D3346: An environmental risk assessment of IPD079Ea: A protein derived from Ophioglossum pendulum with activity against Diabrotica spp. in corn

Farmers face significant pressure from insects in their corn fields, particularly from corn rootworm (Diabrotica spp.). An active area of research into proteins capable of potentially demonstrating insecticidal activity has found several possibilities produced by various species of ferns. One such protein, IPD079Ea, was derived from Ophioglossum pendulum (old world adder’s tongue fern) and has shown activity against corn rootworm when expressed by plants. An environmental risk assessment was conducted for corn event DP-915635, which provides control of corn rootworms (Diabrotica spp.) via expression of the IPD079Ea protein. DP915635 maize also contains the phosphinothricin acetyltransferase (PAT) protein, which confers tolerance to the herbicidal active ingredient glufosinate ammonium at current labeled rates, and the phosphomannose isomerase (PMI) protein which was used during the transformation of DP915635 maize as a selectable marker. This assessment focused on the protein IPD079Ea and characterized potential exposure and hazard to non-target organisms (NTOs). For exposure, estimated environmental concentrations (EECs) were calculated using the expected maximum concentrations of IPD079Ea protein in relevant corn tissues. For hazard, laboratory dietary toxicity studies were conducted with IPD079Ea protein and standard surrogate non-target organisms representing various functional groups, e.g., pollinators, predators, and soil-dwelling organisms. Environmental risk was characterized by comparing hazard and exposure to calculate the margin of exposure (MOE) for each of the functional groups. The risk assessment process for expressed proteins, including any exposure refinements, will be explained in detail.