Pachycondyla castanea (Mayr 1865)
Synonyms (Valentine & Walker 1991 )
Ponera castanea Mayr, Euponera (Mesoponera) castanea var. striata Stitz, Euponera (Mesponera) castanea (Mayr), Euponera castanea (Mayr), Tonera castanea (Mayr), Ponera (Mesoponera) castanea (Mayr), Mesoponera castanea (Mayr)
According to Shattuck (1999) there are 277 known species and subspecies of Pachycondyla spread throughout the world. He lists 26 Australian species and subspecies. New Zealand has two endemic species, P. castanea and P. castaneicolor. Evidence points to a derivation of castanea from castaneicolor (R.W. Taylor pers. comm.). Those species of the genus inhabiting the Australian, Melanesian and Indo-Malayan regions appear to be closely related.
Distribution (see map)
P. castanea appears to be limited to the North Island and its offshore islands, but establishment on the South Island (particularly in the north) cannot be ruled out.
In the genus Pachycondyla, the mandibles are triangular with numerous small teeth along the inner margins; the mandibles touch the front of the clypeus when closed; the single node of the petiole has distinct front, top and rear faces; each tibia of the hind legs has two spurs, one large and comb-like and one small and simple.
Diagnostic features of the worker
Length 4.9–6.1 mm; antennae 12-segmented; eyes with about 30 ommatidia; mandibles long with about 10 teeth; metanotal groove deeply impressed; colour of head, body reddish to dark brown, antennae, legs yellowish-brown.
P. castanea has wingless and worker-like (ergatoid) queens, whereas P. castaneicolor has winged (alate) queens (Wilson & Taylor 1967). P. castanea seems to prefer nesting in shady native forests. Both species exploit the same nest sites — in soil under stones or in rotting logs. Highly predatory, they use an effective sting to immobilise prey.
Commonly sampled in pitfall traps, litter and on sweet baits.
Pachycondyla is commonly encountered in gardens, they have an effective sting and have been reported stinging people when the nests are disturbed.
Compiled by Warwick Don & Richard Harris