Melobasis thoracica, Blackburn, 1887

Levey, Brian, 2012, 3464, Zootaxa 3464, pp. 1-107 : 16-17

M. thoracica Blackburn

( Figs. 29, 31, 32, 83, 84, 95, 158)

Melobasis thoracica Blackburn, 1887: 246 ; Kerremans 1903; Carter 1929: 286; Obenberger 1930: 435; Bellamy 2002: 165; 2008: 1335. Type locality: South Australia (Port Lincoln?). [In his original description Blackburn says he cannot recall the circumstances of its capture and gives the locality as South Australia. However in his notebook in BMNH he has written P.L. against the name which probably stands for Port Lincoln.]

Melobasis nitidiventris Kerremans 1898:122 ; 1903: 159; Carter 1923: 78; 1929: 285; Obenberger 1930: 433; Bellamy 2002: 158; 2008: 1327. Syn. n. Type locality: Australia.

Type specimens examined. M. thoracica Holotype ♂ ( BMNH) Holotype / Type/ 2207/ Blackburn Coll. 1910-236/ Melobasis thoracica, Blackb. / HOLOTYPE Melobasis thoracica Blackburn. B. Levey det.1990.

M. nitidiventris Kerremans Holotype ♀ ( BMNH) Holotype / Type/ Australie Starck/ Collection Chevrolat/ nitidiventris Kerr. Type/ M. nitidiventris Kerr. Australie / Kerremans 1903 -59.

Other specimens examined: Western Australia: Albany; Lancelin; 16mls. S. of Borden; Kalbarri; Lake Grace; Little Anchorage; mouth of Moore River; 9km W. of Hopetown (33.57S, 120.07E.); South Australia: Alligator Gorge National Park; Arkaroo Rock; Athelston; Belair National Park; Bunker Hill, Flinders Chase, Kangaroo Island; Kuitpos Forest. Victoria: Bendigo; Brisbane Ranges, between Bacchus Marsh and Meredith; Eltham; Emerald; Gippsland; Gisborne; Glen Innes; Hawell; Inglewood; Lakes Entrance; Little Desert; 4.3 mls S.E. of Longford; Melbourne; Nowa Nowa; 5mls N. of Nowa Nowa; 10 mls N.W. of Orbost; Ringwood; Sea Lake; South Morang; Taradale; Toolern Vale; Victor Harbour; Wallan; Wattle Glen.

New South Wales: Armidale; Blue Mountains; Boural; Cocoparra; Cullen Bullen; Falconbridge Ridge; French’s Forest; Gordon; Hill End; Hornsby; Jenolan Caves; Leura; Heathcote Rd., near Lucas Heights; 3 mls N. of Repton; Sandy Point, Sydney; National Park, Sydney; North Sydney; Wahroonga; Waterfall; Wedderburn; Mount White. A.C.T.: Black Mountain, Canberra. Queensland: Glen Aplin; Stanthorpe.

Specimens examined from AMSA, ANIC, ASC, BMNH, CLBC, DAS, FCNSWA, GBC, IRSNB, JTCA, MVMA, NMWC, SWCA, UQA, WAMA.

Diagnosis. General diagnosis: length 6.5–10.0 mm; head largely green or yellow-green in male, with upper part of vertex coppery; head largely dull reddish-violet to dull brownish-copper in female, with upper part of vertex sometimes brown-bronze; pronotum reddish-violet often with coppery reflections, sometimes bluish-green; elytra largely reddish-violet, however, centre sometimes bronze-green or blackish-brown or more rarely blackish-green (E. & S. Australia) or yellow-bronze to brown-bronze (S.W. Australia); underside bright reddish-violet with coppery reflections; glabrous except for very short, fine, very sparse setae on the lateral parts of the underside.

Head: densely punctured with small, shallow, round punctures, often becoming transversely coalescent on the clypeus; vertex sometimes with a poorly defined, large, shallow depression at the centre; glabrous or with sparse, short, very fine setae almost confined to the clypeus; weakly microsculptured; clypeus usually slightly depressed at centre; clypeal excision almost absent or very shallow, U-shaped, with a fairly broad, weakly microreticulate, unpunctured border; lateral margins of clypeus sometimes strongly turned in towards the midline distally, not forming acute angles with the clypeal excision; vertex flat, about half width of head across eyes when viewed from above; eyes moderately convex.

Pronotum: 1.58–1.71 times as wide at base as long in the midline; anterior margin moderately strongly bisinuate, with a well developed broad median lobe; posterior margin strongly biarcuate; widest at or slightly in front of the mid-length; lateral margins moderately strongly, slightly curvilinearly to almost rectilinearly diverging from posterior angles to widest point then strongly, curvilinearly converging to the anterior angles; slightly narrower at base than elytra at base; lateral carina almost straight, about half complete; punctation at centre consisting of very transverse punctures, forming slightly sinuate transverse series, which are weaker and lunate in the anterior third; laterally, densely punctured with large, shallow punctures, which become deeper and smaller near the lateral carina; moderately strongly microreticulate at centre; usually with a narrow, unpunctured median line in the posterior two-thirds.

Scutellum: quadrate or slightly elongate, the posterior margin rounded; about one-tenth width of elytra at base; moderately strongly microreticulate.

Elytra: basal margin strongly biarcuate to biangulate; slightly to moderately strongly widening over the humeral callosities, thence slightly rectilinearly widening to slightly beyond the mid-length, before narrowing to the moderately broad, subangulate apices; lateral margins and apices very weakly, obtusely serrate; sutural margin strongly raised for most of its length; inner half with traces of four very finely punctured striae, the second interstria usually slightly costate; laterally almost uniformly densely to very densely punctured with much larger and stronger punctures with a tendency to form transverse series; reticulate microsculpture weak on the inner half, becoming stronger on the densely punctured lateral parts.

Proepisternum: very densely punctured with moderately large very shallow elliptical punctures; pubescence very sparse, short and inconspicuous.

Prosternum: with a narrow bead at the anterior margin at about the same level as the area behind; prosternal process slightly widening posteriorly, sparsely to moderately densely punctured with small round punctures, with a line of slightly larger punctures parallel and close to the lateral margin; sparsely clothed with short pubescence.

Mesoepisternum: more or less densely punctured with small round and vermiform punctures.

Apical sternite ( Fig. 25): with well separated lunate punctures laterally; excision in ♂ and ♀ shallow, much wider than deep, the distal margin of the flange straight, the lateral spines short, slightly divergent, not longer than the depth of the flange.

Mid tibia: ♂ straight with small serrations on the ventral face, sometimes only obvious close to the apex; ♀ straight without serrations on the ventral face.

Tarsal claws: not abruptly widening or toothed at base.

Aedeagus ( Fig. 158): aedeagus strongly widening from the basal piece to its widest point; apex of median lobe produced, with the tip rounded

Ovipositor ( Fig. 156): about as long as wide.

Comments. In the field might be mistaken for some members of the obscurella species-group. The south west Australian form likely to be confused with the female of M. duplexicolor sp. n.

Bionomics. Adults collected between August and December (mainly September–November). Adults mainly recorded on Acacia spp. (Fabaceae) , with single records on Casuarina sp. (Casuarinaceae) , Cassia sp. (Fabaceae) , Genista monspessulana (L.) L.A.S. Johnson ( Fabaceae ), Grevillea sp. (Proteaceae) , Hakea sp. (Proteaceae) . Larval hosts unknown.