Melobasis nervosa, (Boisduval)

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 : 34-36

M. nervosa (Boisduval)

(Figs 25, 79–80, 131–132, 165, 175)

Buprestis nervosa Boisduval 1835:77 ; Hope 1836:9; Laporte & Gory 1837:121; Saunders 1868:18; Gemminger & Harold 1869:1383; Saunders 1871: Masters 1886:74; Tepper 1887: 16; Kerremans 1892:105; 1903:158; Goudie 1920:30; Carter 1929:285; Obenberger 1930:433; Burns & Burns 1992:8; Webb 1994:85; Turner & Hawkeswood 1997a:257 –260; 1997b:261–264; Faithfull 1997:23; Cowie 2001:28; Bellamy 2002:157; 2008:1327; Hawkeswood 2011:9 –10; Bellamy et al 2013:58 –59. Type locality: Australia (Nouvelle Hollande)

Melobasis costata Thomson 1879:87 (preocc. M. costata Macleay 1872 ) (stat. rev. not a synonym of M. interstitialis Blackburn); Blackburn 1890 :146; Carter 1923:82; Obenberger 1930:432; Carter 1931:108; Bellamy 2002:154; 2008:1324. Type locality: Tasmania

Type specimens examined. Buprestis nervosa Boisduval Holotype ♀ (MNHN) Durville P. West/ Museum Paris d’Urville/ nervosa / M. nervosa Boisd. Tasmanie M.J. Urville.

Melobasis costata Thomson Lectotype here designated ♀ (MNHN), costata (Lafert) Tasmanie / Th Type/ Tasman / costata Laf. M. ss/ Ex Musaeo James Thomson.

Other specimens examined. South Australia: Adelaide; Gawler; Harvey’s Return, Flinders Chase, Kangaroo Island; Koala Park, Kangaroo Island; Kuipo Colony, near Myoponga; Lucindale; Marble Range; Montacute Heights, Adelaide; Parkside; 6mls W. of Penneshaw, Kangaroo Island; Port Lincoln; Reed Beds, Adelaide; 16 mls W. of Vivianne Bay, Kangaroo Island; Waitpinga Beach; Yorketown. Victoria: Beaconsfield; Brighton; Upper Buckland River; Buln Buln East; Gembrook; Healsville; Launching Place; Melbourne; Mittagong; Moe; Mount Macedon; Noble Park; Porepunkah; Prahran; Wannon; Warburton; Wilsons Promontory; Woori Yallock. Tasmania: Kingston; Launceston; Liffey Valley; Mount Wellington; Orford; River Isis; Sheffield; Trevallyn Lann; New South Wales: Amosfield; Armidale; Bombala, Coolangubra State Forest; Borenore; Caparra; Colong District, near Yerranderie; Cox’s Road, N.E. of Deepwater; Ebor, 24 km S.W. of; Forest Reefs; Glenbrook, 8 km N.E. of; Glen Innes; Ginkin, Gurnang State Forest; Herding Yard Gully, 2 km W. of Amosfield; Hill End; Jenolan Caves; Kangaroo Valley; Killara; Macquarie Pass, W. of Albion Park; Newnes; Tea Tree Creek, Armidale; Yarrat State Forest; Queensland: Fletcher; Mount Glorious; Stanthorpe. Specimens in AMSA, ANIC, BLC, BMNH, CLBC, DCC, FCNSWA, UQA, IRSNB, MVMA, NMPC, QMA, SAMA, UQA, WAMA, ZMHB.

Diagnosis. General diagnosis: length 11.0– 15.5 mm; largely greenish to blackish bronze, the elytral costae and pronotum often with a reddish violet reflection; lower three-quarters of head in ♂ with a coppery green reflection, in ♀ with a dull green reflection in lower half; underside laterally moderately densely clothed with long silvery pubescence.

Head (Fig. 165): contiguously punctate, with small round to ovate punctures, which are slightly stronger and denser in ♂; in some specimens the punctures coalesce to form short dorso-ventrally orientated series; densely (♀) to very densely clothed (♂) with long silvery pubescence, which partly obscures the punctation; ridges between the punctures weakly microreticulate to shiny; clypeal excision very shallowly excised, usually with a narrow, complete, impunctate, weakly microreticulate border, sometimes only developed at the centre; clypeal peaks obtusely angled to almost rounded, without a defined clypeal angle; vertex flat, slightly less than half width of head across eyes when viewed from above; eyes very strongly convex.

Antenna: not sexually dimorphic; segment 4, or 4 and 5 triangularly expanded, segments 5–11, or 6–11 with expansion almost quadrate; segment 3 subcylindrical, slightly widening distally, about 2–3 × as long as wide at its widest point.

Pronotum: 1.28–1.48 × as wide at base as long in midline; anterior margin strongly bisinuate, with a moderately well developed, broad, sometimes subtruncate, median lobe, with a narrow but well defined beaded margin; posterior margin weakly biarcuate; widest at mid-length to 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 moderately strongly converging to apical angles; basal angles acute; as wide or very slightly narrower at base than elytra at base; lateral carina almost straight, about half to three-quarters complete; punctation in centralquarter to central-third sparse, consisting of small, round and pin-prick punctures; punctation in lateral two–thirds to three-quarters dense to very dense, consisting of small transverse elliptical punctures nearer the centre, becoming denser, larger, and mostly round and ovate punctures laterally; sometimes with an incomplete impunctate median line; sparsely to moderately densely clothed, with moderately long, silvery pubescence in lateral quarter.

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

Elytra 2.59–2.81 × as long as wide at base; basal margin very weakly biangulate; strongly widening from the base over the humeral callosities, thence parallel sided to mid-length, before narrowing to the rounded or sub-acute apices; lateral margins in apical third and apices, with moderately coarse acute serrations; sutural margins slightly raised in apical two-thirds; each elytron with 4 approximately equidistant costae; 1 st costa extending from base almost to apex; 2 nd costa extending from base to apical sixth, sometimes almost fusing with 1st costa at apical sixth; 3 rd costa extending from near the humeral callosity to apical fifth; 4 th costae, and sometimes 3 rd very poorly defined; the 1 st, 2 nd and sometimes 3 rd costae almost impunctate; subsutural depression sparsely punctate, with very small round punctures; area between 1 st and 2 nd costae moderately densely punctate, with small mostly elliptical punctures, remainder of elytra densely to very densely punctate, with larger transverse elliptical punctures, which often form transverse series; shiny to weakly microreticulate.

Hypomeron: very densely to contiguously punctate, with small, shallow, mostly round punctures, with moderately 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 (Fig. 175): shiny, with shallow round punctures mostly concentrated at the anterior internal angle, and along the anterior margin, with long silvery pubescence densest at the anterior internal angle.

Central part of metaventrite, inner part of metacoxa, central part of abdominal ventrites, glabrous, more sparsely and weakly punctate than lateral parts of these structures, which are very densely to contiguously punctate, with small imbricate and lunate punctures, partly concealed by moderately dense, long, silvery pubescence.

Apical ventrite (Figs 131–132): lunate punctures mostly well separated, rarely coalescing near the lateral margin, not forming grooves; excision in ♂ broad, slightly W shaped, with a moderately broad curved flange at the centre, with moderately long, well developed, slightly divergent lateral spines (Fig. 131); ♀ narrower, U-shaped, with a moderately broad flange for its entire width, the lateral spines well developed, slightly divergent (Fig. 132).

Fore tibia: ♂ slightly curved, with a 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 numerous small teeth along the ventral face on the posterior edge, and a shallow elongate depression along the ventral face; ♀ almost straight, and without teeth or depression.

Aedeagus (Figs 79–80): parameres strongly but not abruptly constricted before the apical setae bearing part; apical setae bearing parts slightly widened, 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 very similar to, and possibly most closely related to M. soror soror , but is usually larger, and the aedeagus is different. Of the larger unicoloured species, with two or three well defined elytral costae, this species is superficially most like M. costifera , but can be easily distinguished from this species by the absence of an enlarged tooth at the apex of the elytra, and by the elytra being more strongly widened over the humeral callosities, the mesanepisternum being shiny, with most of the surface being impunctate, the different form of the flange of the apical ventrite in the ♂, the curved mid tibia in the ♂, and differences in the aedeagus.

Bionomics. Adults collected from July to February (mostly October to December) mostly from Acacia spp.; A. melanoxylon (Hanlon pers. comm.). Larval hosts Acacia spp. (see Hawkeswood 2011:9–10; Bellamy et al 2013:58–59).