| Popis: |
Previous investigations of mutualistic associations between ants and plants bearing extrafloral nectaries (EFNs) or between ants and trophobiont leafhoppers have studied these relationships separately, but nothing is known on how ant abundance responds to these two food resources occurring in the same habitat when that habitat is disturbed by fire. The objectives of this study are to document ant abundance with the trophobiont five-spotted gamagrass leafhopper, Dalbulus quinquenotatus DeLong & Nault, and with EFNs on trees of Acacia pennatula (Schlecht & Cham.) Benth. (Fabaceae) that occur in the same habitat, and how ant abundance in both of these mutualisms is affected after disturbance by fire. This study was performed at several sites in central Mexico where the perennial gamagrass Tripsacum dactyloides L. (Gramminae) and A. pennatula both occur. More ants were collected in association with the leafhopper D. quinquenotatus than with EFNs of A. pennatula. At sites where dry season fire occurred, new green leaves were produced by both T. dactyloides and A. pennatula after the burn. On these new leaves after fire, significantly more ants tended D. quinquenotatus leafhoppers on T. dactyloides than visited EFNs on A. pennatula. In burned sites the ants Anoplolepis gracilipes Smith, Brachymyrmex obscurior Forel and Pheidole sp. live in association with the leafhoppers, whereas EFNs on A. pennatula were associated with the ants A. gracilipes, B. obscurior, Camponotus sp., Crematogaster sp. and Solenopsis sp. |
