Melobasis dividua, Levey, 2012

Levey, Brian, 2012, 3464, Zootaxa 3464, pp. 1-107 : 34-35

M. dividua sp. n.

( Figs. 23, 24, 104, 105, 167)

Type locality: W. Australia, Wurarga , Marloo sheep station (28°24'S 116°29'E) .

Type specimens examined. Holotype ♂ ( ANIC), Marloo Stn. Wurarga, W.A. 1931–1941 A. Goerling / HOLOTYPE Melobasis dividua sp. n. B. Levey det.; 13 Paratypes as follows. Western Australia: 1♂, 10♀ ( ANIC, BMNH, WAMA) same data as Holotype; 1♀ ( IRSNB) Wurarga , 27.1.1938, C. Deuquet; Queensland: 1♀ ( IRSNB) Mackay Dec. Ex. coll. Deuquet (undoubtedly wrongly labelled) .

Diagnosis. General diagnosis: length 10.1–12.5 mm.; head and pronotum dark greenish-bronze with reddishpurple or violet reflections; elytra brownish-copper with the following blue or violet markings: a sutural vitta in the basal quarter; a humeral vitta of about the same length, which extends narrowly along the basal margin to the epipleura which is similarly coloured for its basal quarter; rarely the humeral vitta is joined to the sutural vitta along the basal margin; a pair of median maculae which are sometimes narrowly joined to form a sinuate transverse fascia; an elongate roughly obovate pre-apical macula; underside brownish-bronze sometimes with reddish-purple reflections; lateral parts of underside moderately densely clothed with fairly long silvery pubescence.

Head: upper third of vertex moderately densely punctured with small ovate punctures; remainder of head very densely punctured with ovate punctures which largely coalesce to form short linear series orientated dorsoventrally on the lower half of the vertex and the frontoclypeus; moderately densely clothed with moderately long silvery pubescence; unpunctured areas weakly to moderately strongly microreticulate; clypeal excision fairly deep, U-shaped, with an unpunctured weakly to strongly microreticulate border; clypeal peaks slightly obtusely angled; vertex flat, about two-thirds width of head across eyes when viewed from above; eyes weakly convex.

Antenna: serrate from segment 4–10, the segments becoming progressively smaller and slightly less elongate, the expanded part of each segment more or less quadrate in ♂, that of segment 4 and sometimes 5 more or less triangular in ♀, the rest more or less quadrate.

Pronotum: 1.52–1.73 times as wide at base as long in midline; anterior margin weakly bisinuate, with a broad often strongly truncated median lobe; posterior margin bisinuate; widest behind, at or in front of mid-length; lateral margins weakly rectilinearly diverging from the posterior angles to widest point, sometimes slightly sinuate near posterior angles, thence weakly to moderately strongly curvilinearly converging to the anterior angles; as wide as or notably narrower at base than elytra at base; lateral carina almost straight or slightly sinuate, about half to twothirds complete; punctation moderately dense in central fifth, consisting of small round punctures, which become progressively larger and denser towards the lateral margin; without or with a narrow almost complete unpunctured midline; shiny to weakly microreticulate; moderately densely clothed with fairly long silvery pubescence in lateral half.

Scutellum: variable in shape, almost round, ovate to quadrate, about one-eleventh to one-twelfth width of elytra at base.

Elytra: 2.25–2.39 times as long as wide at base; basal margin moderately strongly bisinuate to biarcuate; parallel sided or very slightly widening from base over the humeral callosities, thence almost parallel sided to the mid-length, before narrowing to the narrow or broadly rounded apices; lateral margins from just beyond mid-length and apices with fairly coarse acute serrations, those at the apices being slightly smaller; sutural margin slightly raised in apical half; rather uniformly punctured, but with traces of one two costate intervals in the inner half; internal of the first costate interval, sparsely to moderately densely punctured with very small round punctures; external to the first costate interval the punctures become larger and dense, to very dense near the lateral margin, where they become ovate and form short transverse series; moderately strongly microreticulate.

Proepisternum: very densely punctured with moderately large, shallow, lunate punctures, partly obscured by dense long silvery pubescence.

Prosternum: with a narrow bead at the anterior margin, the anterior margin at almost the same level as the area behind; prosternal process strongly widening distally, sparsely punctured with small punctures, with a line of slightly larger punctures near the lateral margin, which are sometimes partly coalescent near the base; glabrous.

Mesoepisternum: densely to very densely punctured, with moderately large, shallow, mostly semi lunate punctures; partly obscured by long silvery pubescence.

Apical sternite: with the lunate punctures coalescent, their rims forming ridges more or less parallel to the lateral margin over most of the surface, but turned in towards the midline distally; excision fairly deep, much wider than deep in ♂ ( Fig. 23), as wide or slightly wider than deep in the ♀ ( Fig. 24); distal margin of the flange straight, the spines slightly developed, shorter than the depth of the flange.

Tarsal claws: slightly widened at base, but without a basal tooth.

Aedeagus ( Fig. 167).

Ovipositor: short, slightly longer than wide.

Comments. This species is unlikely to be confused with any other. The overall shape and elytral markings are most similar to M. brittoni sp. n., however in that species the apical sternite does not have lunate punctures forming grooves that turn in towards the midline distally, and the aedeagus is different.

Etymology. The name comes from the division of the median fascia of the elytra into two maculae in many specimens.

Bionomics. Adults collected in January. Larval hosts unknown.