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International audience; This chapter proposes a method for estimating risk to honey bees (Apis mellifera) and non-Apis bees from pesticides that are applied through sprays (acting on contact) and through seed or soil treatments and tree trunk injections (acting systemically). It describes the risk assessment process for honey bees and non-Apis bees. Problem formulation articulates the intent of the risk assessment and is predicated on particular protection goals for which the regulatory authority is responsible. The chapter illustrates the proposed risk assessment process identified by the participants of the 2011 SETAC Workshop on Pesticide Risk Assessment for Pollinators. The potential risk to adult honey bees from spray applications is assessed through calculation of an HQ. The screening-level and refined risk assessment processes for soil or seed treatment-applied pesticides incorporate different degrees of ecological realism. Screening-level assessments are typically based on conservative assumptions regarding both exposure and effects.

An essential component of an ecological risk assessment is a prediction of exposure of the organisms being assessed. This chapter outlines exposure pathways for the different pesticide delivery methods, both nonsystemic and systemic, and discusses methods used to predict pesticide exposure to honey bees and non-Apis bees. It provides an outline of techniques employed to measure pesticide residues in relevant matrices and discusses higher tier field study designs that are used to refine bee exposure assessments for specific products. The chapter presents perspectives regarding pesticide application technologies that can be employed to mitigate bee exposure, as well as future research needs to further refine exposure assessments for this taxa. Workshop participants agreed that the most significant route of exposure to bees from foliar-applied pesticides is from both contact and oral exposure to contaminated pollen, nectar, and processed food.

To evaluate the effect of the indoxacarb 300 g kg -1 WG, Steward 30WDG™, on the honey bee (Apis mellifera L.) in apple orchards, a monitoring study was conducted in Dutch apple orchards in April/May 2004. Before apple flowering began, two honey bee colonies were placed in each orchard to investigate honey bee mortality. Each hive was provided with a Minister dead bee trap to collect dead honey bees. The numbers of dead bees found in these Minister dead traps were counted every 3-4 days for about 2 weeks before and after the period of the insecticide treatment. In nine flowering orchards no indoxacarb was applied during the flowering period, which served as control sites. In 30 flowering orchards indoxacarb was sprayed by the fruit growers according to local practice at 170-260 g formulated product ha -1 (51-78 g AI ha -1 ). In the control orchards the average mortality was 8 honey bees colony -1 day -1 . The average daily honey bee mortality before and after indoxacarb application was 8 and 10 honey bees colony -1 day -1 respectively. At one test site, indoxacarb was mixed with other plant protection products plus plant nutrients, and in this orchard a slight but biologically non-significant increase in acute honey bee mortality was recorded. It was concluded that the application of indoxacarb caused no effects on honey bee mortality, and that the number of dead honey bees counted in the Munster traps in the orchard treated with indoxacarb was comparable with those determined in control orchards.