Melobasis costata Macleay (J Mackay, Q. BLC 1872
Creators: name: Levey, Brian
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Buprestidae
Melobasis
Melobasis costata

description: M. costata Macleay
(Figs 2, 19, 36, 37, 58, 59)
Melobasis costata Macleay 1872:240; Kerremans 1885:136; Masters 1886:93; Blackburn 1890:146; Kerremans 1892:104; 1903:158; Carter 1923: 76; 1929:284; Obenberger 1930:429; Hawkeswood 1978:260; Cowie 2001:21, 26; Bellamy 2002:148; 2008:1318; Bílý & Volkovitsh 2005:16 (larval description); Hawkeswood 2011:3; Bellamy et al. 2013:56.
Type locality: Queensland, Gayndah.
Melobasis epistomalis Obenberger 1942:99; Bellamy 2002:151; 2008:1320. Syn. nov.
Type locality: Queensland.
Type specimens examined. M. costata Macleay [The original description does not indicate how many specimens were used in describing the species. I found four specimens from Gayndah in AMSA and ANIC which are probable syntypes. Lectotype here designated, ♁ (ANIC), Gayndah/ Melobasis costata Macl. Gayndah / Lectotype [round label]/ my lectotype label. Paralectotypes 1♁ (ANIC), Gayndah/ Syntype Melobasis costata Macl. [label added by E.B. Britton]/ Paralectotype [round label]/ my paralectotype label. 1♀ (AMSA) K32109/ Melobasis costata McL. W. Gayndah/ Holotype / my paralectotype label. 1unsexed [abdomen missing] (AMSA) K32109/ Holotype / my paralectotype label.
M. epistomalis Obenberger Holotype ♀ (NMPC), Queensland Collectio Dr Obenberger/ Typus/ Melobasis epistomalis m. Type det Dr. Obenberger / Mus. Nat. Pragae Inv 22015/ My determination label.
Other specimens examined. Queensland: Banana; Barakula State Forest, 26.24S 150.815E; Barakula State Forest, 26.298S 150.876E; Dalby; Chinchilla, 3km E.; Dawson District; Edungalba; Edungalba, Mourangee, 3 km W.; Eidsvold; Lotus Creek; Mackay; Marmor; Milmerran; Mt. Nebo, 67 km N.W.; Mt. Robert, 5km S.W., 21.24S 148.27E; Rockhampton; Stanthorpe; Stone Dam, 16 km N. Edungalba; Tamborine Mt.; Taroom, 6km N., 25.5961º S 149.719º E. New South Wales: Sydney [I suspect this specimen is either wrongly labelled or that of an imported specimen, as I have seen no specimens other than from Queensland]. Specimens in AMSA, ANIC, BCM, BLC, BMNH, BPBM, GHNC, IRSNB, MMSA, MPC, MVMA, NMWC, QMA, SAMA, WAMA, ZMHB.
Diagnosis. General diagnosis: length 8.6–13.4 mm; lower half of head in ♁ green, becoming golden green or coppery near the frontoclypeal margin, upper half dull green, sometimes with dull reddish purple reflections, head in ♀ greenish or brownish bronze, sometimes with dull reddish purple reflections in the upper half; pronotum and elytra greenish to brownish bronze often with dull reddish purple reflections on the pronotum and the elytral costae; underside predominantly greenish to blackish bronze; anterior faces of fore femora and tibia, and antenna and sometimes prosternal process bright green in ♁, duller green in ♀; underside in ♁ densely clothed with long silvery pubescence on the centre of the prosternum, prosternal process, mesosternum, metaventrite close to the midline, inner edge of metacoaxa, and ventral surfaces of the trochanta and inner half of femora on all legs; the rest of the underside except for mesanepisternum, which is almost glabrous, densely clothed with moderately long silvery pubescence; centre of prosternum, prosternal process, mesosternum, and central half of metaventrite in ♀ glabrous or very sparsely clothed with short silvery pubescence, rest of underside densely clothed with moderately long silvery pubescence except for the mesanepisternum, which is almost glabrous.
Head (Fig. 19): ♁ contiguously punctate with very small strong punctures, the narrow rims of the punctures shiny; ♀ very densely punctate with slightly larger shallower punctures, the spaces between the punctures weakly microreticulate; ♁ very densely clothed with moderately long silvery pubescence which partly obscures the punctation; ♀ moderately densely clothed with moderately long silvery pubescence, which does not obscure the punctation; clypeal excision a very narrow U to V shaped notch, between broad almost truncate to slightly sinuate lobes, with the clypeal peaks and clypeal angles only slightly developed; vertex flat, about one third width of head across eyes when viewed from above; eyes very strongly convex.
Antenna: not sexually dimorphic; segments 3–10 expanded, segment 3 and sometimes 4 subtriangularly expanded, segments 4 (5)–10 with expansion quadrate, slightly petiolate at base.
Pronotum: 1.46–1.68× as wide at base as long in midline; anterior margin moderately strongly bisinuate with a broad well developed median lobe, which is sometimes subtruncate, with a well developed entire beaded margin; posterior margin weakly bisinuate; widest just behind midlength to near basal third; lateral margins weakly rectilinearly diverging from basal angles to widest point, sometimes with a marked sinuation just anterior to the basal angle; anteriorly weakly curvilinearly to almost rectilinearly converging from widest point to apical angles; basal angles nearly right angled; slightly narrower at base to as wide as elytra at base; lateral carina sharp very well defined, almost straight, about two-thirds to three-quarters complete; punctation in central fifth sparse to moderately dense, consisting of small round and ovate punctures, sometimes with a partial to almost complete impunctate median line; punctation in lateral four-fifths dense to very dense, becoming contiguous near the lateral margin, consisting of transversely ovate to transversely ellipsoidal punctures nearer the centre, and round punctures near the lateral margin; spaces between punctures weakly to moderately strongly microreticulate; moderately densely clothed with silvery pubescence near lateral margin and more broadly near apical angle, glabrous elsewhere.
