we uncoupled the nutritional status of a colony from that of the individual colony members. The behavior of fed individuals in starved colonies was indistinguishable from that of bees in fed colonies, but significantly different from that of bees in starved colonies, in terms of both the number and age distribution of foragers. These results demonstrate that effects of starvation on temporal polyethism are not mediated by the most obvious possible worker-nest interaction: a direct interaction with colony food stores. This is consistent with previous findings suggesting the importance of worker-worker interactions in the regulation of temporal polyethism in honey bees as well as other social insects. Received: 17 April 1997 / Accepted after revision: 26 December 1997     

Honey bee foragers as sensory units of their colonies

Forager honey bees function not only as gatherers of food for their colonies, but also as sensory units shaped by natural selection to gather information regarding the location and profitability of forage sites. They transmit this information to colony members by means of waggle dances. To investigate the way bees transduce the stimulus of nectar-source profitability into the response of number of waggle runs, I performed experiments in which bees were stimulated with a sucrose solution feeder of known profitability and their dance responses were videorecorded. The results suggest that several attributes of this transduction process are adaptations to enhance a bee's effectiveness in reporting on a forage site. (1) Bees register the profitability of a nectar source not by sensing the energy gain per foraging trip or the rate of energy gain per trip, but evidently by sensing the energetic efficiency of their foraging. Perhaps this criterion of nectar-source profitability has been favored by natural selection because the foraging gains of honey bees are typically limited by energy expenditure rather than time availability. (2) There is a linear relationship between the stimulus of energetic efficiency of foraging and the response of number of waggle runs per dance. Such a simple stimulus-response function appears adequate because the range of suprathreshold stimuli (max/min ratio of about 10) is far smaller than the range of responses (max/min ratio of about 100). Although all bees show a linear stimulus-response function, there are large differences among individuals in both the response threshold and the slope of the stimulus-response function. This variation gives the colony a broader dynamic range in responding to food sources than if all bees had identical thresholds of dance response. (3) There is little or no adaptation in the dance response to a strong stimulus (tonic response). Thus each dancing bee reports on the current level of profitability of her forage site rather than the changes in its profitability. This seems appropriate since presumably it is the current profitability of a forage site, not the change in its profitability, which determines a site's attractiveness to other bees. (4) The level of forage-site quality that is the threshold for dancing is tuned by the bees in relation to forage availability. Bees operate with a lower dance threshold when forage is sparse than when it is abundant. Thus a colony utilizes input about a wide range of forage sites when food is scarce, but filters out input about low-reward sites when food is plentiful. (5) A dancing bee does not present her information in one spot within the hive but instead distributes it over much of the dance floor. Consequently, the dances for different forage sites are mixed together on the dance floor. This helps each bee following the dances to take a random sample of the dance information, which is appropriate for the foraging strategy of a honey bee colony since it is evidently designed to allocate foragers among forage sites in proportion to their profitability.     

Directional change in a suite of foraging behaviors in tropical and temperate evolved honey bees (<Emphasis Type="Italic">Apis mellifera</Emphasis> L.)

The concept of a suite of foraging behaviors was introduced as a set of traits showing associative directional change as a characterization of adaptive evolution. I report how naturally selected differential sucrose response thresholds directionally affected a suite of honey bee foraging behaviors. Africanized and European honey bees were tested for their proboscis extension response thresholds to ascending sucrose concentrations, reared in common European colonies and, captured returning from their earliest observed foraging flight. Race constrained sucrose response threshold such that Africanized bees had significantly lower sucrose response thresholds. A Cox proportional hazards regression model of honey bee race and sucrose response threshold indicated that Africanized bees were 29% (P<0.01) more at risk to forage over the 30-day experimental period. Sucrose response threshold organized age of first foraging such that each unit decrease in sucrose response threshold increased risk to forage by 14.3% (P<0.0001). Africanized bees were more likely to return as pollen and water foragers than European foragers. Africanized foragers returned with nectar that was significantly less concentrated than European foragers. A comparative analysis of artificial and naturally selected populations with differential sucrose response thresholds and the common suite of directional change in foraging behaviors is discussed. A suite of foraging behaviors changed with a change in sucrose response threshold that appeared as a product of functional ecological adaptation.Communicated by R.F.A. Moritz     

