Melobasis vertebralis subsp. cuneata, 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 : 44-46

M. vertebralis cuneata ssp. n.

(Figs 12–15, 55–58, 116–117, 156, 198–199)

Type locality: New South Wales, Sims Gap .

Type specimens examined. Holotype ♂ ( ANIC), Sims Gap W. of Rankins Springs, N.S.W., 15 Nov. 1984, G. Williams, on broad-leaved Acacia . Paratypes as follows: 1♂, 2♀ ( BLC, GWC), same data as holotype ; 3♂, 4♀ ( BLC, ANIC), Sims Gap nr. Rankins Springs, N.S.W., 15.xi.84 & 7.xi.85, Acacia sp., S. &W. Watkins ; 1♂, 1♀ ( ANIC,), Condobolin, N.S.W., 15.x.00 / W.W. Froggatt Collection ; 1♀ ( BMNH) same as previous but ex, Coll. H.J. Carter, 1935-9 ; 2♀ ( BMNH), Baan Baa, N.S.W. 27.x.08. G.E. Bryant / G. Bryant Coll. B.M. 1926-86 ; 1♂, 3♀ ( BLC, ANIC), Mt Kaputar Nat. Pk., 24.xi.85, Acacia, S. Watkins ; 1♀ ( GWC); via Mt Kaputar N.P. approx. 40km N.E. Narrabri, N.S.W. 24 Nov. 1985, G. Williams, ex Acacia foliage ; 1♀ ( CLBC), Australia: N.S.W. 44 km N.E. Narrabri, 12.xii.1986, G.A. Williams / beating foliage Acacia sp . 2♂ ( ANIC) M. vertebralis Fletcher / S.R.E. Brock collection donated to ANIC 1987 ; 2♀ ( ANIC) Fletcher, 4.12.47, E. Sutton ; 2♂ ( ANIC) Fletcher S.Q., Nov.1945. All with labels PARATYPE Melobasis vertebralis cuneata ssp. n. B. Levey 2012.

Other specimens examined. New South Wales: 1♂, 2♀ (BLC, FCNSWA), N.S.W. Cobar, 20 Jan. 1987, A. Salmon ex Acacia sp. timber em. Oct. 1987 ; 1♂ ( FCNSWA), N.S.W. Coonabarabran, Warrumbungles N.P., 6.10.86 , G.A, Webb, on Beyeria viscosa; 1♀ ( TMSHC) Round Hill Reserve , T.M.S. Hanlon, reared from Acacia doratoxylon , coll. 15 Sept. 2001 , emerged 29 Sept. 2004; 1♂, 2♀ ( TMSHC, ANIC) N.S.W. Sandy Hollow, 9.xi.96 & 5.xi.97 ; 1♂ ( ANIC) Weddin Mts. N.S.W., 1–3 Oct. 1977 , K.R. Pullen; 1♀ ( TMSHC) Hazel. [Hazelbrook] Nov. 1932 , B. Stoyles.

Diagnosis. General diagnosis: length 11.9–15.5 mm; colour and markings as in M. vertebralis vertebralis except scutellum sometimes bright coppery, elytra sometimes with the blackish lilac colour extending laterally beyond the 1 st costa in the basal-quarter or basal-third, and with the 2 nd and 3 rd costae at mid-length similarly coloured; in the specimens from Sandy Hollow and Weddin Mts. the blackish lilac colour is more extensive lateral to the first costa with and elongate macula at mid-length between the 2 nd and 3 rd costae which extends obliquely towards the apex and reaches the lateral margin (Fig. 15); the underside reddish copper in central parts, laterally with extensive blackish green reflections; laterally densely clothed with long silvery pubescence, but less dense than in M. vertebralis vertebralis ; central part of the prosternum, prosternal process, mesosternum, central parts of metaventrite and abdominal ventrites glabrous.

Head (Fig. 156): as in M. vertebralis vertebralis .

Antenna: ♂ as in M. vertebralis vertebralis ; ♀ weakly serrate from segment 4–10, the expanded part of segments very weakly triangular; segments more elongate than in M. vertebralis vertebralis , segments 4–7 about 3– 4 × as long as wide at widest point, segments 8–10 slightly progressively shorter.

Pronotum: 1.35–1.45× as wide at base as long in midline (n=7); other characters as in M. vertebralis vertebralis .

Scutellum: as in M. vertebralis vertebralis .

Elytra: 2.41–2.60 (mean=2.53) × as long as wide at base (n=7); other characters as in M. vertebralis vertebralis .

Hypomeron: as in M. vertebralis vertebralis but punctation less obscured by the less dense pubescence.

Prosternum: as in M. vertebralis vertebralis .

Mesanepisternum: as in M. vertebralis vertebralis .

Central part of metaventrite and inner part of metacoxa and abdominal ventrites as in M. vertebralis vertebralis .

Apical ventrite (Figs 116–117): lunate punctures coalescing to form grooves parallel to the lateral margin; excision in ♂ broad, W shaped, with a narrow bisinuate flange produced at the centre as a truncated lobe, with well developed, long, parallel lateral spines (Fig. 116); ♀ narrow, deep U-shaped, the flange poorly developed, the lateral spines well developed, parallel, to slightly convergent (Fig. 117).

Fore tibia (Figs 198–199): as in M. vertebralis vertebralis .

Mid tibia: as in M. vertebralis vertebralis .

Aedeagus (Figs 55–58): elongate, the parameres very strongly almost rectilinearly narrowing from the basal piece to the apical setae bearing parts, apex of median lobe rounded.

Comments. I have dissected a male specimen from Mourangee, Edungalba which has the elongate aedeagus, flange of the apical sternite, and elytral markings characteristic of this subspecies but has the denser underside pubescence seen in M. v. vertebralis . This specimen is mounted on the same card as a dissected male which has the less elongate aedeagus and the flange of the apical sternite, elytral markings, and denser underside pubescence characteristic of M. v. vertebralis , and a female with the latter two characteristics. The data on the underside of the card is as follows, and might indicate that different hosts are being utilised in this area by the two subspecies. “on lambstail wattle [ Acacia leiocalyx ?] & ironwood wattle [ Acacia excelsa ?] / black wattle [ Acacia decurrens /] [specimens] 1 & 2. 5.1.45, [specimens 1 & 2?] 3. Jan 46. I have also seen four female specimens from the same locality which have elytral markings like M. v. cuneata , and dense underside pubescence characteristic of M. v. vertebralis . Two of these specimens were collected on Acacia decurrens . It seems likely that there is genetic introgression occuring between these subspecies in this part of Queensland. I have also seen a dissected male (ANIC) from Weddin Mts., New South Wales which has the aedeagus shape intermediate in form between the two subspecies (Fig. 58), with the apical sternite, elytral markings, and underside pubecence characteristic of M. v. cuneata .

The shape of the flange of the apical ventrite in the male of M. v. cuneata is more similar to that M. brevimaculata than to that of M. vertebralis vertebralis , and might indicate that M. brevimaculata evolved from M. vertebralis cuneata , and has subsequently become sympatric with M. vertebralis vertebralis . If this scenario is correct one might be justified in treating the subspecies of M. vertebralis as full species.

Etymology. This subspecies is named for the narrow truncated central lobe of the flange of the apical sternite in the male.

Bionomics. Adults have been collected in October to December on Acacia spp. foliage. Larval host Acacia doratoxylon .