Resumen de Some factors influencing colony spacing and survival in the grass-cutting ant Acromyrmex landolti fracticornis (Forel) (Formicidae: Attini) in Paraguay
- español
Algunos factores que afectan los patrones espaciales de las colonias de la hormiga gramnívora Acromyrmex landolti fracticornis (Forel) son considerados bajo condiciones naturales. La agresión entre colonias Y. quizá, la ejecución de las reinas incipientes podrán tener mucha importancia. Los territorios de forrajeo se orientan linealmente, dividiendo los recursos disponibles en un mosaico. La distancia forrajeada por las hormigas es función del tamaño de la colonia. Las actividades del mantenimiento de la colonia, tales como la construcción del túmulo y la formación de un basurero superficial, afectan la supervivencia de malezas. Con la disminución de la cobertura de pastos y el aumento de la de malezas, las densidades dc colonias decayeron significativamente.
- English
Various aspects of the ecology of the Paraguayan grass-cutting ant, Acromyrmex Iandolti fracticornis (Forel), were studied in the field. Colonies were found lo linearly orient their foraging territories, partitioning the habitat in a mosaic pattern. The distance foraged by workers were found to be a function of colony size: (Log10 maximum distance foraged) = -0,5156 + 0.4121 (Log10 area of nest). Colony .pacing, however, was found to be not immediate y dependent on colony size. Colony spacing patterns are influenced by intra-specific aggression, and perhaps by the predation or execution of founding queens. Both the mound and superficial detritus heap of nests were found to favor the survivorship of forbs. Colony numbers were found to decrease significantly as grass coverage decreased and forb species became dominant.
