Metapone tricolor McAreavey, 1949

Taylor, Robert W. & Alpert, Gary D., 2016, The myrmicine ant genus Metapone Forel (Hymenoptera: Formicidae): a global taxonomic review with descriptions of twelve new species, Zootaxa 4105 (6), pp. 501-545 : 539-540

25. Metapone tricolor McAreavey, 1949

( Figs 141–145 )

M. tricolor McAreavey, 1949: 4 , Figs 17–19 —Gyne; Type locality: Nyngan, New South Wales.

Distribution, material examined. AUSTRALIA: NEW SOUTH WALES: Nyngan (31°34’S, 147°12’] (J. Armstrong, 9, 9, 47) holotype alate gyne (ANIC). SOUTH AUSTRALIA: Strathalbyn, 35°16’S, 138°54’E, in water trough (R.D. Robinson, 25, 0 1, 87) alate gyne (SAMA). Kangaroo Island, eastern end (J. O. Schmidt, 1 Jan 1999) alate gyne (ANIC). Also provisionally identified below from far northeast QUEENSLAND.

Evidently widespread in south-eastern (or eastern) Australia, though known only from the specimens discussed here.

Provenance of the Kangaroo Island alate is uncertain. It was collected alive in late afternoon inside a tour bus which had arrived from its Adelaide base that morning by road and ferry and had then travelled widely on the Island (J. O. Schmidt, pers com.). The specimen could have entered the bus between Adelaide and Cape Jervis, but Kangaroo Island seems more likely.

Gyne diagnosis. General features as described by McAreavey (1949) and in the key and figures presented here. 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. 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 M. mathinnae worker holotype has HW 0.84, CI 78, and the type series M. tecklini gynes HW 0.83–0.92, CI 75–77.

Dimensions: (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.

Provisionally determined material: Despite the far-distant location in north east Queensland we relate the following provisionally identified specimen to M. tricolor : N.E. QUEENSLAND: 2km N of Rokeby (13°39’S 142°.40’E] flight intercept trap (15 Feb–18 March, 1994, P.Z & M.S.) alate gyne ( ANIC). It matches the diagnosis above and its indices are similar to the other specimens reviewed, but it is somewhat smaller. Dimensions (with appended percentage comparisons with the M. tricolor holotype): TL: ca 5.9; HL: 1.04 (79%); HW: 0.70 (78%); CI: 67; CpL: 0.37 (90%); CpI: 35; MSL: 1.75 (75%); ScW: 0.60 (76%); PetL: 0.45 (71%); PetW: 0.38 (84%); PetH: 0.59 (72%); PpetL: 0.43 (77%); PpetW: 0.49 (78%); PpetH: 0.57 (80%); GW: 0.70 (76) (Average difference 78%). Note especially the CI value.

All specimens discussed here, including the Rokeby individual, 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.

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, maps 41, 45, 170).

Figures

FIGURES 141 – 145. M. tricolor, holotype gyne, HW 0.89, ScW 0.79, MSL 2.33.

FIGURES 16 – 20. Metapone greeni, syntype worker, HW 1.01, PMW 0.82, MSL 1.56; FIGURES 21 – 23 gyne (M. johni syntype), HW 1.74, PMW 1.02, MSL 2.90.