Mayriella overbecki

This is one of the rarer species of Mayriella, being known from only five collections. These collections were from rainforest in north-eastern New South Wales, with nests being found in rotten logs.

Identification
This species can be separated from others in the genus by the combination of small, scattered pits on the mesosomal dorsum, weak sculpturing in the posterior sections of the antennal scrobes and the petiole with a relatively long posterior face and acute angle. (Shattuck and Barnett 2007)

Identification Keys including this Taxon

 * Key to Australian Leptomyrmex Species

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Biology
Species of Mayriella show strong preference for moist, forested areas. Most specimens have been collected from rainforest or wet sclerophyll woodlands with relatively few collections from dry sclerophyll or scrub habitats (and these are restricted to Australia). Nests are normally found in soil under stones or with a small mound of loose dirt at the entrance. They have also been found nesting in rotten logs and occasionally arboreally. The number of workers in nests averages between 50 and 100 and about one-half of the nest series containing queens contain more than one, suggesting that species are polygynous. Foraging workers are most commonly collected from litter samples. Nests appear to be locally abundant although patchily distributed on a larger scale. For example, in the Brindabella Ranges near Canberra, ACT, Mayriella ebbei is infrequently encountered and is known from only a few localities. However, near Baroomba Rocks (located on the eastern slope of the Brindabella Ranges) M. ebbei occurs commonly under rocks in an area covering several hundred square meters. This population appears limited to this small area as nests could not be found in areas with similar geography and vegetation located several kilometers away. However, observations are limited and additional data will be required to determine if these habits are widespread and/or occur in other species. Additionally, while Taylor (1961) made similar observations for Mayriella abstinens, these were based on the introduced population found in New Zealand and should be confirmed for naturally occurring populations of the genus. (Shattuck and Barnett 2007)

Nomenclature

 *  overbecki. Mayriella overbecki Viehmeyer, 1925a: 26 (w.q.) AUSTRALIA. Junior synonym of abstinens: Wheeler, W.M. 1935e: 151 (footnote). Revived from synonymy: Shattuck & Barnett, 2007: 446.

Worker
Shattuck and Barnett (2007) - Sculpturing in posterior section of antennal scrobe at most weakly developed and always indistinct; sculpturing on dorsal mesosoma consisting of small, widely spaced pits; propodeal spines relatively short and thick; dorsal surface of petiole in lateral profile uniformly convex, without distinct dorsal and posterior faces and forming a blunt angle with the anterior face; in dorsal view, postpetiole with the anterior and posterior regions approximately the same width (the region connecting them either flat or weakly convex); postpetiole and gaster lacking erect hairs dorsally.

Measurements. Worker (n = 7): CI 0.91-0.94; HL 0.51-0.57; HTL 0.30-0.35; HW 0.48- 0.53; ML 0.54-0.62; PW 0.33-0.37; SI 0.62-0.68; SL 0.30-0.35.