title: The effect of multiple parasitoid introductions upon the equilibrium value of host density.
abstract: Four models of host-parasitoid population variation are examined to study the effect of additional parasitoid introductions. Only one of the models predicts that the equilibrium value of host population increases with such introductions. The other three, that of Holling, of Nicholson, and its recent modification by Hassell and Varley, predict a fall in the equilibrium of host numbers. Thus it would appear that the practice of multiple introductions in biological control is correct when the host-parasitoid relationship can be modelled by these latter systems.
authors.affiliation: Department of Mathematics, University of Queensland, Brisbane.
authors.forename: Phil
authors.initials: P
authors.lastname: Diamond