Soybean tissue and arthropods emtek 8114 were collected in Bt soybean fields in China at different times during the growing season to investigate the exposure of arthropods to the plant-produced Cry1Ac toxin and the transmission of the toxin within the food web.Samples from 52 arthropod species/taxa belonging to 42 families in 10 orders were analysed for their Cry1Ac content using enzyme-linked immunosorbent assay (ELISA).Among the 22 species/taxa for which three samples were analysed, toxin concentration was highest in the grasshopper Atractomorpha sinensis and represented about 50% of the concentration in soybean leaves.
Other species/taxa did not contain detectable toxin or contained a concentration that was between 1 and 10% of that detected in leaves.These Cry1Ac-positive arthropods included a number of mesophyll-feeding Hemiptera, a cicadellid, a curculionid beetle and, among the predators, a thomisid brooklyn bridge side view spider and an unidentified predatory bug belonging to the Anthocoridae.Within an arthropod species/taxon, the Cry1Ac content sometimes varied between life stages (nymphs/larvae vs.
adults) and sampling dates (before, during, and after flowering).Our study is the first to provide information on Cry1Ac-expression levels in soybean plants and Cry1Ac concentrations in non-target arthropods in Chinese soybean fields.The data will be useful for assessing the risk of non-target arthropod exposure to Cry1Ac in soybean.