Thievery in rainforest fungus-growing ants: interspecific assault on culturing material at nest entrance
Cleptobiosis in social insects refers to a relationship in which members of a species rob food resources, or other valuable items, from members of the same or a different species. Here, we report and document in field videos the first case of cleptobiosis in fungus-growing ants (Atta group) from a coastal, Brazilian Atlantic rainforest. Workers of Mycetarotes parallelus roam near the nest and foraging paths of Mycetophylax morschi and attack loaded returning foragers of M. morschi, from which they rob cultivating material for the fungus garden. Typically, a robbing Mycetarotes stops a loaded returning Mycetophylax, vigorously pulls away the fecal item from the forager’s mandibles, and brings the robbed item to its nearby nest. In our observations, all robbed items consisted of arthropod feces, the most common culturing material used by M. parallelus. Robbing behavior is considered a form of interference action to obtain essential resources needed by ant colonies to cultivate the symbiont fungus. Cleptobiosis between fungus-growing ants may increase colony contamination, affect foraging and intracolonial behavior, as well as associated microbiota, with possible effects on the symbiont fungus. The long-term effects of this unusual behavior, and associated costs and benefits for the species involved, clearly deserve further investigation.
KeywordsAnt behavior Fungus-growing ants Interference competition Theft Atlantic rainforest
We thank Edward O. Wilson, Bert Hölldobler, Rainer Wirth and Rodrigo Feitosa for feedback on the manuscript, and Luisa Mota for the drawing. MR and GM were funded by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior; PO was supported by the São Paulo Research Foundation (#2014/23141-1, 2017/16645-1) and the Brazilian Research Council (#306115/2013-1, 302219/2017-0). Rodrigo Feitosa identified the ants, and the Parque Estadual da Serra do Mar provided logistic support during field work. This study is part of the PhD dissertation of MR at the Programa de Pós-Graduação em Ecologia of the Universidade Estadual de Campinas.
Worker of Mycetophylax morschi returning to its nest with a feces item and Mycetarotes parallelus patrolling the nest vicinity of M. morschi. (MOV 19348 KB)
Worker of Mycetarotes parallelus intercepts a loaded Mycetophylax morschi, which returns to the nest with a feces item. Mycetarotes parallelus robs the item and takes it to its nearby nest. (MOV 37335 KB)
- Hölldobler B, Wilson EO (2011) The leafcutter ants: civilization by instinct. W.W Norton & Company, New York, pp 157Google Scholar
- Khadempour L, Burnum-Johnson KE, Baker ES, Nicora CD, Webb-Robertson BM, White RA, Monroe ME, Huang EL, Smith RD, Currie CR (2016) The fungal cultivar of leaf-cutter ants produces specific enzymes in response to different plant substrates. Mol Ecol 25:5795–5805CrossRefPubMedPubMedCentralGoogle Scholar
- Klingenberg C, Brandão CRF (2009) Revision of the fungus-growing ant genera Mycetophylax Emery and Paramycetophylax Kusnezov rev. stat., and description of Kalathomyrmex n. gen. (Formicidae: Myrmicinae: Attini). Zootaxa 2052:1–31Google Scholar