I conducted this study for two years in a community of the gamagrass Tripsacum dactyloides in Central Mexico, where ants (Brachymyrmex obscurior) feed on the honeydew excreted by the myrmecophilous leafhopper Dalbulus quinquenotatus and the nectar produced by the extrafloral nectaries (EFNs) of Acacia pennatula. The objectives of this study were to assess whether the ant-tended homopteran and EFNs-bearing plant co-occur and determine whether ants protect the plant bearing EFNs. Ants did not always tend D. quinquenotatus on its gamagrass. Ants visited mainly active EFNs of A. pennatula when the gamagrass died out and the D. quinquenotatus population disappeared at the end of the dry season. Exclusion experiments showed that ants received food from the EFNs, but A. pennatula did not receive a protective benefit when visited by ants. Branches with and without ants had similar numbers of the non myrmecophile leafhopper Siboviasp. Branches with artificial damage and branches without damage had no difference in the number of ants and EFNs. Therefore, ants only use the plant exudates as a food resource during the end of the dry season.
Species 1: Homoptera Cicadellidae Dalbulus quinquenotatus
Species 2: Hymenoptera Formicidae Brachymyrmex obscurior
Keywords: mutualism, honeydew-nectar
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