The Effects of Mutualism with Ants on Antianthe Expansa, A Neo-Tropical Treehopper (Membracidae: Homoptera)
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Authors
Ferguson, Bruce G.
Issue Date
1989
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
Interactions between membracids and ants are highly variable.
Mutualism may significantly increase membracid survivorship and
the magnitude of the increase may depend on the species of
attendant ant. This study examines the mutualism between
Antianthe expansa and several species of ants at a study site in
Monteverde, Costa Rica. Differences among behaviors of attendant
ant species were observed and quantified. A census of twenty host
plants demonstrated that Pheidole sp. maintain significantly higher
ant to membracid ratios than Crematogaster nigropilosa,
Myrmelachista zeledoni, or Pheidole biconstricta (t-test, p<0.05).
Furthermore, Pheidole were shown to be more aggressive than C.
nigropilosa in driving off potential competitors of A. expansa.
Pheidole attacked and dismantled adults of Alchisme grossa, a nontended
membracid, which were pinned to the host plants, while C.
nigropilosa ignored the intruders. A survivorship study was carried
out to compare mortality of nymphs on tended plants with mortality
of nymphs on plants from which ants had been excluded. T-tests
between regression coefficients of survivorship plots showed
significantly higher (p<0.0l) survival rates on tended plants, with
aggregations tended by Pheidole showing higher survival rates than
others. In conclusion, mutualism with ants can significantly increase
A. expansa survival rates. Pheidole ants, by virtue of maintaining
greater ant to membracid ratios and greater aggression toward
competitors and predators of A. expansa, cause a greater increase In
survivorship than the other ants found at the study site.
Description
vi, 25 p.
Citation
Publisher
Kalamazoo College
License
U.S. copyright laws protect this material. Commercial use or distribution of this material is not permitted without prior written permission of the copyright holder.