NCEAS Project 2250

Predators, pathogens, and parasitoids as mortality agents in phytophagous insect populations

  • Howard V. Cornell
  • Bradford A. Hawkins


ActivityDatesFurther Information
Working Group1st—10th June 1996Participant List  
Working Group14th—28th September 1996Participant List  
Working Group30th March—5th April 1998Participant List  

Abstract
Insect herbivores are killed by a diverse array of natural enemies, however not all herbivores suffer enemy attacks to the same degree. Various ecological and biological factors influence the rate of enemy-induced mortality suffered by herbivore populations. The major goal of this project is to quantify the effects of these factors on enemy-induced mortality, as revealed by a life table database of holometabolous herbivores. Although enemy mortality will be emphasized, we will also examine mortality caused by weather, competition, and plant factors. A secondary goal will be to compile and analyze a life table database of hemimetabolous herbivores. All databases will be made available to other workers when the analysis is complete. Enemy-induced mortality will be characterized by type (predator, parasitoid, or pathogen), and the relative importance of each type as well as other causes of death will be tested for differences associated with five ecological characteristics of the herbivores (feeding biology, invasion status, and the successional stage, cultivation status, and latitudinal zone of the habitat). The information will also reveal if herbivore ecology affects all enemies equally, or if tradeoffs exist such that reductions in the rate of attack by one type of enemy may be offset by increased attacks by other types. If so, than the already complex dynamics identified for plant vs. enemy interactions may be further enriched by interactions among the enemies themselves.

TypeProducts of NCEAS Research
Presentations Cornell, Howard V. 1996. Towards an empirically-based theory of herbivore demography. International Congress of Entomology. Florence, Italy.
Presentations Cornell, Howard V. 1997. Towards an empirically-based theory of herbivore demography. Cornell University. Ithaca, NY.
Presentations Cornell, Howard V. 1997. Towards an empirically-based theory of herbivore demography. Ecological Society of America Annual Meeting. Albuquerque, NM.
Presentations Cornell, Howard V. 1997. Towards an empirically-based theory of herbivore demography. Bodega Marine Laboratory. Bodega Bay, CA.
Report or White Paper Cornell, Howard V.; Hawkins, Bradford A. 1998. Summary of Hawkins and Cornell NCEAS Working Group. (Online version)
Presentations Cornell, Howard V. 1998. Towards an empirically-based theory of herbivore demography. University of California, Davis. Davis, CA.
Journal Article Cornell, Howard V.; Hawkins, Bradford A.; Hochberg, Michael E. 1998. Towards an empirically-based theory of herbivore demography. Ecological Entomology. Vol: 23. Pages 340-349.
Presentations Cornell, Howard V. 1998. Towards an empirically-based theory of herbivore demography. University of British Columbia. Canada.
Journal Article Cornell, Howard V.; Hawkins, Bradford A. 2003. Herbivore responses to plant secondary compounds: A test of phytochemical coevolution theory. American Naturalist. Vol: 161(4). Pages 507-522.
Journal Article Hawkins, Bradford A.; Cornell, Howard V.; Hochberg, Michael E. 1997. Predators, parasitoids, and pathogens as mortality agents in phytophagous insect populations. Ecology. Vol: 78. Pages 2145-2152.
Book Chapter Karlson, Ronald H.; Cornell, Howard V. 1997. Local and regional processes as controls of species richness. Edited by Tilman, David; Kareiva, Peter. Spatial Ecology: The Role of Space in Population Dynamics and Interspecific Interactions. Princeton University Press. Princeton. Pages 250-268.