The attack and methods of prevention and combat of the species Diabrotica virgifera virgifera le conte in the conditions of Central Moldova

Abstract

The species Diabrotica virgifera virgifera Le Conte (western corn rootworm) is part of the order Coleoptera, family Chrysomelidae. Originally from North America, it entered in Europe in 1992, and in Romania in 1996. Both adults and larvae of this species are harmful, with the adults attacking the aerial parts of the plant (leaves, panicle, silk, pollen and milk stage berries) and the larvae causing root damage (Moeser and Hibbard, 2005). To recognize plants attacked by larvae, a preventive assessment can be made regarding the characteristic symptomatology of the stem, namely "swan neck" (Krysan and Miller, 1986). In the conditions of Central Moldova, in the year 2024, the average number of larvae per plant ranged from 1 to 7, and the frequency of swan neck symptom ranged from 0% to 44.7%. The average attack frequency produced by adults on leaf was 59%, and on silk 89%. The average number of adults per plant recorded values between 3.8 and 7.1 before the chemical treatment was applied to the vegetation, which was reduced to 0.2 adults per plant after the application of the treatment. The efficacy of insecticides was between 96.6% and 97.2%.