Host Suppression and Stability in a Parasitoid-Host System: Experimental Demonstration
William Murdoch,1*
Cheryl J. Briggs,2
Susan Swarbrick1
We elucidate the mechanisms causing stability and severe resource
suppression in a consumer-resource system. The consumer, the
parasitoid
Aphytis, rapidly controlled an experimentally induced
outbreak of the resource, California red scale, an agricultural
pest, and imposed a low, stable pest equilibrium. The results
are well predicted by a mechanistic, independently parameterized
model. The key mechanisms are widespread in nature: an invulnerable
adult stage in the resource population and rapid consumer development.
Stability in this biologically nondiverse agricultural system
is a property of the local interaction between these two species,
not of spatial processes or of the larger ecological community.
2 Department of Integrative Biology, University of California, Berkeley, CA 94720–3140, USA.
* To whom correspondence should be addressed. E-mail: murdoch{at}lifesci.ucsb.edu
