Interactive effects of mycorrhizal fungi, salt stress, and competition on the herbivores of Baccharis halimifolia
Article first published online: 11 AUG 2009
© 2009 The Authors. Journal compilation © 2009 The Royal Entomological Society
Volume 34, Issue 5, pages 580–587, October 2009
How to Cite
YOUNGINGER, B., BARNOUTI, J. and MOON, D. C. (2009), Interactive effects of mycorrhizal fungi, salt stress, and competition on the herbivores of Baccharis halimifolia. Ecological Entomology, 34: 580–587. doi: 10.1111/j.1365-2311.2009.01105.x
- Issue published online: 9 SEP 2009
- Article first published online: 11 AUG 2009
- Accepted 20 April 2009First published online 11 August 2009
- exploitative competition;
- gall maker;
- within-trophic-level effects
1. Plant stress and association with mycorrhizal fungi have been shown to significantly influence plant quality, yet their roles in influencing plant–insect interactions remain unclear. Even less is known about how these factors might interact with or be modified by within-trophic level interactions.
2. In the present study, the results of a factorial field experiment are reported in which the effects of within-trophic-level interactions, plant stress, and mycorrhizae on three herbivores of Baccharis halimifolia were examined.
3. Plant stress was increased by adding salt to the soil, and availability of mycorrhizal fungi was increased by inoculating plant roots. These treatments were applied to plants with either low or high densities of a competitor (Trirhabda baccharidis).
4. For the two leaf miners, Amauromyza maculosa and Liriomyza trifolii, increased soil salinity and high densities of the competitor Trirhabdabaccharidis resulted in significant decreases in density. Neither of these treatments affected the gall maker Neolasioptera lathami.
5. Mycorrhizal fungi increased the densities of all three herbivores, possibly by increasing foliar nitrogen levels. For the two leaf miners, there was also evidence that mycorrhizae ameliorated the negative effects of salt stress. There was also evidence that high levels of competition dampened the positive effects of mycorrhizae on the two leaf miners.