EPPO Global Database

In USA, crop rotation is the main strategy to control Diabrotica virgifera virgifera (EPPO A2 quarantine pest). In Illinois and Indiana, rotation of maize with soybean is widely used. Economic damage to maize planted after soybean was rarely observed, and was only seen when populations of volunteer maize plants were abundant in soybean fields. However, since the late 1980s, in Illinois (east central part) and Indiana (north-western part), D. virgifera virgifera have been laying eggs in soybean fields regardless of the presence of volunteer maize plants, and economic damage to maize planted after soybean has become common. Laboratory studies were carried to compare the attractiveness of soybean, corn and associated crop environments to D. virgifera virgifera from north-western Indiana with beetles from other areas (Iowa and Nebraska). Results of laboratory studies (multiple choice and no-choice feeding assays) indicated that a variant of D. virgifera virgifera may be present in a portion of the population present in the north-western part of Indiana and that this variant preferred soybean environment to maize environment. If these results were to be verified in the field, this would have consequences on control strategies, as the reliability of crop rotation with soybean would be diminished in areas where this variant occurs.