Ant nests found in mature pods of Cassia fistula L. and the extended phenotype of herbivores as house to opportunistic twig dwellers

Ants can present specialized or opportunistic nesting habits; the latter not being restricted to a single or a narrow set of host species in an ecological interaction. Herein we report ant colonies belonging to seven species and four genera inside ripe pods of Cassia fistula L. (Fabaceae) with signs of previous occupation by herbivores. Among the species found nesting in pods previously excavated by phytophagous insects are Cephalotes targionii (Emery, 1894); Cephalotes eduarduli (Forel, 1912); Crematogaster aff. victima Smith, 1858 and Crematogaster sp. (Myrmicinae); Myrmelachista nodigera Mayr, 1887 (Hymenoptera: Formicidae: Formicinae); Pseudomyrmex gracilis (Fabricius, 1804) (Hymenoptera: Formicidae: Pseudomyrmecinae) and Tapinoma sp. (Hymenoptera: Formicidae: Dolichoderinae), all of which showed opportunistic behavior by using pods previously hollowed and holed by phytophagous insects. This is the first record of Cephalotes Latreille, 1802 ants nesting in structures other than trunks and branches.