Comparative morpho-physiology of the metapleural glands of two Atta leaf-cutting ant queens nesting in clayish and organic soils

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Respiratory regulation in workers of the leaf cutting ant Atta sexdens rubropilosa Forel, 1908

1. Respiratory rates of workers of the leaf cutting ant Atta sexdens rubropilosa were measured at different oxygen pressures, at 25°C. 2. In experiments where different ants were used at each of the oxygen pressures, respiration was regulated down to 70.8 mmHg. 3. When the same ants were submitted in sequence to declining pO2, the 'oxygen dependence indexes' (Tang P.S. (1933) Quart. Rev. Biol. 8, 260-274) also suggested a good regulatory capacity. 4. The results are discussed in terms of the variation of the partial pressures of O2 and CO2 that the ants probably encounter when wandering to and from the nest to forage, and when performing their heavy tasks (leaf transport, offspring and fungus care). 5. CO2 rise and O2 fall, from ants' respiration inside the ant hill, may act as the factors that, in a reflex way, keep the spiracles open and increase ventilation and the frequency of CO2 emission to keep the oxygen supply adequate to face the energetic demand of the routine level of activity of the workers, when passing from normoxia (air) to hypoxia (in nest galleries).

Multivariate morphometrics and allometry and allometry in a polymorphic ant

In this paper we describe how morphological castes can be distinguished using multivariate statistical methods combined with jackknife estimators of the allometric coefficients. Data from the polymorphic ant, Camponotus rufipes, produced two distinct patterns of allometric variation, and thus two morphological castes. Morphometric analysis distinguished different allometric patterns within the two castes, with overall variability being greater in the major workers. Caste-specific scaling variabilities were associated with the relative importance of first principal component. The static multivariate allometric coefficients for each of 10 measured characters were different between castes, but their relative magnitudes within castes were similar. Multivariate statistical analysis of worker polymorphism in ants is a more complete descriptor of shape variation than, and provides statistical and conceptual advantages over, the standard bivariate techniques commonly used.

Unraveling Trichoderma species in attine ant environment: description of three new taxa

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)