New Harvard Forest Publication: Invasive Wood Wasp In Pine Stands

The European Wood Wasp (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, Harvard Forest Ecologist David Orwig, along with Kevin Dodds and Peter de Groot conducted stand surveys and measured attacked and unattacked trees from nine red pine (Pinus resinosa) and Scots pine (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, and in some P. resinosa stands, levels were greater in magnitude than S. noctilio losses. Data from this study suggests silvicultural treatments that focus enhanced stem vigor should be a key component to integrated pest management plans for S. noctilioin North America.

Dodds, K.J., P. de Groot, and D.A. Orwig. 2010. The impact of Sirex noctilio in Pinus resinosa and Pinus sylvestris stands in New York and Ontario. Canadian Journal of Forest Research. pp. 212-223.