The impact of Sirex noctilio in Pinus resinosa and Pinus sylvestris stands in New York and Ontario

Sirex noctilio Fabricius has a long history as an invasive insect species in pine plantations throughout the Southern Hemisphere and has been recently discovered in North America, where it is uncertain how this insect will behave in pine ecosystems To assess the impact and attack behavior of S. noctilio, forest surveys and measurements from attacked and unattacked trees were taken in nine Pinus resinosa Alt. and Pinus sylvestris L. plantations in New York, USA, and Ontario, Canada There was a trend of S noctilio attacking suppressed trees with smaller live crowns and reduced growth Some S noctilio attacks were also found in dominant crown classes but at a lower rate than overtopped or intermediate classes. Strex noctilio appeared to have more of an impact in P. sylvestris forests, as they attacked more stems (9%-18%) and higher basal area (16-55 m(2)/ha) than P. restinosa stands (3%-8% of stems and 0.4-24 m(2)/ha) Dead trees with signs of Siricidae and dead from other causes were also quantified. and in some P restinosa stands, levels were greater in magnitude than S noctilio losses. Data from this study suggest that silvicultural treatments should be a key component of integrated pest management plans for S noctilio