A review of the nesting habits and
socioecology of the ant genus Polyrhachis Fr. Smith
SIMON K.A. ROBSON1* & RUDOLF J. KOHOUT2
1 School of Marine & Tropical Biology, James Cook University
Queensland 4811, Australia,
2 Biodiversity Program, Queensland Museum, PO Box 3300, South
Brisbane Queensland 4101, Australia
Abstract: We provide a summary of the nesting and socioecological
habits of 197 species of Polyrhachis ants. Nesting
habits range from subterranean to terrestrial, lignicolous,
lithocolous and arboreal with varying levels of consistency
at the subgeneric level. Species are predominantly either
subterranean or terrestrial nesting within the subgenera Campomyrma,
Chariomyrma and Hagiomyrma; mainly arboreal
nesting within Aulacomyrma, Cyrtomyrma,
Hedomyrma, Hemioptica, Myrmatopa
and Myrmothrinax; lignicolous within Hedomyrma,
and variable within Myrma, Myrmhopla and
Polyrhachis. The majority of species within a particular
subgenus demonstrate a consistent nesting type but a few species
can be highly variable, demonstrating both subterranean and
arboreal habits. The inclusion of larval silk in the nests
is correlated almost entirely with arboreal nesting, but the
presence of spider silk in the nests of at least four species
suggests caution when inferring silk origin. Pupal cocoons
are present in all but Cyrtomyrma and Myrmatopa.
Polydomy and polygyny are known from a number of species and
may be more common in arboreal nesting species, but limited
data sets prevent definitive interpretations at this time.
Keywords: Polyrhachis, Formicidae, nesting ecology,
socioecology, mating systems
