Search tips
Search criteria 


Logo of procbThe Royal Society PublishingProceedings BAboutBrowse by SubjectAlertsFree Trial
Proc Biol Sci. 2003 September 22; 270(1527): 1905–1909.
PMCID: PMC1691461

Relative importance of predators and parasitoids for cereal aphid control.


Field experiments with manipulations of natural enemies of plant-feeding insects may show how a diverse enemy group ensures an important ecosystem function such as naturally occurring biological pest control. We studied cereal aphid populations in winter wheat under experimentally reduced densities of: (i) ground-dwelling generalist predators (mostly spiders, carabid and staphylinid beetles); (ii) flying predators (coccinellid beetles, syrphid flies, gall midges, etc.) and parasitoids (aphidiid wasps), and a combination of (i) and (ii), compared with open controls. Aphid populations were 18% higher at reduced densities of ground-dwelling predators, 70% higher when flying predators and parasitoids were removed, and 172% higher on the removal of both enemy groups. Parasitoid wasps probably had the strongest effect, as flying predators occurred only in negligible densities. The great importance of parasitism is a new finding for aphid control in cereal fields. In conclusion, a more detailed knowledge of the mechanisms of natural pest control would help to develop environmentally sound crop management with reduced pesticide applications.

Full Text

The Full Text of this article is available as a PDF (175K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
  • Hawkins BA, Cornell HV. Maximum parasitism rates and successful biological control. Science. 1994 Dec 16;266(5192):1886–1886. [PubMed]
  • Lang Andreas. Intraguild interference and biocontrol effects of generalist predators in a winter wheat field. Oecologia. 2003 Jan;134(1):144–153. [PubMed]
  • Rosenheim JA. Higher-order predators and the regulation of insect herbivore populations. Annu Rev Entomol. 1998;43:421–447. [PubMed]
  • Schmitz OJ, Hambäck PA, Beckerman AP. Trophic Cascades in Terrestrial Systems: A Review of the Effects of Carnivore Removals on Plants. Am Nat. 2000 Feb;155(2):141–153. [PubMed]
  • Symondson WOC, Sunderland KD, Greenstone MH. Can generalist predators be effective biocontrol agents? Annu Rev Entomol. 2002;47:561–594. [PubMed]
  • Thies C, Tscharntke T. Landscape structure and biological control in agroecosystems . Science. 1999 Aug 6;285(5429):893–895. [PubMed]
  • Tilman David, Cassman Kenneth G, Matson Pamela A, Naylor Rosamond, Polasky Stephen. Agricultural sustainability and intensive production practices. Nature. 2002 Aug 8;418(6898):671–677. [PubMed]

Articles from Proceedings of the Royal Society B: Biological Sciences are provided here courtesy of The Royal Society