Invasion speed is affected by geographic variation in the strength of Allee effects
Patrick Tobin, email@example.com, Stefanie Whitmire2, Derek Johnson3, Ottar Bjørnstad4, and Andrew M. Liebhold1. (1) USDA Forest Service, Northeastern Research Station, 180 Canfield Street, Morgantown, WV, (2) University of Puerto Rico – Mayagüez, Department of Agronomy and Soils, PO Box 9030, Mayagüez, PR, PR, (3) University of Louisiana, Department of Biology, P.O. Box 42451, Lafayette, LA, (4) Pennsylvania State University, Department of Entomology, 501 ASI Building, University Park, PA
Allee effects can play a critical role in slowing or preventing the establishment of low density founder populations of nonindigenous species. Similarly, the spread of established invaders into new habitats is influenced by the degree to which small founder populations ahead of the invasion front are suppressed through Allee effects. We used empirical data on the gypsy moth, an exotic invader in North America, to quantify the Allee threshold across geographic regions and report that its strength is subject to spatial and temporal variability. Moreover, we present what is to our knowledge the first empirical evidence that geographic regions with higher Allee thresholds are associated with slower speeds of invasion.
Species 1: Lepidoptera Lymantriidae Lymantriadispar (gypsy moth)