Allee effects and pulsed invasion by the gypsy moth

Derek M. Johnson, Andrew M. Liebhold, Patrick C. Tobin, Ottar N. Bjørnstad

Research output: Contribution to journalArticlepeer-review

194 Scopus citations


Biological invasions pose considerable threats to the world's ecosystems and cause substantial economic losses. A prime example is the invasion of the gypsy moth in the United States, for which more than $194 million was spent on management and monitoring between 1985 and 2004 alone. The spread of the gypsy moth across eastern North America is, perhaps, the most thoroughly studied biological invasion in the world, providing a unique opportunity to explore spatiotemporal variability in rates of spread. Here we describe evidence for periodic pulsed invasions, defined as regularly punctuated range expansions interspersed among periods of range stasis. We use a theoretical model with parameter values estimated from long-term monitoring data to show how an interaction between strong Allee effects (negative population growth at low densities) and stratified diffusion (most individuals disperse locally, but a few seed new colonies by long-range movement) can explain the invasion pulses. Our results indicate that suppressing population peaks along range borders might greatly slow invasion.

Original languageEnglish (US)
Pages (from-to)361-363
Number of pages3
Issue number7117
StatePublished - Nov 16 2006

All Science Journal Classification (ASJC) codes

  • General


Dive into the research topics of 'Allee effects and pulsed invasion by the gypsy moth'. Together they form a unique fingerprint.

Cite this