Metapone tricolor

A south-eastern Australian species that is found in Eucalyptus woodland.

Identification
Taylor and Alpert (2016) - Distinguished from most other known Australian Metapone species by medium size, (HW 0.84–0.89), narrow, elongate head (CI 66–68), relatively light sculpturation, and the clypeal and subpetiolar structure.

Gynes of the larger Australian Metapone species have the collective HW range of 0.99–1.45. The Metapone mathinnae worker holotype has HW 0.84, CI 78, and the type series Metapone tecklini gynes HW 0.83–0.92, CI 75–77.

All specimens examined for this study, including an individual from Rokeby, have similar sculpturation with only slight variation in its intensity of expression: frons largely smooth and shining with irregularly-spaced very fine striae anteriorly from about the anterior level of the eyes, and a stronger incised median line reaching to the anterior ocellus. Antennal fossae and cephalic cheeks with more intense, close-spaced and regular striation. Mesosomal dorsum and sides very finely and somewhat thinly striate, much like the anterior frons, apart from the sparsely point-punctate propodeal dorsum. Sides of petiole similarly but less-strongly striate.

Distribution
Taylor and Alpert (2016) - Evidently widespread in south-eastern (or eastern) Australia.

Distribution based on Regional Taxon Lists
Australasian Region: Australia.

Biology
Taylor and Alpert (2016) - Possible termite associations: Acceptance of conspecificity among the above specimens presumes M. tricolor to be very widespread in dry Eucalyptus woodland. If it is an obligate associate of a single termite species that species must be present across that tricolor range. Possibilities are the subterranean species Coptotermes acinaciformis (Froggatt) or C. frenchi Hill (both Rhinotermitidae) or the probably less-likely Ephalotermes argutus (Hill) (Termitidae) (Watson & Abbey, 1993).

Nomenclature

 *  tricolor. Metapone tricolor McAreavey, 1949: 4, figs. 17-19 (q.) AUSTRALIA.

Queen
Taylor and Alpert (2016) - (holotype, Strathalbyn specimen, Kangaroo Island specimen): TL: ca 7.8, 6.7, 7.4; HL: 1.31, 1.27, 1.29; HW: 0.89, 0.84, 0.88; CI: 68, 66, 68; CpL: 0.41, 0.42, 0.43; CpI: 31, 33, 33; MSL: 2.33, 2.16, 2.29; ScW: 0.79, 0.75, 0.74; PetL: 0.63, 0.55, 0.58; PetW: 0.45, 0.47, 0.49; PetH: 0.82, 0.73, 0.78; PpetL: 0.56, 0.45, 048; PpetW: 0.63, 0.56, 0.61; PpetH: 0.71, 0.63, 0.66; GW: 0.97, 0.92, 96. Measurements of the Strathalbyn specimen apart from TL are separately all within 87–97% of those of the holotype (mean 92%), for the Kangaroo Island specimen 88–99% (mean 96%). The least consistent dimensions are those of the petiole and postpetiole, indicating differences in relative proportions.

General features as described by McAreavey (1949) and in the key and figures. Clypeus narrowed anteriorly, with slight anterolateral extensions, barely denticles. Subpetiolar process, relatively simple; subpetiolar lamella translucent, almost semicircular and nearly as long as the ventral edge; posterior subpetiolar surface approximately equilaterally-triangular, its outer edges minutely carinate.