Melobasis barkeri, 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 : 11-12

M. barkeri sp. n.

(Figs 37, 96–97, 147–148, 166)

Type locality: Western Australia, Burracoppin .

Type specimens examined. Holotype ♂ ( AMSA) [mounted with 2♂, 1♀ on a single card bearing the following information on the underside of the card; holotype indicated by me on the upperside of card by the word Holotype]: Melobasis Burracoppinensis Br. [manuscript name], on Acacia fragilis, Burracoppin W.A. 2.10.1939 . Paratypes as follows: 2♂, 1♀ ( AMSA) mounted on card with holotype ; 2♂, 1♀ ( ANIC) [on a single card with the following information on underside of card] Burracoppin, W.A. 5.10.38 . on high Acacia eremophila / [on upperside of card the following information] 4, Southern Cross , W.A. H.W. Brown ; 3♂, 1♀ ( TMSHC) as above but 12.11.1937 ; 1♂, 3♀ ( TMSHC) Burracoppin , W.A. on Acacia eremophila , 5.10.1938 , H.W. Brown; 1♂, 2♀ ( TMSHC) as above but 20.10.1936 ; 3♂ ( TMSHC) Burracoppin , W.A. on tall Acacia eremophila , 4.10.1938 , HWB; 3♂, 1♀ ( TMSHC) Burracoppin , W.A. on Acacia eremophila , 12.11.1937 , HWB; 2♂, 2♀ ( TMSHC) Burracoppin , W.A. on Acacia fragilis , 2.[?].1939, HWB ; 4♂, 1♀ ( BLC, WAMA) Southern Cross , W.A. H.W. Brown ; 1♂, 2♀ ( TMSHC) 2.5 km S. of Yellowdine, W.A. T.M. Hanlon & M. Powell, 22 Oct. 2005 , on Acacia leaves ; 1♂ ( TMSHC) N7 T, 34 km E. of Yellowdine, 3 Nov. 2001 , T.M.S. Hanlon, on narrow leaf Acacia ; 1♀ ( MPC) 64 km E. Yellowdine , W.A. Sep. 22 1994 , Acacia, M. Golding /M. Powell; 1♀ ( MPC) 24 km S. Marvel Loch , W.A. Oct. 27 1991 , Acacia, M. Golding. M. Powell ; 3♂ ( MPC) Lake Hurlestone ( NW), W.A. 26.11.2005 , narrow leaved Acacia lvs. M. Powell. D. Knowles; 3♂ ( MPC) as above but 27 Nov. 2005 ; 1♂ ( MPC) 8 km W. Wialki , W.A. Sep. 23 1978 , Acacia lvs., D. Knowles; 1♂, 6♀ ( BLC, SAMA) 3 mls West Wialki , W.A. 2.ix.1970 , Acacia, S. Barker, Barker Coll. ; 1♂, 1♀ ( TMSHC) Ankertell, H.W. Brown ; 1♀ ( ANIC) Lake Grace W.A., 16-10- 1970 , K. & E. Carnaby.

Diagnosis. General diagnosis: length 9.8–12.3 mm; upperside greenish to brownish bronze; underside greenish to brownish bronze, abdomen with extensive reddish violet reflections; anterior face of fore femora, tibia and tarsi green; underside laterally moderately densely clothed with moderately long silvery pubescence, most of prosternum, prosternal process, mesosternum, and central parts of metaventrite and abdominal ventrites glabrous or very sparsely pubescent.

Head (Fig. 166): contiguously punctate with very small round strong punctures which are stronger and denser in ♂; densely (♀) to very densely clothed (♂) with long silvery pubescence which partly obscures the punctation; rims of the punctures microreticulate; clypeal excision shallow U- or V-shaped, with a fairly broad, complete, impunctate, shiny or microreticulate border; clypeal peaks right angled, with a slightly to fairly well defined clypeal angle; vertex flat, half width of head across eyes when viewed from above; eyes very strongly convex.

Antenna: not sexually dimorphic; segment 3 weakly triangularly expanded or slightly widening apically, subcylindrical about 2.0–2.5 × as long as wide at its widest point, 4 weakly triangularly expanded, 5–11 with expansion almost quadrate.

Pronotum: 1.35–1.52 × as wide at base as long in midline; anterior margin strongly bisinuate, with a moderately well developed, broad median lobe; with a complete narrow but well defined beaded margin; posterior margin weakly biarcuate; widest at basal third, mid-length or apical third; lateral margins almost rectilinearly diverging from basal angle to widest point (sometimes with a slight sinuation just anterior of the basal angles), before weakly converging to apical angles; basal angles right angled; as wide as elytra at base; lateral carina almost straight about two-thirds to three-quarters complete; punctation in central fifth moderately dense consisting of slightly transversely ovate punctures; punctation lateral to this area dense consisting of very strongly transverse elliptical punctures arranged in slightly sinuate series, closer to the lateral margin becoming round; rarely with traces of an impunctate median line, sparsely clothed with moderately long silvery pubescence very close to the lateral margin and more widely in the anterior half.

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

Elytra 2.32–2.71 × as long as wide at base; basal margin very weakly biangulate; slightly widening from the base over the humeral callosities thence parallel sided to slightly widening to mid-length, before narrowing to the rounded or sub-acute apices; lateral margins in apical half to third and apices with moderately coarse acute serrations; sutural margins slightly raised in apical two-thirds; each elytron with 2 approximately equidistant costae and traces of a 3rd; 1st costa extending from basal quarter to apical fifth; 2 nd costa less well defined, extending from basal third to apical sixth; 3 rd costa sometimes scarcely discernible;1 st costa almost impunctate; subsutural depression and area between 1 st and 2 nd costae sparsely punctate with very small round, ovate and pin-prick punctures; lateral to the 2 nd costa moderately densely punctate with small mostly elliptical punctures which become larger and denser towards the lateral margins where they form contiguous transverse series; moderately strongly microreticulate.

Hypomeron: very densely to contiguously punctate with small, shallow mostly round punctures, clothed with moderately dense, moderately 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: 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 to contiguously punctat with imbricate and lunate punctures, partly concealed by moderately dense long silvery pubescence.

Apical ventrite (Figs 147–148): lunate punctures coalescing near the lateral margin but not forming grooves; excision in ♂ broad, W shaped, with a moderately broad, curved, subtruncate, flange at the centre, with rather short, well developed, slightly incurved, lateral spines (Fig. 147); ♀ narrow, U-shaped, without a visible flange, the lateral spines well developed, parallel (Fig. 148).

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

Mid tibia: ♂ rather strongly curved with an elongate depression along the ventral face; ♀ almost straight and without a depression.

Aedeagus (Figs 96–97): parameres strongly but not abruptly constricted before the apical setae bearing part; apical setae bearing parts slightly widened, almost half 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 truncate at the tip.

Ovipositor: not examined.

Comments. This species is most similar to M. soror basicostata ssp. n. It differs most significantly in the shape of the flange of the apical ventrite of the male (compare Figs, 145 & 147), the form of the aedeagus (compare Figs 92 & 96), the less well developed elytral costae, and in the reddish violet reflections of the abdomen. These taxa as far as is known have allopatric distributions.

Etymology. This species is named after Shelley Barker the foremost taxonomist of Australian Buprestidae , who kindly loaned me many species of Melobasis collected by himself, including this one.

Bionomics. Adults collected from September to November on Acacia spp. Larval hosts unknown.