Neotropical Entomology

, Volume 42, Issue 3, pp 223–229

Common-Garden Experiments Reveal Geographical Variation in the Interaction Among Crotalaria pallida (Leguminosae: Papilionideae), Utetheisa ornatrix L. (Lepidoptera: Arctiidae), and Extrafloral Nectary Visiting Ants

Ecology, Behavior and Bionomics

DOI: 10.1007/s13744-013-0114-8

Cite this article as:
Franco, M.S. & Cogni, R. Neotrop Entomol (2013) 42: 223. doi:10.1007/s13744-013-0114-8


The study of geographical variation is a key approach to understand evolution of ecological interactions. We investigated geographical variation in the interaction among Crotalaria pallida (Leguminosae: Papilionideae), its specialized herbivore, Utetheisa ornatrix L. (Lepidoptera: Arctiidae), and ants attracted to extrafloral nectaries (EFNs). First, we used common-garden experiments with plants collected in different sites at different geographical scales to test for differences among populations in C. pallida attractiveness to ants. When we compared three populations from Southeast Brazil (150 km apart), the number of visiting ants per plant, and the percent of termite baits attacked by ants, were significantly different among plant populations. In a comparison of populations from SE Brazil and Florida (USA), there was no significant difference between the populations in the number of ants per plant or the frequency of baits attacked. Second, we tested in a common garden if U. ornatrix larvae present any behavior to avoid ant predation, and if there were genetic differences among populations. We observed that most larvae moved away from the vicinity of the EFNs (flowers and fruits) to the plant leaves. Of the larvae that moved to leaves, only 10% were attacked by ants while 89% of larvae that stayed near the fruit/flower were attacked. There was a significant difference among populations in the frequency of larvae that moved to the leaves and the frequency of larvae attacked by ants. We discuss the possible causes of the geographical differences observed and propose future research directions in this system.


Ant–plant interactioncoevolutionherbivorymutualismpredation

Copyright information

© Sociedade Entomológica do Brasil 2013

Authors and Affiliations

  1. 1.Depto de Biologia Animal, Instituto de BiologiaUniv Estadual de CampinasCampinasBrasil
  2. 2.Dept of Ecology and EvolutionStony Brook UnivStony BrookUSA
  3. 3.Dept of GeneticsUniv of CambridgeCambridgeUK