Scutellum: slightly transverse, shield shaped, about one-eleventh to one-thirteenth width of elytra at base; moderately strongly microreticulate.
Elytra: 2.27–2.40× as long as wide at base; basal margin weakly biangulate, moderately strongly to strongly widening from base over the humeral callosities thence almost parallel sided to midlength, before narrowing to the rounded apices; lateral margins in apical half and apices serrate, with acute serrations; sutural margins slightly raised in apical half; each elytron with three well defined costae, the inner two extending almost from base to apical sixth where they sometimes fuse, the third costa usually less well defined, extending from posterior of the humeral callosity to apical quarter; scarcely raised sutural boss delineated at its lateral edge by a short costa; area between suture and 1 st costa sparsely punctate with small ovate punctures; areas between 1 st and 2 nd, and 2 nd and 3 rd costae moderately densely punctate with slightly transversely ellipsoidal punctures; area lateral to 3 rd costa densely punctate with slightly larger transversely ellipsoidal punctures; moderately strongly microreticulate between the punctures.
Hypomeron: contiguously punctate with small, shallow round and ovate punctures, in part obscured by dense, long, silvery pubescence.
Prosternum: with a narrow bead at the anterior margin; the anterior margin at about the same level as the area behind; densely clothed with long silvery pubescence in ♁, glabrous at centre except close to the beaded margin in ♀; prosternal process strongly widening distally, less wide than long at its widest point, densely to very densely punctate with small round punctures, largely obscured by dense, long silvery pubescence in ♁, sparsely to very sparsely punctate with very small round and pin-prick punctures, glabrous in ♀.
Mesanepisternum: sparsely to very densely punctate with small variably shaped and pin prick punctures over most of the surface, with a band of long silvery pubescence associated with larger, round, shallow punctures, along the anterior margin.
Central part of metaventrite close to the midline and inner edge of metacoxae densely punctate with small punctures, clothed with long silvery pubescence in ♁; sparsely to very sparsely punctate, glabrous to sparsely pubescent, with shorter silvery pubescence in ♀; punctation of lateral parts in both sexes composed of very dense, shallow, mostly round punctures, partly obscured by moderately long silvery pubescence; abdominal ventrites moderately densely clothed with moderately long silvery pubescence at centre, very densely clothed with moderately long silvery pubescence laterally, which in part obscures the punctation; punctation composed of small elongate lunate punctures, which are dense at centre and very dense to contiguous laterally.
Apical ventrite (Figs 36, 37): lunate punctures coalescing to form grooves parallel to the lateral margin; excision in ♁ broad, W shaped, with a moderately broad bisinuate flange, produced at the centre as a small round or subtruncate lobe, with well developed, moderately long, slightly divergent lateral spines (Fig. 36); ♀ narrower, U-shaped, with a moderately broad straight or slightly bisinuate flange, the lateral spines moderately long, slightly divergent (Fig. 37).
Fore tibia: ♁ slightly curved, with a setal brush in apical quarter on the anterior face; ♀ with tibia almost straight, and setal brush less developed.
Mid tibia: ♁ slightly curved, slightly swollen, with a long moderately deep setae-filled depression on the ventral face; ♀ almost straight, without a setae filled depression on the ventral face.
Aedeagus (Figs 58, 59): parameres with apical setae bearing part with numerous, small, spine like setae, in addition to the usual long fine setae; apex of median lobe narrowly truncate at tip.
Ovipositor: not examined.
Comments. This species is most likely to be confused with the probably closely related M. oculata sp. nov. which is sympatric with it. The form of the frontoclypeus is the easiest way to distinguish between the two species. Also as indicated in the key the shape of the punctures near the midline of the pronotum is different, and the shape of the two species is measurably different (see elytral width to length ratios in the descriptions). Other small differences are found in the shape of the flange of the excision of the apical ventrite of the male; the development of the depression on ventral face of the mid tibia in the ♁ (see descriptions); the aedeagi of the two species are very similar, but the parameres of M. costata are slightly less strongly narrowed in the apical half in the specimens dissected (compare Figs 58 & 60).
Bionomics. Adults collected on dead Brigalow, Acacia harpophylla (Fabaceae). One specimen collected on Casuarina (Casuarinaceae), specimen from 3 km E. of Chinchilla, 7.1.1979, S. Barker (AMSA). Also recorded on Themeda australis (Poaceae), recorded in Bellamy et al. 2013. The record of M. costata from Allocasuarina (Casuarinaceae) in Cowie 2001 is undoubtedly incorrect as M. costata does not occur in Tasmania and the figured specimen is a different species. Adults collected from October to January. Larval host Acacia harpophylla.
description: Published as part of Levey, Brian, 2023, A revision of the Australian species of the genus Melobasis Laporte & Gory 1837 (Coleoptera: Buprestidae), Part 3 (Revision of the azureipennis, cupricollis, iridicolor and melanura species groups), pp. 1-100 in Zootaxa 5302 (1) on pages 17-23, DOI: 10.11646/zootaxa.5302.1.1, http://zenodo.org/record/8043117