Abstract

It has been claimed that natural enemies of pests perform important ecosystem services in agricultural landscapes. These services have rarely been evaluated in yield or monetary terms at farm level. We have examined the degree to which ground-living natural enemies of the bird cherry-oat aphid (Rhopalosiphum padi (L.)) reduced aphid abundance and influenced barley yields on ten commercial farms in central Sweden. On average, ground-living natural enemies of pests increased barley yields by 303 kg/ha. This corresponded to a potential 52% reduction in yield loss from R. padi compared with a scenario where no natural enemies were present. Measured as the percentage increase of actual yield, ground-living natural enemies of aphids increased the yield by 23%. The increase in yields in absolute terms was larger on conventional farms than organic farms, but the percentage increase of yields was larger on organic farms. The study only considered I year, with high aphid abundance. However, we also discuss the effects of predators as well as insecticides in the long-term. Our study shows that yield increases attributable to predators can be compared with yield increases from insecticide use for the evaluation of different management strategies. (C) 2003 Elsevier Science B.V. All rights reserved

Published in

Ecological Economics
2003, Volume: 45, number: 1, pages: 149-158
Publisher: ELSEVIER SCIENCE BV

SLU Authors

• Ekbom, Barbara

  • Department of Entomology, Swedish University of Agricultural Sciences
    

• Bengtsson, Jan

  • Department of Ecology and Crop Production Sciences, Swedish University of Agricultural Sciences
    

• Östman, Örjan

  • Department of Ecology and Crop Production Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science


Publication identifier

DOI: https://doi.org/10.1016/S0921-8009(03)00007-7

Permanent link to this page (URI)

https://res.slu.se/id/publ/1136