Melobasis iridicolor Carter
Creators: name: Levey, Brian
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Buprestidae
Melobasis
Melobasis iridicolor

description: M. iridicolor Carter
(Figs 122, 135, 157, 158, 180, 181)
Melobasis iridicolor Carter 1923:93; 1929:284; Obenberger 1930:432; Bellamy 2002:155; 2008:1324.
Type locality: Northern Territory, Darwin.
Type specimens examined. Lectotype ♁ (MVMA) [here selected] Darwin/ Type ♁/ Type ♁/ Melobasis iridicolor Carter Id. by H.J. Carter. Paralectotype ♀ (SAMA) Port Darwin, N. Territory/ Type ♀ H.J.C/ Melobasis iridicolor Carter Id. by H.J. Carter. [Carter in his original description lists a third specimen from Cairns. This female specimen (SAMA) which I examined many years ago is not conspecific with Melobasis iridicolor].
Other specimens examined: N. Territory: 1♁ (BMNH) Groote Eylandt, 16.i.1925, G.H. Wilkins; 2♀ (ANIC) 12.34S 131.19E Fogg Dam, 53km E. by S. of Darwin N.T., 18 Nov. 1979, T. Weir; Queensland: 1♀ (QMA) Coleman River crossing W. of Musgrave, Qld., 14º47′55′′S 143º21′34′′E, 31 Dec. 1993, G.& A. Daniels, R. Eastwood, mv lamp.
Diagnosis. General diagnosis: length 8.6–9.4 mm; head green or golden green, sometimes with reddish copper reflections; pronotum predominantly golden green or blue green, with a pair of broad, purple to reddish purple, admedian vittae (the specimen from Coleman River Crossing does not have admedian vittae, but has reddish purple patches in the posterior half in the lateral quarter, extending along the basal margin towards the midline, and broadly along the lateral margin, where it becomes partly bluish violet); scutellum green to golden green; elytra purple-brown, purple to reddish purple with the following golden green, green, blue green to bluish violet markings: sutural vitta moderately broadly in basal fifth to sixth; broad lateral vitta extending from basal margin over the humeral callosity, along the lateral margin and epipleura to the level of the hind coxa or 1st ventrite, before deviating from the lateral margin, extending to apical sixth of elytra, narrowly connected to sutural vitta along basal margin; underside predominantly green, blue green, sometimes prosternal process with coppery reflections (prosternum, prosternal process, mesosternum, hypomeron and mesanepisternum reddish purple to purple in specimen from Coleman River Crossing); sparsely clothed with short inconspicuous silvery setae.
Head (Fig. 135): very densely (♀) to contiguously punctate (♁) with small strong, mostly round punctures; ♁ densely clothed with long silvery pubescence, partly obscuring the punctation; ♀ glabrous; spaces between the punctures very weakly microreticulate; clypeal excision scarcely developed, very shallow, with a narrow to very narrow reticulate impunctate border; clypeal peaks obtusely angled; clypeal angles absent; vertex flat, slightly more than half width of head across eyes when viewed from above; eyes strongly convex.
Antenna:slightly sexually dimorphic;♁ segments 3–10 expanded,segment 3 subtriangularly expanded, segments 4–10 with expansion quadrate, slightly petiolate at base; ♀ segments 4–10 expanded, segment 4 subtriangularly expanded, segments 5–10 with expansion quadrate, slightly petiolate at base.
Pronotum: 1.51–1.59× as wide at base as long in midline; anterior margin weakly bisinuate with a weakly developed median lobe, with a well developed entire beaded margin; posterior margin moderately strongly biarcuate; widest near basal third; lateral margins weakly rectilinearly diverging from basal angles to widest point, before rectilinearly converging to apical angles; basal angles slightly obtuse; as wide at base as elytra at base; lateral carina sharp very well defined, almost straight, about two-thirds to three-quarters complete; punctation in central half very dense to contiguous, consisting of transversely elliptical punctures forming transverse slightly sinuate series; punctation in lateral half dense to very dense, the punctures transversely oval next to the central half, becoming round towards the lateral margin; spaces between punctures weakly microreticulate; glabrous.
Scutellum: slightly elongate to quadrate, shield shaped, about one twenty-fifth to one thirtieth width of elytra at base; strongly microreticulate.
Elytra: 2.21–2.32× as long as wide at base; basal margin moderately strongly biangulate, slightly widening from base over the humeral callosities thence almost parallel sided to midlength, before narrowing to the rather broadly rounded apices; lateral margins in apical half, and apices serrate, with acute serrations, the serrations much smaller at the elytral apices; sutural margins very slightly raised in apical half; punctation of internal half of elytra very sparse to sparse, consisting of pin-prick and very small slightly lunate punctures, partly arranged in regular longitudinal series; punctation of external half dense to very dense, consisting of much larger transversely ovate punctures, forming transverse series near the lateral margin; without costae; moderately strongly microreticulate between the punctures.
Hypomeron: contiguously punctate with medium sized, very shallow, ovate and elliptical punctures, the bottom of the punctures strongly microreticulate, with sparse inconspicuous, silvery pubescence.
Prosternum: with a well defined broad bead at the anterior margin; the anterior margin at the same level, or slightly depressed relative to the area behind; prosternal process strongly widening distally, almost as wide as long at its widest point, very densely to contiguously punctate, with strong round punctures, glabrous.
Mesanepisternum: very strongly microreticulate, with a few, very inconspicuous, very shallow setae bearing punctures.
Central part of metaventrite, inner part of metacoxa glabrous, sparsely punctate with small weak mostly pin-prick punctures; lateral parts punctate with mostly large shallow, coalescent, lunate punctures; abdominal ventrites glabrous and moderately densely, weakly punctate, with small mostly lunate punctures in central-third, laterally with larger coalescent lunate punctures, with very sparse very inconspicuous silvery pubescence.
Apical ventrite (Figs 157, 158): lunate punctures coalescing to form grooves parallel to the lateral margin; excision in ♁ broad, W shaped, with a narrow flange produced at the centre as a wide triangular lobe, with well developed, short, slightly divergent lateral spines (Fig. 157); ♀ moderately broad, deep U-shaped, the narrow flange very slightly to strongly produced at the centre as an acutely triangular lobe, the lateral spines long, well developed, slightly divergent (Fig. 158).
Fore tibia: ♁ strongly curved, with a setal brush at the apex on the anterior face; ♀ with a less developed setal brush, less curved.
Mid tibia: ♁ strongly curved without teeth on the ventral face; ♀ slightly curved, without teeth.
Aedeagus (Figs 180, 181): parameres asymmetrical; apical setae bearing part without spine-like setae, only the usual long fine setae present; median lobe asymmetrical at tip.
Ovipositor: not examined.
Comments. This species is most similar to M. macqueeni sp. n. The pronotal shape is slightly different being widest near the basal third, with the lateral margins converging rectilinearly to the apical angles from the widest point in M. iridicolor (in M. macqueeni sp. n. the pronotum is widest at or just behind the midlength and the lateral margins converge curvilinearly to the apical angles from the widest point). The pronotal colour pattern in the two species is different but does vary intraspecifically and may not be diagnostic if more material from a wider range of localities were available (see descriptions).The aedeagus is slightly different in shape with the parameres slightly more abruptly narrowing to the apical setae bearing parts in M. iridicolor in comparison to M. macqueeni sp. n., and the apex of the median lobe is assymetrical in M. iridicolor.
Bionomics. Adults collected from November to January. Larval host unknown.
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 78-79, DOI: 10.11646/zootaxa.5302.1.1, http://zenodo.org/record/8043117