Orectognathus antennatus Fr. Smith 1853

Compiled by Warwick Don & Richard Harris

Biostatus: Introduced

Classification

Family:	Formicidae
Subfamily:	Myrmicinae
Tribe:	Dacetonini
Genus:	Orectognathus
Species:	antennatus

Common name(s)

Goblin ants (Andersen 2002)

Synonyms (WWW5)

Orectognathus antennatus septentrionalis Forel

Origin

There are 29 known species of Orectognathus, the majority of which occur in Australia (Shattuck 1999). One Australian species, Orectognathus antennatus is established in New Zealand. It is suspected to have entered the country with human assistance (Brown 1953). The earliest record appears to be a queen collected at Hikurangi, Northland, in 1927 (there is also an undated specimen from Drury ex Broun in the Canterbury Museum that probably predates this).

Distribution

This species is prevalent in Northland, Waitakere Ranges and has been recorded in the Coromandel and East Cap.

General Description

Identification

The antennae are 5-segmented, with the third segment from the tip elongate and much longer than the other segments of the funiculus. The mandibles are long and narrow with three teeth at their tips, of which the ventral pair are conjoined to form a short fork.

Diagnostic features of the worker

Length about 3.5 mm; propodeum armed with a pair of slender spines; colour of body yellowish rusty red-brown.

[Orectognathus antennatus] head. Image: April Nobile (Specimen code: CASENT0172360). www.antweb.org Image — Orectognathus antennatus head. Image: April Nobile (Specimen code: CASENT0172360). www.antweb.org

Orectognathus antennatus profile. Image: April Nobile (Specimen code: CASENT0172360). www.antweb.org

[Orectognathus antennatus] dorsal view. Image: April Nobile (Specimen code: CASENT0172360). www.antweb.org Image — Orectognathus antennatus dorsal view. Image: April Nobile (Specimen code: CASENT0172360). www.antweb.org

Biology

This species forms small colonies in forests, usually of less than 60 workers and at most 3 dealate queens. Nest sites include in soil under stones and in rotten logs. Shattuck (1999) notes the workers move slowly and forage primarily at night or on dull, overcast days, and that when disturbed they lie motionless to avoid detection. Their mandibles form snap-traps used to capture collembolans and other small arthropods, and are used in defence. Workers are mainly sampled in litter but queens have been collected from Malaise and light traps.

Pest Status

Rarely encountered and mostly sampled in forest. Role in native systems unknown but not considered a pest.