Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Pheidole
Species: P. rugosula
Binomial name: Pheidole rugosula
Synonyms: Pheidole variabilis, Pheidole variabilis rugosula

Pheidole rugosula is a species of ant from Australia. It is in the genus: Pheidole of which there are four species in New Zealand
Pheidole rugosula is the most common of the four Pheidole species established here. It has been collected at a number of sites in Northland, is present in Waikato, Bay of Plenty, Taranaki, and Hawkes Bay, and has been collected as far south as Nelson and Christchurch.
Pheidole rugosula is a small, brownish yellow, short-limbed species with moderate head. The workers of Pheidole rugosula are dimorphic (major and minor workers). It is a small, brownish yellow, short-limbed species with moderate head. Their antennae are 12-segmented with usually a 3-segmented club. A major worker’s body is a reddish brown to nearly black and it has a length of 3 mm. Minor workers are smaller at 1-2 mm in length

They can be abundant in urban areas causing a nuisance. 
They have been observed capturing small insects, gathering seeds, food waste, attacking mantid oothecae and removing pet food. They are often found associated with rotting fruit. They will forage arboreally.

Major workers 3mm and Minor workers of 1 mm moving larvae.
1-Pheidole rugosula.jpg

Thanks to Wikipedia for text and information: