Allee effects and pulsed invasion by the gypsy moth

  title={Allee effects and pulsed invasion by the gypsy moth},
  author={Derek M. Johnson and Andrew M. Liebhold and Patrick C. Tobin and Ottar N. Bj{\o}rnstad},
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… 

The role of Allee effects in gypsy moth, Lymantria dispar (L.), invasions

The role of Allee effects in the establishment and spread dynamics of the gypsy moth system is explored, which conceptually could serve as a model system for understanding howAllee effects manifest themselves in the dynamics of biological invasions.

Biological invasion and biological control: A case study of the gypsy moth spread

This paper considers how the pattern of the gypsy moth spread can be affected by biological control when an infectious disease is introduced in the wake of the spreading species and finds that, rather counter-intuitively, the invasion success depends on the magnitude of the controlling effort in a non-monotonous way.

Modelling biological invasions : population cycles, waves and time delays

An alternative hypothesis to explain the patchiness of gypsy moth spread entailing the interplay between dispersal, predation or a viral infection and the Allee e ect is proposed and the onset of spatiotemporal chaos in the wake of population fronts is shown.

Long-Distance Dispersal of the Gypsy Moth (Lepidoptera: Lymantriidae) Facilitated Its Initial Invasion of Wisconsin

It is submitted that long-distance dispersal played an important role in the spread dynamics of the initial Wisconsin gypsy moth invasion, but it currently plays a lesser role because the portion of Wisconsin most susceptible to long- distance immigrants from alternate sources is now heavily infested.

Dispersal polymorphism in an invasive forest pest affects its ability to establish.

  • C. RobinetA. Liebhold
  • Environmental Science
    Ecological applications : a publication of the Ecological Society of America
  • 2009
The interacting effects of dispersal and Allee effects on both invasion processes are explored, via simulation, and strategies for managing invasions should be adjusted for the interactions betweenAllee effects and dispersal.

Critical patch size generated by Allee effect in gypsy moth, Lymantria dispar (L.)

This study is believed to be the first empirical documentation of critical patch size induced by an Allee effect, and confirmed here using a mechanistic model developed for the gypsy moth system.

Population ecology of insect invasions and their management.

During the establishment phase of a biological invasion, population dynamics are strongly influenced by Allee effects and stochastic dynamics, both of which may lead to extinction of low-density

Novel insights on population and range edge dynamics using an unparalleled spatiotemporal record of species invasion.

How data from a large-scale pest management programme have provided important contributions to the fields of population dynamics and invasion biology is reviewed.

Population Ecology of Managing Insect Invasions

This chapter focuses on the establishment and spread phases with consideration of how population processes operating during each stage influence the selection of management strategies.



Persistence of invading gypsy moth populations in the United States

It is proposed that differences in region-specific rates of persistence may be attributed toAllee effects that are differentially expressed in space, and that the inclusion of geographically varying Allee effects into colony-invasion models may provide an improved paradigm for addressing the establishment and spread of gypsy moth and other invasive exotic species.

Gypsy moth invasion in North America: a quantitative analysis

The gypsy moth, Lymantria dispar (L.), was accidentally introduced to North America in 1868 or 1869. Since that time, the range of this insect has spread to include most of the northeastern states in

Dispersal, Population Growth, and the Allee Effect: Dynamics of the House Finch Invasion of Eastern North America

A mathematical model is constructed that postulates that an Allee effect-disproportionately lowered fecundity below a critical threshold density of abundance-is the mechanism leading to a slower rate of spread in the early stages of the invasion.

“Slow The Spread”: A National Program to Contain the Gypsy Moth

The "Slow the Spread" project is a combined federal and state government effort to slow gypsy moth spread by detecting isolated colonies in grids of pheromone-baited traps placed along the expanding population front from Wisonsin to North Carolina.


The deterministic model demonstrates a novel way of representing density dependence and an Allee effect in population biology and could be applied to model the population dynamics of any species that spreads from multiple foci and in which these foci later coalesce.

Allee Effects, Invasion Pinning, and Species’ Borders

The properties of invasion models when a species cannot persist below a critical population density known as an “Allee threshold” are studied, suggesting caution when interpreting abrupt range limits as stemming either from competition between species or a hard environmental limit that cannot be crossed.


A model that assumes establishment of isolated colonies beyond the expanding population front, which estimates the rate of spread from two functions: colonization rate as a function of the distance from the population front and population numbers in a colony as afunction of colony age.

Circumpolar variation in periodicity and synchrony among gypsy moth populations

It is suggested that previous reports of interspecific synchrony among insects at scales much greater than 1000 km may suffer from spurious correlations among oscillating populations.


The model shows that slowing population spread is a viable strategy of pest control even when a relatively small area remains uninfested and is applied to managing the spread of gypsy moth populations in the United States.