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Harvard Forest Symposium Abstract 2010

  • Title: The impact of Sirex noctilio in Pinus resinosa and Pinus sylvestris stands in north central North America
  • Primary Author: David Orwig (Harvard Forest)
  • Additional Authors: Kevin Dodds (USDA Forest Service); Peter de Groot (Natural Resources Canada)
  • Abstract:

    The European woodwasp (Sirex noctilio), has a long history as an invasive insect species in exotic pine plantations throughout the southern hemisphere and has been recently discovered in north central North America. It is uncertain how this insect will behave in pine ecosystems in North America. To assess the impact and attack behavior of S. noctilio, forest stand surveys and measurements from attacked and unattacked trees were taken in nine Pinus resinosa and P. sylvestris plantations located in New York, USA, and Ontario, Canada. There was a trend of S. noctilio attacking suppressed trees that had 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. Sirex noctilio appeared to have more of an impact in P. sylvestris forests, as they attacked more stems (9-18%) and higher basal area (1.6-5.5 m2/ha-1) than P. resinosa stands (3-8% of stems and 0.4 2.4 m2/ha-1). Dead trees with signs of Siricidae present and dead from other causes were also quantified in these stands, and in some P. resinosa stands, levels were greater in magnitude than S. noctilio losses. Data from this study suggests silvicultural treatments that focus on increasing tree vigor should be a key component to integrated pest management plans for S. noctilio in North America.

  • Research Category: Invasive Plants, Pests & Pathogens