Two-year field data on neonicotinoid concentrations in guttation drops of seed treated maize (Zea mays)
We present neonicotinoid concentrations in guttation drops of commonly used maize (Zea mays) cultivars, germinated from seeds coated with active substances (a.s.): i) imidacloprid (IMD), ii) clothianidin (CTN) and iii) thiamethoxam (THM) over two growing seasons. In one variant clothianidin was applied as seed granule. The trial took place at the experimental fields of the Julius Kühn-Institut in Berlin in 2010 and 2011. Data from 2010 are related to a presentation of “Pesticides in guttation droplets following seed treatment – field studies” (Schenke et al., 2011)  presented at the SETAC North America conference and only some figures were used in the “Scientific opinion on the science behind the development of a risk assessement of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees)” (EFSA, 2012) . Only parts of the data from 2011 was presented in relation to the “Exposure of Coccinellidae to guttation droplets on maize seedlings with seed or granule treatment of neonicotinoids” (Schenke and Heimbach, 2014) . The article describes the study sites, the variants of treated maize seeds, sample collection and the analytical methods used to quantify the neonicotinoids and relevant metabolites of IMD (5-OH-IMD and IMD-olefine) and of THM (CTN) in guttation drop samples. The complete field data set is publicly available at the OpenAgrar repository under https://doi.org/10.5073/20180907-142020 (Schenke et al., 2018) .