Polygyny, oviposition, life cycle and longevity of the three subspecies of leaf-cutting ants, Acromyrmex subterraneus (Hymenoptera: Formicidae)

ABSTRACT

Research related to the comparative biology of phylogenetically close ant species has received little attention, although it is the basis for understanding the systematics of some sibling groups. The objective was to study the polygyny, oviposition, life cycle and longevity of the three subspecies of leaf-cutting ants. For that, we studied: oviposition rate – queens from three colonies were individually placed in plastic containers, and at 24-hour intervals, the laid eggs were quantified over a period of 96 hours; the workers’ life cycle – the development of immature ants was observed every 24 hours and, as a result, the duration of each stage of development was determined; the workers’ longevity – newly emerged adults were tagged and returned to the fungus chamber of their respective nests, and daily observations were made in each of the nest’s chamber. Laying rates were variable in the three queens studied, with a mean of total eggs laid of 271 for Acromyrmex subterraneus brunneus, 113 for Acromyrmex subterraneus subterraneus and 119 for Acromyrmex subterraneus molestans.The incubation period was 21.2 days in A. s. brunneus, 22.8 days in A. s. subterraneus and 20.4 days in A. s. molestans. The larval phase and pupal phase lasted on average 22.5 and 21.2 days in A. s. brunneus, 22.8 and 15.8 days in A. s. subterraneus and 17.2 and 14.2 days in A. s. molestans, respectively. Life cycle was different in the studied taxa, from 62 to 77 days in A. s. brunneus, from 59–68 days in A. s. subterraneus and from 51 to 55 days in A. s. molestans. The workers’ longevity varied between subspecies A. s. brunneus, A. s. subterraneus and A. s. molestans.

KEYWORDS:

• Acromyrmex subterraneus brunneus
• Acromyrmex subterraneus subterraneus
• Acromyrmex subterraneus molestans
• leaf-cutting ants
• oviposition
• life cycle
• workers’ longevity

Acknowledgements

We would like to thank the Coordination for Improvement of Higher Education Personnel (Coordenadoria de Aperfeiçoamento de Nível Superior) (CAPES) for the scholarship granted to the first author. L.C. Forti gratefully acknowledges the support from the National Council for Scientific and Technological Development (Conselho Nacional de Pesquisa e Tecnologia) (CNPq) (Grant No. 301167/2003-6).

Disclosure statement

No potential conflict of interest was reported by the authors.

Author contributions

Ana Paula P. Andrade and Luiz C. Forti conceived and designed the experiments; Ana Paula P. Andrade, Luiz C. Forti and Roberto S. Camargo performed the experiments; Roberto S. Camargo analysed the data; and Luiz C. Forti contributed with materials/analysis tools. Vânia Maria Ramos, Kátia Kaelly Andrade Sousa, Roberto S. Camargo, Ana Paula P. Andrade, Aline de Amorim Costa da Silva and Luiz C. Forti wrote the paper.