Environmental assessment ofMON 810maize in the pannonian biogeographical region

Abstract

Fundamental differences between Cry1Ab-based Bt-bioinsecticides and MON 810 maize varieties render these technologies not equivalent. While the former contain at least five different crystalline (Cry) toxins, the latter produce a single Cry1Ab toxin as active ingredient. Moreover, the lectin type toxin protein produced by these plants is a truncated version of microbial Cry1Ab. The majority of the results reported for Cry1Ab content is, therefore, subject to correction between microbial Cry1Ab protoxin and plant-expressed preactivated Cry1Ab toxin, and the latter is not a registered insecticide active ingredient. Cry1Ab toxin is produced continuously and not at the highest concentration in those plant parts, where the pest occurs. In turn, MON 810 maize does not comply with IPM principles, as control cannot be limited to the period of pest damage above threshold level. The target insect, Ostrinia nubilalis is a practically inconsiderable pest in Hungary, therefore, the use of MON 810 maize is mainly groundless. Pollen settling on Urtica dioica, Rubus spp. or Datura stramonium near or in maize fields may exert toxicity on caterpillars of protected butterflies, e.g. the peacock butterfly (Nymphalis io). Decaying Bt-maize material potentially affect other non-target organisms. Occurrence of Cry1 toxin resistance in pests is facilitated by the fact that MON 810 maize produces only a single Cry protein, preactivated Cry1Ab toxin.