Effects of protein-constrained brood food on honey bee (<Emphasis Type="Italic">Apis mellifera</Emphasis> L.) pollen foraging and colony growth

Pollen is the sole source of protein for honey bees, most importantly used to rear young. Honey bees are adept at regulating pollen stores in the colonies based on the needs of the colony. Mechanisms for regulation of pollen foraging in honey bee are complex and remain controversial. In this study, we used a novel approach to test the two competing hypothesis of pollen foraging regulation. We manipulated nurse bee biosynthesis of brood food using a protease inhibitor that interferes with midgut protein digestion, significantly decreasing the amount of protein extractable from hypopharyngeal glands. Experimental colonies were given equal amounts of protease inhibitor-treated and untreated pollen. Colonies receiving protease inhibitor treatment had significantly lower hypopharyngeal gland protein content than controls. There was no significant difference in the ratio of pollen to nonpollen foragers between the treatments. Pollen load weights were also not significantly different between treatments. Our results supported the pollen foraging effort predictions generated from the direct independent effects of pollen on the regulation of pollen foraging and did not support the prediction that nurse bees regulate pollen foraging through amount of hypopharyngeal gland protein biosynthesis.     

Collective decision-making in honey bees: how colonies choose among nectar sources

Summary A honey bee colony can skillfully choose among nectar sources. It will selectively exploit the most profitable source in an array and will rapidly shift its foraging efforts following changes in the array. How does this colony-level ability emerge from the behavior of individual bees? The answer lies in understanding how bees modulate their colony's rates of recruitment and abandonment for nectar sources in accordance with the profitability of each source. A forager modulates its behavior in relation to nectar source profitability: as profitability increases, the tempo of foraging increases, the intensity of dancing increases, and the probability of abandoning the source decreases. How does a forager assess the profitability of its nectar source? Bees accomplish this without making comparisons among nectar sources. Neither do the foragers compare different nectar sources to determine the relative profitability of any one source, nor do the food storers compare different nectar loads and indicate the relative profitability of each load to the foragers. Instead, each forager knows only about its particular nectar source and independently calculates the absolute profitability of its source. Even though each of a colony's foragers operates with extremely limited information about the colony's food sources, together they will generate a coherent colonylevel response to different food sources in which better ones are heavily exploited and poorer ones are abandoned. This is shown by a computer simulation of nectar-source selection by a colony in which foragers behave as described above. Nectar-source selection by honey bee colonies is a process of natural selection among alternative nectar sources as foragers from more profitable sources survive (continue visiting their source) longer and reproduce (recruit other foragers) better than do foragers from less profitable sources. Hence this colonial decision-making is based on decentralized control. We suggest that honey bee colonies possess decentralized decision-making because it combines effectiveness with simplicity of communication and computation within a colony. Offprint requests to: T.D. Seeley     

Manuscript in preparation for <Emphasis Type="Italic">Behavioral Ecology and Sociobiology</Emphasis> Bumble bee pollen foraging regulation: role of pollen quality,storage levels,and odor

The regulation of protein collection through pollen foraging plays an important role in pollination and in the life of bee colonies that adjust their foraging to natural variation in pollen protein quality and temporal availability. Bumble bees occupy a wide range of habitats from the Nearctic to the Tropics in which they play an important role as pollinators. However, little is known about how a bumble bee colony regulates pollen collection. We manipulated protein quality and colony pollen stores in lab-reared colonies of the native North American bumble bee, Bombus impatiens. We debut evidence that bumble bee colony foraging levels and pollen storage behavior are tuned to the protein quality (range tested: 17–30% protein by dry mass) of pollen collected by foragers and to the amount of stored pollen inside the colony. Pollen foraging levels (number of bees exiting the nest) significantly increased by 55%, and the frequency with which foragers stored pollen in pots significantly increased by 233% for pollen with higher compared to lower protein quality. The number of foragers exiting the nest significantly decreased (by 28%) when we added one pollen load equivalent each 5 min to already high intranidal pollen stores. In addition, pollen odor pumped into the nest is sufficient to increase the number of exiting foragers by 27%. Foragers directly inspected pollen pots at a constant rate over 24 h, presumably to assess pollen levels. Thus, pollen stores can act as an information center regulating colony-level foraging according to pollen protein quality and colony need. An erratum to this article can be found at