Contributing Authors. Preface. 1. The influence of intraguild predation on the suppression of a shared prey population: an empirical reassessment; J.A. Rosenheim and J.P. Harmon. 2. Intraguild predation usually does not disrupt biological control; A. Janssen et al.. 3. Multiple predator interactions and food-web connectance: implications for biological control; R.F. Denno and D.L. Finke. 4. Inter-guild influences on intra-guild predation in plant-feeding omnivores; D.R. Gillespie and B.D. Roitberg. 5. Trophic and guild interactions and the influence of multiple species on disease; M.B. Thomas et al.. 6. Intra- and interspecific interactions among parasitoids: mechanisms, outcomes and biological control; G. Boivin and J. Brodeur. 7. Indirect effects, apparent competition and biological control; F.J.F. van Veen et al.. 8. Ant-hemipteran mutualisms: keystone interactions that alter food web dynamics and influence plant fitness; M.D. Eubanks and J.D. Styrsky. 9. Interspecific competition among natural enemies and single versus multiple introductions in biological control; N. Mills. 10. Experimental approaches to understanding the relationship between predator biodiversity and biological control; C.S. Straub and W.E. Snyder. Index.