The methodology presented here focuses on the exposure of bees to contaminated flowers resulting from treated plants (as seed and soil treatments, bulbs or roots bathing). Observations are done at the level of the colony and only individual observations on bees are included insofar as they may affect colony development. In principle, guttation water would not be a major source of exposure given that normally these droplets occur mainly in early plant developmental stages (Girolami et al., 2009; Tapparo et al., 2012). However, the individual geographical and meteorological conditions of each area should be considered to exclude this potential exposure route.

The EFSA has published an extensive review about the risk assessment of pesticides on bees (EFSA, 2012). In this document, a thorough analysis has been conducted concerning the adequacy of the international standards (EPPO, 2010a) recommended for field-testing to the exposure of bees to systemic pesticides. The following recommendations are based on the limitations identified on the EFSA document.