Melobasis latecostata, Levey, 2018

Levey, Brian, 2018, A revision of the Australian species of the genus Melobasis Laporte & Gory 1837 (Coleoptera: Buprestidae), Part 2 (Revision of the nervosa species group), Zootaxa 4528 (1), pp. 1-79 : 31-32

M. latecostata sp. n.

(Figs 18, 69–70, 120–121, 158)

Type locality: Western Australia, Geraldton .

Type specimens examined. Holotype ♂ ( NMVA), Geraldton W. Australia, J. Clark / F.E. Wilson Collection / M. costifera Thoms. Id. by H.J. Carter / HOLOTYPE Melobasis latecostata sp. n. B. Levey 2012. Paratypes as follows: 2 ♀ ( ANIC, NMVA) Geraldton, W. Australia, J. Clark ; 1 ♂, 1 ♀ ( WADA) no further data ; 1♀ ( WADA) Peppermint Grove, Capel, W.A. 26.12.40 . D.N.F.; 3 ♂, 1 ♀ ( BLC, IRSNB) Tammin W. A., H.W. Brown, ex Coll C. Deuquet .; 2 ♂, 3 ♀ ( IRSNB) Eradu, J. Clark, ex Coll C. Deuquet [some labelled with locality as Bralu and Bradu which must be an incorrect interpretation of the original written locality Eradu] ; 4 ♂ ( TMSHC) Busselton .

Other specimens examined. W. Australia: 1♀ (ANIC) Peppermint Grove Beach, W.A. 29 Oct. 1977, A. Atkins.

Diagnosis. General diagnosis: length 12.5–15.9 mm; entirely yellow to brownish bronze, except for the head in ♂ which is reddish copper; underside laterally very densely clothed with long silvery pubescence.

Head (Fig. 158): lower half of vertex and frontoclypeus contiguously, uniformly, punctate with small strong round punctures in ♂, in ♀ punctation less dense, the punctures slightly larger, less uniform, with obvious shiny impunctate areas between the punctures; densely clothed with long silvery pubescence; clypeal excision shallow V- or U-shaped; impunctate clypeal border absent or only present at sides; clypeal peaks right angled or obtuse angled, without a well defined clypeal angle; vertex flat, slightly more than half width of head across eyes when viewed from above; eyes very strongly convex in ♂, slightly less convex in ♀.

Antenna: slightly sexually dimorphic; ♂ triangularly serrate from segment 4–10, the segments subequal, about twice as long as wide; ♀ weakly triangularly serrate from segment 4–10, the segments somewhat shorter than in ♂, becoming slightly progressively shorter; segment 3 subcylindrical, slightly widening distally, about 2–3 × as long as wide at its widest point.

Pronotum: 1.47–1.58 × as wide at base as long in midline; anterior margin strongly bisinuate, with a well developed, moderately broad, median lobe, with a narrow beaded margin which is absent at the centre of the median lobe; posterior margin very weakly biarcuate; widest just in front of mid-length; lateral margins very slightly divergent from basal angles to widest point (sometimes with a slight sinuation just anterior of the basal angles), before very weakly converging to apical angles; basal angles slightly acute or right angled; as wide or very slightly narrower at base than elytra at base; lateral carina slightly sinuate about half to three-quarters complete; punctation in central-quarter to central-third sparse, consisting of small, shallow, weak, round and pin-prick punctures; punctation in lateral two-thirds to three-quarters dense consisting of larger, stronger, round punctures which become slightly transversely elliptical near the lateral margin where they form transverse series; with an impunctate median line, broad in the anterior half, sometimes scarcely indicated in the posterior half; with an irregular shaped, slightly raised, less densely punctate area in the lateral quarter, at the apical third; moderately densely clothed, with moderately long silvery pubescence in lateral half, glabrous or more sparsely clothed with similar pubescence in central-half.

Scutellum: almost quadrate, about one-eighteenth to one-fifteenth width of elytra at base.

Elytra 2.27–2.43 × as long as wide at base; basal margin very weakly biangulate; slightly widening from the base over the humeral callosities, thence almost parallel sided, or slightly widening to a little beyond mid-length, before narrowing to the rounded or sub-acute apices; lateral margins in apical quarter and apices with small weak serrations; sutural margins slightly raised in apical third, becoming costate nearer the base, and widening in basal fifth to produce a slightly raised, elongate, almost triangular shaped area (sutural boss); each elytron with four approximately equidistant costae: 1st costa widest, extending from base almost to apex; 2 nd costa extending from base almost to apex, where it almost coalesces with the 1 st; 3 rd costa extending from the humeral callosity to apical third; 4 th costa very narrow and only slightly raised, extending from humeral callosity almost to apex; the costae, raised sutural margin, and sutural boss very sparsely punctate with very small, weak, and pin-prick punctures; subsutural depression densely punctate with small, round, or slightly transversely elliptical punctures; punctation of rest of elytra consisting of larger, transversely elliptical punctures, mostly coalescing to form transverse series; weakly microreticulate.

Hypomeron: contiguously punctate, with small round punctures, almost completely obscured by very dense, long, silvery pubescence.

Prosternum: with a broad bead at the anterior margin; the anterior margin at the same level as the area behind; prosternal process slightly widening distally, sparsely punctate with small, weak, round, and pin-prick punctures, glabrous.

Mesanepisternum: contiguously punctate with small, variably shaped, shallow punctures, almost completely obscured by very dense long silvery pubescence.

Central part of metaventrite, inner part of metacoxa, central part of abdominal ventrites glabrous, moderately densely punctate with small lunate punctures, lateral parts of these structures very densely to contiguously punctate, with small lunate punctures, very densely clothed with long silvery pubescence, which largely obscures the punctation.

Apical ventrite (Figs 120–121): lunate punctures coalescing to form grooves parallel to the lateral margin, largely obscured by the pubescence; excision in ♂ broad, W shaped, with the flange produced as a transversely oblong lobe at the centre; lateral spines well developed, parallel (Fig. 120); ♀ moderately broad, U-shaped, the flange slightly produced in the mid-line, the lateral spines well developed parallel (Fig. 121).

Fore tibia: ♂ slightly curved, with a large posteriorly facing tooth at apex, and a slightly developed setal brush on the anterior face at the apex; ♀ tooth absent and setal brush less developed.

Mid tibia: ♂ strongly curved, with a few teeth at the apex on the inner face; ♀ almost straight without teeth.

Aedeagus (Figs 69–70): parameres slightly constricted behind the apical setae bearing part; apical setae bearing part broad, lightly chitinised,with numerous small, slightly curved, spine-like setae, in addition to the usual long fine setae; median lobe with a truncated tip.

Ovipositor: not examined.

Comments. This species is most likely to be confused with M. angustecostata and M. planithorax . Externally the slightly stouter form, slightly broader 1st elytral costa, denser pubescence of the underside, and smaller weaker serrations of the lateral margins of the elytra in M. latecostata , being the most significant external features distinguishing it from those species. The form of the aedeagus will also easily distinguish this species from the above mentioned species.

Etymology. The name comes from the relatively wider 1 st elytral costae in comparison to that of M. angustecostata sp. n.

Bionomics. Adult collected in late December. Adult and larval hosts unknown.