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Oecologia

, Volume 79, Issue 1, pp 136–139 | Cite as

Exclusion of birds from bilberry stands: impact on insect larval density and damage to the bilberry

  • Ola Atlegrim
Original Papers

Summary

The bilberry (Vaccinium myrtillus L.), is the dominant plant in the field layer of many boreal forests in northern Sweden. It is utilized by several herbivorous insect larvae as food (i.e. Lepidoptera: Geometridae, Tortricidae and Hymenoptera: Symphyta). Total density of insect larvae was 63% lower where birds had access to larvae compared to exclosures. Larvae with a feeding behaviour which exposes them to birds (geometrids and sawflies) showed a pronounced reduction in density when exposed to bird predators. Density of larvae with a concealed feeding behaviour (tortricids) was unaffected by birds. The frequency of larval damage to bilberry annual shoots was significantly higher in areas where larval density was high due to exclusion of birds. I concluded that birds have the potential to heavily modify the interaction between bilberry and insect larvae.

Key words

Predation Bird exclosure Three trophic level interaction Insect larvae Bilberry 

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Copyright information

© Springer-Verlag 1989

Authors and Affiliations

  • Ola Atlegrim
    • 1
  1. 1.Department of Wildlife EcologySwedish University of Agricultural SciencesUmeåSweden

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