Ecology and behaviour of the weaver ant Camponotus (Myrmobrachys) senex

Abstract

Weaver ants use silk produced by their larvae to build their nests. This behaviour is one of the more notable instances of social cooperation in animals; however, there are few studies of Brazilian species. This study investigated the ecology, natural history and behaviour of the weaver ant Camponotus (Myrmobrachys) senex in Brazil and showed that the weaver larvae have a fundamental function in nest building. The nests were always arboreal (one nest/plant), with a round form, beige in colour, and with leaves and shoots adhered to the silk nest. The average size was 34.24 cm and the average weight was 163.87 g; nests contained up to 50,000 individuals and several queens. Fusion and fission of colony parts were observed for C. senex. Worker ants were frequently observed feeding on honeydew, fruits and insects; and defended their territory. We suggest that C. senex larvae could be considered an effective caste, valuable in nest construction.

Keywords:

• behaviour
• cerrado
• Formicinae
• nest
• silk

Acknowledgements

We are grateful to the Pós-graduação em Ecologia e Conservação de Recursos Naturais – UFU, Fapemig and CNPq for financial support to J.C. Santos and K. Del-Claro and to E. Tizo-Pedroso and three anonymous referees for critical review of the manuscript.