Mechanistic modeling of pesticide exposure: The missing keystone of honey bee toxicology Douglas B. Sponsler and Reed M. Johnson DOI: 10.1002/etc.3661 The environmental impact of chemicals in general and of pesticides in particular, is a topic of intense debate. Although it is broadly acknowledged that some pesticides pose a risk to ecosystems, there is controversy on the exact impacts of pesticide exposure. This controversy has recently centered on neonicotinoid insecticides and their possible role in insect decline in general and in honey bee losses in particular. Partly, the controversy is fueled by the fact that while laboratory experiments have clearly established the potential of adverse effects on individual bees, field studies fail to detect colony-level effects. The critical review of Sponsler and Johnson (2017) highlights a critical gap in the field of honey bee toxicology because there exists little mechanistic understanding of the patterns and processes of exposure that link honey bees to pesticides in the environment. A key finding is that honey bee exposure is distributional and not discrete, because only a subset of foraging bees may acquire harmful doses of pesticides with subsequent in-hive distribution of pesticides being driven by food transfer interactions between colony members. Clear guidance to future development of rigorous mechanistic models of honey bee pesticide exposure is provided that is to be combined with mechanistic effects modeling to integrate the field of honey bee toxicology and advance both risk assessment and basic research. Clearly, this is urgently needed—if only within the light of the current discussions on the role of pesticides in insect decline. This critical review by no doubt offers a major contribution to the future protection of insecticide health. Figure 1 Best Paper Award winner Douglas B. Sponsler. Sponsler DB, Johnson RM. 2017. Mechanistic modeling of pesticide exposure: The missing keystone of honey bee toxicology. Environ Toxicol Chem 36:871–881. Willie J.G.M Peijnenburg Dutch National Institute of Public Health and the Environment Bilthoven, The Netherlands Toxicity reference values for methylmercury effects on avian reproduction: Critical review and analysis P.C. Fuchsman, L.E. Brown, M.H. Henning, M.J. Bock, and V.S. Magar DOI:10.1002/etc.3606 Investigating the role of dissolved and droplet oil on aquatic toxicity using dispersed and passive dosing systems A.D. Redman, J.D. Butler, D.J. Letinski, and T.F. Parkerton DOI:10.1002/etc.3624 DOI: 10.1002/etc.4157 Published online in Wiley Online Library (wileyonlinelibrary.com) Passive dosing of triclosan in multi-generation tests with copepods – Stable exposure concentrations and effects at the low μg L-1 range A. Ribbenstedt, L. Mustajärvi, M. Breitholtz, E. Gorokhova, P. Mayer, and A. Sobek DOI:10.1002/etc.3649 Ingestion of Bt rice pollen does not reduce the survival or hypopharyngeal gland development of Apis mellifera adults Y. Wang, P. Dai, X. Chen, J. Romeis, J. Shi, Y. Peng, and Y. Li DOI:10.1002/etc.3647 Not all that glitters is gold—Electron microscopy study on uptake of gold nanoparticles in Daphnia magna and related artefacts L.H.S. Jensen, L.M. Skjolding, A. Thit, S.N. Sørensen, C. Købler, K. Mølhave, and A. Baun DOI:10.1002/etc.3697 Method to account for the effect of hydrodynamics on polar organic compound uptake by passive samplers K. Booij, N.L. Maarsen, M. 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