Overhaul pesticide testing on bees

Political action is needed to address the adverse side effects of systemic pesticides on bees (Nature 496, 408; 2013) by revising procedures for pesticide registration. The current risk-assessment process for these chemicals is outdated and does not incorporate important developments from the past 30 years.

To register a new pesticide in industrialized countries, the substance must be assessed for toxicity to the honeybee (Apis mellifera), which was originally chosen as a representative model of the Apoidea superfamily of some 20,000 bee species. However, the life histories of different bee species vary considerably. Unlike honeybees, most bee species are solitary, so individuals killed by pesticides are not easily replaced. There are 42 studies (source: Web of Science) reporting side effects of registered pesticides on other bee species, even though these passed risk assessment for honeybees. Tests need to be much more sensitive if they are to pick up all pesticide-related effects for bees as a whole.

Current risk assessments evaluate the survival of adult honeybees only after a short exposure to pesticide. However, numerous studies have stressed the importance of also testing for chronic toxicity, larval toxicity and sublethal effects of pesticides (N. Desneux et al. Annu. Rev. Entomol. 52, 81–106; 2007).

More rigorous pesticide testing therefore needs to include a broader range of exposure scenarios and to take relevant biological traits into account. This will stand to improve insect pollination generally, which is currently worth about €153 billion (US$202 billion) annually worldwide (N. Gallai et al. Ecol. Econ. 68, 810–821; 2009).