Tetramorium bicarinatum (Nylander 1846)
Pennant ants (Andersen 2002) (Generic common name)
Synonyms (WWW5; Bolton 1977 )
Myrmica bicarinata Nylander, Myrmica cariniceps Guérin-Méneville, Myrmica kollari Mayr, Tetramorium kollari (Mayr), Myrmica modesta Smith, Myrmica reticulata Smith, Tetramorium cariniceps (Guérin-Méneville)
Tetramorium is a large genus, with 445 known species and subspecies worldwide (Shattuck 1999). Shattuck lists 24 described Australian species, the majority of which are endemic. New Zealand has two established introduced species: Tetramorium bicarinatum, of South-East Asian origin, and T. grassii . The earliest fully documented record of bicarinatum (known then as T. guineense ) in this country comprises a large sample extracted from several nests at Penrose, Auckland, in April 1959 (Taylor 1961).
Distribution (see map)
The few collection records indicate a distribution essentially restricted to Northland, Auckland City and Bay of Plenty. There is an isolated record from Taranaki, but the fact that it was collected from the Shell Oil site in New Plymouth may suggest an independent port entry rather than through dispersal from the north. Also collected from Raoul Is.
The antennae of the workers are 11 or 12-segmented, with a 3-segmented club. The lateral portions of the clypeus are raised into a sharp ridge in front of the antennal insertions. The propodeum is armed with a pair of spines above, and a pair of flanges below near the insertion of the petiole (waist). Usually sculptured over the head and mesosoma. The tip of the sting has a triangular to pennant-shaped extension projecting upward from the shaft (visible only when the sting is extended).
Diagnostic features of the worker
Length 3.4 to 4.5 mm; antennae 12-segmented; metanotal groove absent; propodeal spines strong and acute, moderately long; petiolar (front) lobe of waist roughly rectangular; sculpture on head, mesosoma and petiolar nodes; colour of head, mesosoma and waist varies from light yellow-brown to bright orange-yellow, gaster deep brown or blackish brown.
Little of its biology is known. Colonies are small to moderate in size. Nests are to be found in exposed soil or under stones, rotting logs [one nest was found under a rotting plank some 40 km east of Tauranga (AWD pers. obs.)], or in plant stems or under bark (Smith 1965). This species has been known to feed on a variety of foodstuffs in houses, but has not been recorded as doing so in this country. Honeydew is collected from sap-sucking insects and both dead and living prey are exploited.
Potential to be minor urban nuisance entering houses and nesting in gardens. Capable of stinging.
Compiled by Warwick Don & Richard Harris