Effectiveness of entomopathogenic nematodes in the control of Cydia pomonella larvae in Northern Italy

Since 2006, a large scale research on the effectiveness of entomopathogenic nematodes (EPN) in the control of codling moth (CM), Cydia pomonella, overwintering larvae has been performed on about 35 ha of pear orchards per year in Emilia-Romagna, Northern Italy. Steinernema carpocapsae and Steinernema feltiae activity was checked after spray applications of EPNs to the trunk and branches. In 2006, the treatment was applied either in spring or in autumn at different doses, before CM pupation; in 2007 the EPN treatment was applied only in autumn at 1.5 x 109 I.J. ha –1. Every year it was distributed by means of a conventional mist blower. The larval mortality was assessed directly on sentinel larvae in card boards on the trunks and indirectly on the eggs laid by the females of the first CM generation in spring. Moreover, each year, a trial was performed applying only S. carpocapsae on sentinel larvae with the aim of testing this nematode at suitable temperatures but at different water volumes. The CM sentinel larvae were effectively parasitized after autumnal EPN application. Moreover, the egg assessment demonstrated a good decrease in CM population in spring 2007, when EPNs had been applied at the best weather conditions (t° 12-14 °C and rain) in the previous autumn