Predatory bugs in hazelnut orchards of Piedmont and Sardinia (Italy)

The hazelnut agro-ecosystem is generally characterized by a high complexity and a relative stability in space and time, also due to its abundant arthropod fauna including several groups of beneficial organisms. Therefore the research was conducted to investigate the predatory insects belonging to Heteroptera on hazelnut in Piedmont (NW Italy) and in Sardinia. In 2005, predatory Heteroptera were fortnightly sampled in nine hazel groves: six intensively cropped in Piedmont and three unmanaged in Sardinia. Presence-and-Absence data achieved during field-surveys were analyzed applying the centroid clustering method. Predatory bug communities of Piedmont and Sardinia formed separate clusters. In both regions, the family Miridae was the most abundant and rich in species, with nine and eight species in the agro-ecosystems of Piedmont and Sardinia, respectively. Few species of the families Anthocoridae and Nabidae were collected: in most cases, they occurred occasionally and in low amounts in the investigated orchards.