Turneria rosschinga

Turneria rosschinga is known from eastern New South Wales and Tasmania and is likely present in eastern Victoria although it is yet to be encountered there. It is the only species within the genus known to occur in cool temperate areas, the remaining species being found in more tropical areas, typically in rainforest habitats. It has been collected only four times, and each time only a single worker has been found. This makes it among the most infrequently encountered ants known from Australia. Three of the collections were from pitfall traps while one worker was found foraging on a Eucalyptus trunk among workers of Anonychomyrma.

Biologically, little is known about this species. Three of the four known collections were from pitfall traps, while the fourth was of a single worker foraging on a Eucalyptus trunk in an abandoned paddock. This individual was foraging together with Anonychomyrma workers and was initially confused with them as it is superficially very similar to typical Anonychomyrma workers. Whether there is a biological relationship between these species, or if they were simply foraging independently on the same tree, is unknown at this point.

Identification
Belonging to the genus Turneria but differing from all other known species in having the propodeum low and rounded and lacking the rounded protuberances found in other species. Additionally, this is the most hirsute species in the genus, with abundant long erect hairs present on the dorsal surfaces of the head and mesosoma.

This species lacks the characteristic protuberances on the propodeum found in other members of the genus, instead the propodeum is low, rounded and relatively elongate and similar to that found in typical dolichoderines. In fact the shape of the propodeum is nearly identical to that seen in Iridomyrmex mirabilis. However, it differs from that species in having the spiracle higher and protuberant while in I. mirabilis the spiracle is typical of Iridomyrmex in being lower on the propodeum and more or less flush with the surface. It seems likely that T. rosschinga represents a basal element within the genus, sharing a number of characters (abundant pilosity and low, rounded propodeum) with forms outside the genus which are not found in other species within the genus.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Nomenclature

 *  rosschinga. Turneria rosschinga Shattuck, 2011b: 127, figs. 5-10 (w.) AUSTRALIA.

Description
Worker. Head very slightly longer than wide (CI 95 - 99), anterior clypeal margin weakly concave medially; eyes elongate but less so than in other Turneria species; erect hairs absent from scapes and sides of head, abundant elsewhere, entire head capsule with abundant appressed pubescence; mandibles with nine teeth. Promesonotum forming a uniform arch, pro-mesonotal suture only slightly impressed; metanotal groove well developed, separated from propodeum by a short, nearly vertical face; propodeum relatively low, posterior face much shorter than dorsal face; propodeal spiracles just below propodeal angle and raised on low protuberances; erect hairs present on dorsal mesosomal surface, appressed pubescence abundant but less so on lateral surface of pronotum. Petiole included strongly anteriorly and with a rounded apex. Gaster with abundant pubescence and numerous erect hairs. Legs lacking erect hairs. Body reddish-black, antennae, mandibles and tarsi yellowish-red.

Measurements. Worker (n = 3, including holotype). CI 95-99, EI 29, EL 0.25-0.29, HL 0.89-1.04, HW 0.86-0.98, ML 1.17-1.44, MTL 0.67-0.77, SI 73-74, SL 0.64-0.72.

This species differs significantly from others in the genus both biogeographically and morphologically. It is placed in Turneria based on the configuration of the frontal carinae which are widely spaced and with their posterior extensions approaching the anteromedial margins of the eyes. This feature is shared with existing Turneria species but is never seen in other genera. Additionally, the mandibular teeth are uniform in size and spacing rather than being asymmetrical and irregular as found in the otherwise similar genus Iridomyrmex. These characters suggest that this is a slightly aberrant Turneria rather than a member of another dolichoderine genus.