Exploring stable pattern formation in models of tussock moth populations
Authored by WG Wilson, SP Harrison, A Hastings, K McCann
Date Published: 1999
DOI: 10.1046/j.1365-2656.1999.00265.x
Sponsors:
United States National Science Foundation (NSF)
Platforms:
No platforms listed
Model Documentation:
Other Narrative
Mathematical description
Model Code URLs:
Model code not found
Abstract
1. The western tussock moth (Orgyia vetusta) at the University of
California Bodega Marine Reserve (Sonoma County, California, USA)
exhibits dense, localized populations in the midst of extensive habitats
where variation in host plant quality or predator abundance is unable to
explain the restricted extent of the outbreaks.
2. Two primary features suggest that the host patterning is
intrinsically generated: (i) female tussock moths are wingless, producing a low effective dispersal distance for the hosts; and (ii) the
tussock moth population is attacked by several species of widely
dispersing wasp and fly parasitoids.
3. We consider a set of spatially explicit host-parasitoid models to
examine whether intrinsically generated patterns are possible within
this system. These models include a spatially extended Nicholson-Bailey
model to examine general features of pattern formation in
host-parasitoid systems, and two system-specific models, an
individual-based simulation and a population-level analytic model to
examine the details of this empirical system.
4. Both stable patterning and rapid extinction of the host population
are initial-condition dependent outcomes of the general and specific
models, implying that an intrinsically generated stable host pattern is
feasible within the tussock moth system.
5. Stable patterning is enhanced by a large parasitoid-to-host dispersal
ratio, local host resource limitation, and increased parasitism at the
host patch's edge.
Tags
Spatial dynamics
Dispersal
Aggregation
stability
Environments
Diffusion-model
Host-parasitoid systems
Lupine lupinus-arboreus
Predator-prey
dynamics
Orgyia-vetusta