Some Data to the Risk Analysis of Bt-corn Pollen and Protected Lepidoptera Species in Hungary

Béla Darvas, Atilla Csóti, Adel Gharib, László Peregovits, László Ronkay, Éva Lauber and László A. Polgár

Some data to the risk analysis of Bt-corn pollen and protected Lepidoptera species in Hungary

Translated article: original page (figures) see in the Hungarian part of the webpage!

Risk assessment of the potential impact of Bt-corn pollen on protected Lepidoptera species in Hungary was studied. Pollination of the DK-440 BTY (event MON 810) occurs 74-88 day after sowing, and yielded 35 kg/hectare of pollen. The pollination of the cultivated corn varieties is in July to mid August in Hungary. Pollen density dropped under 100 pollen/cm2 at 5 m from the arable edge. Young caterpillars feeding on weeds nearly or in the cornfield might be affected. Pollen-deposition is the most effective on plants with broad, hairy and horizontal leaves. The leaf area/leaf weight ratio of the great nettle, Urtica dioica L. (Urticaceae) is 2.85 times higher than that of common milkweed, Asclepias syriaca L. (Asclepiadaceae), which might mean approximately 3 times higher toxin consumption at same pollen density. In Hungary, law protects 187 Lepidoptera species. 16% of them might feed on weeds growing at the edge of cornfields. We proved that Inachis io (L.) and Vanessa atalanta (L.) (Nymphalidae) might be affected by Bt-pollen. Both species feed on great nettle, a common weed in the water furrows of cornfields in Hungary. The eggs of these species hatch exactly at the time of corn pollination.