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Global biogeography of Sirex noctilio with emphasis on North America

Informally Refereed

Abstract

Sirex noctilio is a Eurasian species in the woodwasp (Siricidae) insect family, a small and poorly understood group of insects. Several siricid species have invaded various world regions due to their frequent presence in wood moving in international trade. Like most other woodwasps, feeding by S. noctilio occurs in weakened or dying pines in its native range, and populations exist there at relatively low levels. But in non-native regions of the Southern Hemisphere, S. noctilio populations have thrived, colonizing hosts in plantations of non-native pines planted at high densities. Under such conditions, S. noctilio reproduction can drive populations to epidemic densities, causing considerable tree mortality. Invasions in the Southern Hemisphere started with colonization of New Zealand around 1900, then Australia in 1952, South America in 1980, and South Africa in 1994. Given the reputation of S. noctilio as a successful invader and its repeated interception from imported cargo at ports, invasion of North America by this species was greatly anticipated with caution. Those fears came true when it was detected in a trap placed in New York near Lake Ontario in 2004. Subsequent delimitation surveys, and discovery of larvae within trees, confirmed the presence of the species over a large 19-county area, indicating that populations had been present for many years and eradication was considered infeasible. Subsequently, S. noctilio has been found in nine northeastern US states and two eastern Canadian provinces and appears to be expanding its range. To date, however, populations in North America remain low and have caused little damage, similar to what is seen throughout most of its native range. Large regions of pine-dominated forests are still likely to be invaded, but it is not clear whether these regions are climatically suitable and whether populations will continue to remain at low densities as it spreads into regions with abundant pine forests.

Citation

Liebhold, Andrew M.; Hajek, Ann E. 2021. Global biogeography of Sirex noctilio with emphasis on North America. In: Hajek, Ann E.; Haavik, Laurel J.; Stephen, Fred M., eds. Biology and Ecology of Sirex noctilio in North America. Morgantown, West Virginia: USDA Forest Service, Forest Health Assessment and Applied Sciences Team. FHAAST-2019-01. 1-8. Chapter 1.
https://www.fs.usda.gov/research/treesearch/63353