Melobasis breviantennatus, 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 : 69-70

M. breviantennatus sp. n.

( Figs 114 , 127 , 142 )

Type locality: Queensland, 30 km W. of Alpha .

Type specimens examined. Holotype ♀ (Q MA) 30 km W. of Alpha, Qld.T.M.S. Hanlon, Ex. dead standing Acacia leiocalyx / Coll. 28 August 1999. Emerged Jan. 2000.

Diagnosis. Only ♀ known. General diagnosis: length 5.6 mm; upper two-thirds of head dull violet with green reflections, lower third reddish purple; pronotum predominantly bluish violet in central three quarters with greenish reflections laterally in apical half; lateral margins broadly purple to reddish purple, becoming brighter reddish purple in basal half, this colour extending over the lateral half of the pronotum in basal third; scutellum blue-green; elytra with basal sixth of elytra blue-green, contiguous with a similar coloured, broad, elongate vitta extending over the humeral callosity, along the lateral margin and epipleura to level of the first ventrite, where it gradually narrows, before terminating at about the apical fifth of the elytra; remainder of elytra reddish purple with coppery reflections on disc; underside predominantly deep lilac, prosternum, prosternal process, mesosternum and mesanepisternum reddish purple; underside sparsely clothed with short silvery pubescence, central part of the prosternum, prosternal process, mesosternum, central parts of metaventrite glabrous.

Head ( Fig. 127 ): very densely punctate with small, round and ovate punctures; densely clothed with short silvery inconspicuous pubescence; spaces between the punctures very weakly microreticulate;; clypeal excision shallow, arcuate, with a broad truncate lobe at the middle, with a narrow, complete impunctate border; clypeal peaks obtusely angled; clypeal angles scarcely indicated; vertex slightly convex, about half width of head across eyes when viewed from above; eyes strongly convex.

Antenna: very short; segments 4–10 expanded, segment 4 with expansion almost triangular, about as long as wide, segments 5–10 with expansion almost quadrate, slightly petiolate, progressively shorter and smaller, slightly wider than long; segment 11 very small, nearly ovoid.

Pronotum: 1.53 × as wide at base as long in midline; anterior margin weakly bisinuate with a slightly developed, broad, median lobe, with a narrow entire beaded margin; posterior margin weakly biangulate; wides just posterior to midlength; lateral margins straight for a very short distance in front of basal angles, then weakly diverging to widest point, before curvilinearly converging to apical angles; basal angles slightly acute; almost as wide at base as elytra at base; lateral carina sharp, well defined, slightly sinuate, about three-quarters complete; punctation in central fifth sparse, consisting of very small round to ovate punctures; punctation in lateral four-fifths dense to contiguous, the punctures in anterior inner half large, very shallow, partly obscured by the strong microreticulation, forming a contiguous meshwork; on the rest of the pronotum punctures, dense to very dense, smaller, deeper, ovate and round; spaces between punctures strongly microreticulate; glabrous.

Scutellum: almost obovate, about one-fifteenth width of elytra at base; weakly microreticulate.

Elytra: 1.88 × as long as wide at base; basal margin moderately strongly biangulate, slightly widening from base over the humeral callosities thence very slightly widening to midlength, before narrowing to the rather broadly rounded apices; lateral margins in apical half, and apices serrate, with acute serrations; sutural margins moderately strongly raised in apical third; without costae or costate intervals; punctation in inner half mostly sparse, consisting of pin-prick and small round punctures; punctation in outer half very dense to contiguous, consisting of much larger transversely ovate punctures, partly forming transverse series near the lateral margin; weakly microreticulate between the punctures.

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

Prosternum: with a broad bead at the anterior margin; the anterior margin at about the same level as the area behind; prosternal process moderately strongly widening distally, almost as wide as long at its widest point, densely punctate, with small ovate punctures, glabrous.

Mesanepisternum: microreticulate, punctate with numerous small variably shaped punctures.

Central part of metaventrite and inner quarter of metacoxa sparsely punctate with small weak mostly pin-prick punctures; lateral parts of metaventrite and metacoxae very densely to contiguously punctate, with fairly large shallow ovate punctures; abdominal ventrites very sparsely clothed with short silvery pubescence, and sparsely, to moderately densely, weakly punctate, with small lunate punctures in central-third; laterally with larger, coalescent, lunate punctures, with moderately short silvery pubescence.

Apical ventrite ( Fig. 142 ): contiguously punctate with slightly elongate, lunate punctures over most of the surface; excision U shaped with a broad straight flange, occupying two-thirds of the depth of the excision.

Fore tibia: very slightly curved, with a very small setal brush at the apex on the anterior face.

Mid tibia: almost straight, unmodified.

Ovipositor: short, almost as wide as long.

Comments. This species is most similar to M. dentata sp. n. based on the external characters of the only known female, but is easily distinguished by its very short antennae, with very short, broad, distal segments, the form of the flange of the apical ventrite (compare Figs 142 & 146 ) and the different sculpture of the mesanepisternum.

Etymology. This species is named for the very short antennae, especially in comparison to M. dentata sp. n.

Bionomics. Larval host Acacia leiocalyx .

Figures

FIGURES 111–114. dorsal habitus: 111. M. confundo sp. n. (holotype ♀); 112. M. aurocincta Carter (♀ Mourangee Station, Q. TMSHC); 113. M. imitator sp. n. (♀ paratype Port Peron, W.A. SAMA); 114. M. breviantennatus sp. n. (holotype ♀). Scale bars = 5.0 mm.

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 143–150. apical ventrite: 143. M.suturalis Thomson (J Hay Point, Mackay, Q. SAMA); 144. M.suturalis Thomson (♀ Cairns, Q. SAMA); 145. M. dentata sp. n. (holotype J); 146. M. dentata sp. n. (♀ paratype Glencoe, Q. BLC); 147. M. tricolor sp. n. (J paratype Broome, W.A. MVMA); 148. M. tricolor sp. n. (♀ paratype Broome, W.A. BLC); 149. M. adamsi sp. n. (holotype J); 150. M. adamsi sp. n. (♀ Edungalba, Q. BLC). Scale bars = 1.0 mm.