Strategie di controllo della Diabrotica del mais (Diabrotica virgifera virgifera)

The western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), is one of the most important pest species of maize (Zea mays L.) in the United States and in several countries of central and eastern Europe. Although the adults can sometimes be harmful, larval damage is usually most severe. Most injury is done by the larvae which feed on the root hairs and tissues causing the loss of stability of the plants, which become extremely prone to lodging. Field experiments were performed in the two-year period 2010-2011 in Piedmont and Lombardy regions (NW Italy), with the aim to determine the beetle infestation, the root damage, and the grain yield. The effect of agronomic techniques such as different sowing times, soil insecticides application, agronomic practices were compared to untreated plants. The average number of larvae recorded in Piedmont was 1.8 and 1.4 and in Lombardy 5.5 and 10.2, in 2010 and 2011, respectively. The application of soil insecticide showed an increase of grain yield, while contradictory results were found with regard to the larval infestation.