Melobasis rubromarginata, Saunders, 1876

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 : 39-40

M. rubromarginata Saunders

(Figs 34, 90–91, 141–142, 172, 177, 210–211)

Melobasis rubromarginata Saunders 1876:156 ; Kerremans 1885:137; Masters 1886:73; Kerremans 1892:105; 1903:160; Carter 1923:81; 1929:285; Obenberger 1930:432; Bellamy 2002:155; 2008:1325. Stat. rev. (not syn. of M. lathami (Laporte & Gory) . Type locality: N. W. Australia.

Melobasis bicolor Blackburn 1891:295 ; Kerremans 1903:159; Carter 1923:81; 1929:285; Obenberger 1930:432; Bellamy 2002:155; 2008:1325. Stat. rev. (not syn. of M. lathami (Laporte & Gory)) . Type locality: W. Australia, Kimberley.

Type specimens examined. Melobasis rubromarginata Saunders Holotype ♀ (BMNH) N W Aust./ M. rubromarginata ES/ HOLOTYPE Melobasis rubromarginata Saunders, B.Levey det. 1972. Melobasis bicolor Blackburn Holotype ♀ (MVMA) Kimberley, West Australia / Melobasis bicolor Blackb. / Type/ M. lathami C. & G. var. id. by H.J. Carter/ C. French’s Coll. 5.11.08 / Type/ Type of Melobasis bicolor Blkb. / T-8154 M. bicolor Blkb. / HOLOTYPE Melobasis bicolor Blackbn. B. Levey 1974 comp. with orig. desc. Holotype imaged at http:// collections.museumvictoria.com.au/search.php

Other specimens examined. Western Australia: Augusta; Bellvue; Beverley; Bullsbrook; Bunbury; Bushmead; Dandaragan; Darling Range, Lane Pool C.R.; Eneabba; Forrestfield; Fitzgerald River; Geraldton; Geraldton highway, 70 mile post; Goomalling, 6mls west; Greenmont; Moresby Range, Howatharra Road; Midland; Mount Barker; Murchison House; Murchison River; Narrogin; Pinjarra; Perth; Riverton, Bulls Creek; Wongong Gorge; Yanchep. Specimens in AMSA, ANIC, BCM, BLC, BMNH, MVMA, QMA, SAMA, SGCB, UQA, WADA, WAMA.

Diagnosis. General diagnosis: length 9.5–11.9 mm; upperside olive–green with extensive golden to coppery reflections, rarely upperside largely reddish copper (as in the holotype of M. bicolor ), with the elytral apices and lateral margins, with extensive reddish purple to reddish violet reflections, elytral costae usually darker than the ground colour of the elytra; underside golden green or blue green, medial parts and legs often with extensive reddish purple or coppery reflections, rarely the underside is entirely deep reddish violet; underside laterally sparsely clothed with short silvery pubescence.

Head (Fig. 172): ♂ contiguously punctate, with small round strong punctures, ♀ very densely to almost contiguously punctate, the punctures slightly weaker; moderately densely clothed with short silvery pubescence, which does not obscure the punctation; rims of the punctures microreticulate in ♂, shiny to weakly microreticulate in ♀; clypeal excision very shallowly excised, with a narrow, poorly defined, impunctate, shiny or microreticulate border; clypeal peaks right angled, without or with a slightly defined clypeal angle; vertex flat, half width of head across eyes when viewed from above; eyes very strongly convex.

Antenna: slightly sexually dimorphic; in ♂ segment 3, triangularly expanded, segments 4–11, with expansion almost quadrate; in ♀ segment 3 and 4 sub-triangularly expanded, 5 –10 sub-quadrate to almost quadrate; distal segments more elongate in ♂ than in ♀.

Pronotum: 1.35–1.53 × as wide at base as long in midline; anterior margin strongly bisinuate, with a moderately well developed, broad, median lobe; with a narrow but well defined beaded margin; posterior margin weakly biarcuate; widest at basal third, mid-length or apical third; lateral margins parallel sided for a short distance from basal angles before diverging to widest point, thence weakly converging to apical angles; basal angles acute; as wide as, or very slightly narrower at base than elytra at base; lateral carina almost straight, about two-thirds to three-quarters complete; punctation in central half dense, mostly consisting of small, transversely elliptical punctures, arranged in transverse sinuate rows, sometimes with traces of an impunctate median line, the punctures becoming much larger laterally; punctures in lateral half mostly round or ovate, very dense; with inconspicuous sparse short silvery pubescence close to the lateral margin, mainly confined to the apical third.

Scutellum: shield shaped, about one-sixteenth to one-fourteenth width of elytra at base.

Elytra 2.56–2.79 × as long as wide at base; basal margin very weakly bisinuate; slightly widening from the base over the humeral callosities, thence parallel sided, or slightly widening, to mid-length, before narrowing to the sub-acute apices; lateral margins in apical half, and apices, with moderately coarse acute serrations; sutural margins slightly raised in apical two-thirds; each elytron with three approximately equidistant costae; 1 st costa extending almost from base to apex; 2 nd costa extending from basal quarter, or sometimes from base, to apical sixth, sometimes almost fusing with 1 st costa at apical sixth; 3 rd costa extending from humeral callosity, often fusing with 2 nd costa at apical fifth; subsutural depression moderately densely punctate, with small round punctures; lateral to the first costa the punctures become transversely ovate to elliptical and slightly denser, lateral to the 3 rd costa becoming slightly larger; weakly microreticulate.

Hypomeron: very densely to contiguously punctate, with small, shallow, mostly ovate punctures, with sparse, short, 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 to moderately strongly widening distally, sparsely punctate, with small, weak, round and pin-prick punctures, glabrous.

Mesanepisternum (Fig. 177): shiny, with shallow round seate bearing punctures, mostly concentrated in the anterior half.

Central part of metaventrite, inner part of metacoxa, central part of abdominal ventrites glabrous, or sparsely pubescent, more sparsely and weakly punctate than lateral parts of these structures, which are very densely punctate with lunate punctures, with sparse, moderately long, silvery pubescence.

Apical ventrite (Figs 141–142): lunate punctures not coalescing near the lateral margin, not forming grooves; excision in ♂ broad, W shaped, with a narrow truncated flange at the centre, with long well developed parallel lateral spines (Fig. 141); ♀ narrower, U-shaped, with a moderately broad flange for its entire width, the lateral spines well developed, parallel to slightly divergent (Fig. 142).

Fore tibia: ♂ strongly curved, with a very small triangular tooth at apex, and a slightly developed setal brush on the anterior face at the apex; ♀ tooth even smaller, or absent.

Mid tibia: ♂ strongly curved, with an elongate depression along the ventral face (Figs 210–211); ♀ weakly curved and without a depression.

Aedeagus (Figs 90–91): parameres strongly constricted before the apical setae bearing part; apical setae bearing parts scarcely widened, about one third the total length of the parameres, apical half weakly chitinised, with numerous fairly long, slightly curved, spine-like setae, in addition to the usual long fine setae; median lobe subacute at the tip.

Ovipositor: not examined.

Comments. This species is most similar to M. costipennis . See comments on differences under that species.

Bionomics. Adults collected September to January, most records in November & December. Adults are mostly collected on Viminaria sp. and occasionally on Jacksonia spp. (Hanlon pers. comm.); also one record from Acacia sp. Larval host unknown.