Solenopsis undescribed
Classification
| Family: | Formicidae |
| Subfamily: | Myrmicinae |
| Tribe: | |
| Genus: | Solenopsis |
| Species: | undescribed |
Common name(s)
The common name " Thief ants" is used for members of the sub-genus (Diplorhoptrum) native to Australia (Andersen 2002): known to steal food from nests of other ants (Shattuck 1999).
Synonyms ( )
None known. Thought to be an undescribed Australian species.
Origin
World wide there are 266 known species and subspecies of Solenopsis, with an additional 8 species being known from fossils.
In Australia cryptic Solenopsis species are scattered throughout most coastal areas with the exception of western Western Australia, and with a limited number of collections from inland areas (WWW4). They are more common in cool, wet areas and are one of the most common ants in Tasmania in terms of number of nests. They are most abundant in dry and wet sclerophyll with fewer records from rainforests and mallee.
The earliest record in this country, a single queen, was found in a gypsy moth surveillance trap in St Helliers, Auckland in April 2002. Pitfall trapping and litter extractions in the surrounding area in 2003 revealed 10 workers. A queen has also been collected from a swimming pool in Royal Oak, Auckland in 2004.
Distribution (see map)
To date this species has been reported only from Auckland.
General Description
Identification
The antennae are 10 segmented (including the scape) and have a 2-segment (?) club. The front margin of the clypeus just above the mandibles has a single central elongate hair or seta. The rear face of the propodeum is rounded or with at most low, rounded ridges or protuberances, but never with teeth, spines or thin flanges.
Diagnostic features of the worker
Yellowish brown (very light brown). Weakly dimorphic, with minors 1.5 mm and majors about 2 mm in length, but without strong morphological differences. The small size of the workers of this species, their cryptic nature (absence of foraging trails), and lack of aggression, distinguish this species from the pest species of Solenopsis (e.g., S. invicta and S. geminata)
Biology
These small, cryptic ants nest either in open soil or under rocks (WWW4). When in open soil they sometimes have a mound of loose dirt around the nest entrance. They are also on occasion associated with the nests of other ants and termites. In some cases, 3 or 4 Solenopsis nests have been found in a single Myrmecia nest. When nesting with other ants or termites, they act as thief ants, raiding the hosts' nest for food. Although relatively uncommon in most areas, they can be locally abundant, foraging in leaf litter or on the ground.
Pest Status
Impacts not known, but considered unlikely to be a pest.
Compiled by Richard Harris with assistance from Disna Gunawardana
