The devil to pay: a cost of mutualism with Myrmelachista schumanni ants in 'devil's gardens' is increased herbivory on Duroia hirsuta trees - PubMed (original) (raw)

The devil to pay: a cost of mutualism with Myrmelachista schumanni ants in 'devil's gardens' is increased herbivory on Duroia hirsuta trees

Megan E Frederickson et al. Proc Biol Sci. 2007.

Abstract

'Devil's gardens' are nearly pure stands of the myrmecophyte, Duroia hirsuta, that occur in Amazonian rainforests. Devil's gardens are created by Myrmelachista schumanni ants, which nest in D. hirsuta trees and kill other plants using formic acid as an herbicide. Here, we show that this ant-plant mutualism has an associated cost; by making devil's gardens, M. schumanni increases herbivory on D. hirsuta. We measured standing leaf herbivory on D. hirsuta trees and found that they sustain higher herbivory inside than outside devil's gardens. We also measured the rate of herbivory on nursery-grown D. hirsuta saplings planted inside and outside devil's gardens in ant-exclusion and control treatments. We found that when we excluded ants, herbivory on D. hirsuta was higher inside than outside devil's gardens. These results suggest that devil's gardens are a concentrated resource for herbivores. Myrmelachista schumanni workers defend D. hirsuta against herbivores, but do not fully counterbalance the high herbivore pressure in devil's gardens. We suggest that high herbivory may limit the spread of devil's gardens, possibly explaining why devil's gardens do not overrun Amazonian rainforests.

PubMed Disclaimer

Figures

Figure 1

Figure 1

Standing level of leaf herbivory (±s.e.) on D. hirsuta with A. depilis, D. hirsuta with M. schumanni outside devil's gardens and D. hirsuta with M. schumanni inside devil's gardens. Different letters show statistically significant differences among treatments according to Tukey–Kramer post hoc tests (p<0.05).

Figure 2

Figure 2

Standing level of leaf herbivory (±s.e.) on _M. schumanni_-occupied D. hirsuta plotted against the number of D. hirsuta trees occupied by the M. schumanni colony. The solid line is the regression relationship (_r_2=0.49, _p_=0.05).

Figure 3

Figure 3

Herbivory rate per day (±s.e.) on D. hirsuta saplings planted outside devil's gardens, outside devil's gardens with ants excluded, inside devil's gardens and inside devil's gardens with ants excluded. Different letters show statistically significant differences among treatments according to Tukey–Kramer post hoc tests (p<0.05).

Similar articles

Cited by

References

    1. Adler F.R, Muller-Landau H.C. When do localized natural enemies increase species richness? Ecol. Lett. 2005;8:438–447. doi:10.1111/j.1461-0248.2005.00741.x - DOI
    1. Andow D.A. Vegetational diversity and arthropod population response. Annu. Rev. Entomol. 1991;36:561–586. doi:10.1146/annurev.en.36.010191.003021 - DOI
    1. Blundell A.G, Peart D.R. Distance-dependence in herbivory and foliar condition for juvenile Shorea trees in Bornean dipterocarp rain forest. Oecologia. 1998;117:151–160. doi:10.1007/s004420050643 - DOI - PubMed
    1. Boucher D.H, James S, Keeler K.H. The ecology of mutualism. Annu. Rev. Ecol. Syst. 1982;13:315–347. doi:10.1146/annurev.es.13.110182.001531 - DOI
    1. Breton L.M, Addicott J.F. Density-dependent mutualism in an ant–aphid interaction. Ecology. 1992;73:2175–2180. doi:10.2307/1941465 - DOI

Publication types

MeSH terms

LinkOut - more resources