TRANSGENIC CORN EXPRESSING A CRY9C INSECTICIDAL PROTEIN FROM BACILLUS-THURINGIENSIS PROTECTED FROM EUROPEAN CORN-BORER DAMAGE

The European corn borer, Ostrinia nubilalis (Hubner), is a devastating insect pest in tile corn (Zea mays L.) growing regions of North Ameri ca and Europe, Field evaluations in the USA and Belgium showed that tr ansgenic corn events expressing Cry9C, an insecticidal crystal protein from Bacillus thuringiensis subsp, tolworthi, very effectively contro l both generations of the European corn barer, Second to fourth instar larvae fed with leaf material of event CBH351 expressing the Cry9C pr otein air died within 4 d. Cry9C events, expressing high levers of the insecticidal protein, showed minimal stalk tunneling after heavy arti ficial infestations. Event CBH351 tested in plots containing only Cry9 C transgenic plants had 0.14- and 0.09-cm tunneling per stalk compared with more than 30- and 23-cm tunneling par stalls Tor the negative co ntrols, inn tile Belgium and Iowa field trial, respectively. In plots containing 30% non-transgenic plants the event CBH351, showed only 1.4 5-cm tunneling per stalk. Leaf, tassel, and pith tissue contained 39.0 , 17.4, and 84.8 mu g Cry9C protein mg(-1) soluble protein, respective ly, in analyses conducted at harvest of the Belgium trial. The implica tions of Cry9C use for resistance management strategies sue discussed.