Ciclo biologico e capacità riproduttiva diTomicus destruensin Sardegna

The pine shoot beetle,Tomicus destruensWoll. (Coleoptera Curculionidae), is the main pest of Mediterranean pine forests and causes high economic and environmental damages. Despite the numerous studies on its biology, the number of annual generations and "sister broods" is still uncertain. Therefore, life cycle and reproduction of the pine shoot beetle were investigated from 2009 to 2013 in pine stands of Sardinia [Pixinamanna (Pula), Curadureddu (Tempio Pausania), and Prigionette (Alghero)] characterized by different climatic conditions, latitude and altitude. Our findings defined the life cycle ofT. destruensin the Mediterranean area, showing that the reproductive attacks in the log started consistently in the first week of October and lasted until the beginning of May. Trunk attacks were not constant over time, showing the highest intensity in October-November and the lowest in February. In the warmest areas of Sardinia, the dispersal phase ofT. destruensimmature adults started in late March and showed a single emergence peak in mid May. Conversely, in the mountain area of Tempio Pausania, adult emergence was delayed by one month. In Sardinia,T. destruenscompleted one generation per year, because also early-emerging adults were unable to oviposit before the beginning of summer. However, the pine shoot beetle showed a long trunk attack period, which occurred because females created up to 4 breeding galleries per year.