Melobasis rufoviolacea, Levey, 2023

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), Zootaxa 5302 (1), pp. 1-100 : 86-87

M. rufoviolacea sp. n.

( Figs 123 , 136 , 159, 161 , 182, 183 )

Type locality: Queensland , 12 km S.S.E. of Heathlands [Cape York] .

Type specimens examined. Holotype ♁ ( ANIC) 11.51S 142.38E QLD, 12km SSE Heathlands , 15–26 Jan. 1992, I. Naumann, T. Weir, at light.

Diagnosis. Only ♁ known. General diagnosis: length 6.72 mm; head blue black, narrowly golden to coppery along the fronto-clypeal margin and upper margin of vertex; pronotum golden green, with extensive reddish purple reflections in central third, coppery along the lateral margin in basal half; elytra mostly reddish violet, golden green basal and lateral to the humeral callosity and on the epipleura to the level of the hind coxa; underside green with extensive coppery and reddish purple reflections; glabrous, except for very fine short inconspicuous seta on parts of the underside.

Head ( Fig. 136 ): very densely punctate with small, round and slightly ovate punctures; glabrous; spaces between punctures moderately strongly microreticulate; clypeal excision broad, very shallow, arcuate, without an impunctate border; clypeal peaks slightly obtusely angled, clypeal angles weakly indicated; vertex flat, about half width of head across eyes when viewed from above; eyes strongly convex.

Antenna: segments 4–10 expanded, segment 4 with expansion subquadrate, segments 5–10 with expansion quadrate; about 2.0 x as long as wide, slightly petiolate at base.

Pronotum: 1.56x as wide at base as long in midline; anterior margin moderately strongly bisinuate, with a broad well defined median lobe, with a narrow entire beaded margin; posterior margin weakly biarcuate; widest at basal third; lateral margins strongly, almost rectilinearly diverging from basal angle to widest point, before strongly, almost rectilinearly converging to apical angles; basal angles slightly acute; slightly narrower at base than elytra at base; lateral carina slightly curved, about two-thirds complete; punctation in central half dense to very dense, consisting of rather weak, transversely oval and elliptical punctures, with a narrow, almost complete, impunctate median line; punctation in lateral half very dense, the punctures stronger, mostly round; spaces between punctures moderately strongly microreticulate; with a small elongate punctiform depression just anterior to the scutellum; glabrous.

Scutellum: shield shaped, about as long as wide, about one-twentieth width of elytra at base; microreticulate.

Elytra: 2.24x as long as wide at base; basal margin weakly biangulate, slightly widening from base over the humeral callosities thence almost parallel sided to midlength, before narrowing to the broad, rounded apices; lateral margins in apical half with large, acute serrations, the serrations much smaller between extreme apex and sutural margin; sutural margins moderately strongly raised in apical third; without costae or costate intervals; punctation in inner third very sparse, uniformly distributed, consisting of small pin-prick punctures; punctation in outer two-thirds, dense to very dense, consisting of small round to ovate punctures, becoming larger and more ovate towards the lateral margin, where they partly form transverse series; moderately strongly microreticulate between the punctures.

Hypomeron: contiguously punctate with fairly large, very shallow, ovate punctures, the bottom of the punctures strongly microreticulate, glabrous.

Prosternum: with a narrow bead at the anterior margin; the anterior margin at the same level as the area behind; prosternal process moderately widening distally, longer than wide at its widest point, very densely punctate, with very small round punctures, which form an incipient groove near the lateral margin, strongly microreticulate between the punctures, glabrous.

Mesanepisternum: strongly microreticulate, with some large and small very shallow punctures present.

Central part of metaventrite and inner part of metacoxa very sparsely punctate with small weak mostly pin-prick punctures, glabrous; lateral parts of metaventrite and metacoxae contiguously punctate, with fairly large shallow ovate and lunate punctures; abdominal ventrites, densely to very densely punctate, with small lunate punctures in central-third; laterally with much larger, coalescent, lunate punctures, with very short, inconspicuous, silvery pubescence, most obvious on the lateral parts of the 1 st ventrite.

Apical ventrite ( Fig. 159 ): contiguously punctate with very large elongate, lunate punctures in lateral two-thirds, which partly coalesce to form grooves near the lateral margin, very densely punctured with smaller lunate punctures in central third; excision wide, slightly W shaped, rather deep, with a well developed flange, triangularly produced at centre; lateral spines well developed, slightly divergent.

Fore tibia: strongly curved, with a small setal brush at the apex on the anterior face, and a few small teeth on the ventral face in the apical half.

Mid tibia: moderately strongly curved, without teeth on the ventral face

Aedeagus ( Figs 182, 183 ): rather short and broad, the parameres rather abruptly narrowing before the apical setae bearing parts, which are only slightly widened; no spine like setae present; median lobe with a very slightly asymmetric acute apex, with small serrations along the lateral margins behind the apex.

Comments. This species differs from all others in the species group in its very short, stout aedeagus and in having serrations along the lateral margins of the median lobe of the aedeagus. The colour of the upperside is also unlike any other species in the group.

Etymology. This species is named after the predominately reddish violet colour of the elytra.

Bionomics. Adult collected at light in January. Host unknown.

Figures

FIGURES 123–129. 123 dorsal habitus M. rufoviolacea sp. n. (holotype ♁). Scale bar = 5.0 mm. 124–129 head: 124. M. confundo sp. n. (holotype ♀); 125. M. aurocincta Carter (J 1.5 mls N.W. of Mourangee, Q. BLC); 126. M. imitator sp. n. (J Cape Naturaliste, W.A. TMSHC); 127. M. breviantennatus sp. n. (holotype ♀); 128. M. suturalis Thomson (J Hay Point, Mackay, Q. SAMA); 129. M. dentata sp. n. (holotype ♁). Scale bars = 1.0 mm.

FIGURES 136–142. 136 head M. rufoviolacea sp. n. (holotype ♁). 137–142 apical ventrite: 137. M. confundo sp. n. (holotype ♀); 138. M. aurocincta Carter (J 1.5 mls N.W. of Mourangee, Q. BLC); 139. M. aurocincta Carter (♀ Mourangee Station, Q. TMSHC); 140. M. imitator sp. n. (J Cape Naturaliste, W.A. TMSHC); 141. M. imitator sp. n. (♀ paratype Port Peron, W.A. SAMA); 142. M. breviantennatus sp. n. (holotype ♀). Scale bars = 1.0 mm.

FIGURES 159–165. 159. apical ventrite M. rufoviolacea sp. n. (holotype J) Scale bar = 1.0 mm. 160–161 prosternal process: Scale bars = 1.0 mm. 160. M. confundo sp. n. (holotype ♀); 161. M. rufoviolacea sp. n. (holotype ♁). 162–165 aedeagus & apex of parameres: 162–163. M. aurocincta Carter (J 1.5 mls N.W. of Mourangee, Q. BLC); 164–165. M. imitator sp. n. (Cape Naturaliste, W.A. TMSHC). Scale bars of aedeagus = 1.0 mm; scale bars for apex of parameres = 0.5 mm.

FIGURES 182–183. aedeagus & apex of parameres: 182–183. M. rufoviolacea sp. n. (holotype). Scale bars of aedeagus = 1.0 mm; scale bars for apex of parameres = 0.5 mm.