Melobasis powelli, Levey, 2012

Levey, Brian, 2012, 3464, Zootaxa 3464, pp. 1-107 : 48-50

M. powelli sp. n.

(Figs. 109, 175, 204)

Type locality: Western Australia, 33–35km N. of Paynes Find .

Type specimens examined. Holotype ♂ ( WAMA), 33–35km N. of Paynes Find, W.A. 5 Sep. 2006, T.M. Hanlon & M. Powell, on spikey leaf Acacia / HOLOTYPE ♂ Melobasis powelli sp. n. B. Levey 2010. Paratypes as follows: Western Australia : 1♂, 3♀, ( NMWC, TMSHC), same data as Holotype ; 1♂, ( MPC), 35 km N. of Paynes Find W.A. September 4 2006, M. Powell & M. Hanlon, Acacia sp. leaves ; 2♂, ( MPC), 35 km N. of Paynes Find W.A. 10 Sep. 2000, M. Powell, on flowering Acacia ; 1♀, ( MPC), 2 km S. of Paynes Find W.A. September 11 2006, M. Powell, Acacia sp. leaves .

Diagnosis. General diagnosis: length 10.6–13.9 mm; head: ♂ upper third of vertex dull reddish-violet or steelblue, remainder of head dull blue-green; ♀ upper third of vertex dull blue-green, remainder of head greenishbronze with a variable dull reddish-violet reflection; pronotum in ♂ blackish-bronze with a variable dull reddishviolet or steel-blue reflection in lateral half, central half blue-black with a variably developed greenish-blue central line, in ♀ greenish- or brownish-bronze with a variably developed coppery central line; elytra bluish-violet, with the following golden or coppery markings: a sutural vitta in the basal fifth to quarter; a slightly shorter oblique humeral vitta internal to the humeral callosity, which extends laterally along the basal margin and along the lateral margin for a short distance, and is continued along the epipleura to the level of the first sternite; a slightly sinuate transverse median fascia which extends from the outer edge of the substural depression, almost to the lateral margin; a roughly obovate to slightly transverse pre-apical macula; underside greenish- or brownish-bronze; lateral parts of underside moderately densely clothed with moderately long silvery pubescence.

Head: very densely to contiguously punctured with small round and elliptical punctures which sometimes coalesce to form linear series orientated dorso-ventrally on the lower half of the vertex and the frontoclypeus; densely clothed with fairly long silvery pubescence; unpunctured areas shiny to strongly microreticulate; clypeal excision moderately deep, U-shaped, with an unpunctured weakly to strongly microreticulate border which is sometimes only developed at centre; clypeal peaks acute; vertex flat, three-fifths the width of head across eyes when viewed from above; eyes moderately strongly to strongly convex.

Antenna: serrate from segment 4–10, the segments becoming progressively smaller and slightly less elongate, in ♂ the expanded part of the segments is quadrate, in ♀ the expanded part of segments 4 and 5 are more or less triangular, segments 6–10 subquadrate.

Pronotum: 1.56–1.73 times as wide at base as long in midline; anterior margin bisinuate, with a shallowly produced broad median lobe, which is sometimes scarcely produced and then the margin is almost straight at the centre; anterior beaded margin narrow, but well defined; posterior margin bisinuate; widest at or slightly in front of the mid-length; lateral margins almost parallel for a very short distance in front of posterior angles thence divergent to widest point, or divergent from the posterior angles to widest point, thence strongly curvilinearly convergent from widest point to the anterior angles; slightly narrower at base than elytra at base; lateral carina slightly sinuate, about two-thirds to three-quarters complete; punctation sparse to moderately dense in central third, consisting of small round punctures, which become progressively larger and denser towards the lateral margin; with a well developed unpunctured midline, and sometimes a small transversely ovate unpunctured area on either side of the midline in the anterior third; shiny or with weak reticulate microsculpture; moderately densely clothed with moderately long silvery pubescence which is confined to the lateral half of the pronotum.

Scutellum: oblong to quadrate; shiny or weakly microsculptured; about one-fourteenth width of elytra at base.

Elytra: 2.24– 2.46 times as long as wide at the base; basal margin strongly bisinuate; slightly widening from base over the humeral callosities, thence almost parallel sided to slightly beyond the mid-length, before narrowing to the rounded apices; lateral margins from somewhat beyond mid-length and apices with strong acute serrations; sutural margin strongly raised in apical half; each elytron with a fairly well developed costa next to the subsutural depression, with indications of a slightly less well defined costa lateral to the first costa; subsutural depression sparsely punctured with very small round punctures; punctation adjacent to the costae partly longitudinally seriate; punctation external to the second costa becoming dense, the punctures larger and more ovate, forming short transverse series near the lateral margin; moderately strongly microreticulate

Proepisternum: very densely or contiguously punctured with moderately large, shallow round and ovate punctures, partly obscured by moderately long silvery pubescence.

Prosternum: with a narrow bead at the anterior margin, slightly lower than the area behind; prosternal process slightly widening behind the fore coxae, sparsely to moderately densely punctured with small round punctures, with a groove formed from coalescent punctures near the lateral margin; glabrous, or with sparse setae near the lateral margin.

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

Apical sternite ( Fig. 204): with lunate punctures near the lateral margin contiguous, but not forming grooves parallel to the lateral margin; excision about two times as wide as deep in ♂, two to three times as wide as deep in ♀; the lateral spines weakly developed, shorter than the depth of the flange; distal margin of flange straight

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

Aedeagus ( Fig. 175): parameres almost parallel sided.

Ovipositor: short, wider than long.

Comments: This species is very similar in colour, elytral markings and general appearance to M. janae sp. n. The more parallel sided parameres of the aedeagus, and the more transverse pronotal shape will distinguish this species from M. janae . Other differences are the wider apical excision of the last sternite of the ♀; the more strongly developed costae on the elytra, and the more strongly bisinuate basal margin of the elytra.

Etymology. This species is named after Michael Powell in recognition of his fieldcraft in collecting this and many other species of Melobasis .

Bionomics. Adults have been collected in early September on flowering Acacia (Fabaceae) . Larval hosts unknown.