Melobasis, Laporte & Gory 1837, Laporte & Gory, 1837

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 : 6-7

The melanura species group

This group consists of 12 species some of which show considerable variation but I have not been able on the basis of the material I have seen, to unambiguously define any geographic subspecies. The species of this group mostly occur in the peripheral subhumid and semiarid regions of Australia.

Most species if not all are associated with Acacia species, which are the larval hosts of at least some species.

Species of this group share many characters with those of the nervosa species group and the composition and definition of these two groups is problematic and possibly artificial. Unlike most species of the nervosa species group the mesanepisternum in this group is densely punctured with small variably shaped punctures and round setae bearing punctures are not very apparent although they may be present amongst the smaller variably shaped punctures (in the nervosa species group most species have part of the mesanepisternum unpunctured although sometimes microreticulate and large obvious shallow setae bearing punctures are normally present); the frontoclypeal excision is often narrower and deeper than in species of the nervosa species group ( Figs 17–30 ) and in most species the parameres of the aedeagus only have long sensory setae and lack the strong stout spine like setae seen in the nervosa species group (Figs 63, 65, 67, 73, 75, 77), ( M. costata , M. oculata , M. calama and M. melanura have small spine like setae (Figs 59, 61, 69, 71) and might be considered as part of a redefined nervosa species group).

Key to the melanura species group

1 Elytra blackish lilac with violet and green reflections, with apex, lateral margin broadly and the basal margin narrowly, coppery red; with a scutellary vitta in the basal fifth pinkish copper, a large humeral patch, an irregular median fascia and a tear shaped pre-apical macula all golden-green (Fig. 1) (male unknown)................................... M. incongruens sp. n.

- Elytra without contrastingly coloured markings............................................................. 2

2 Each elytron with two or three well defined costae (Figs 2, 3); prosternal process densely pubescent in male; aedeagus with small stout spines in addition to the normal long sensory setae (Figs 58–61); upperside brown bronze.................. 3

- Each elytron with at most one well defined costa, sometimes with traces of a second, or if second fairly well defined then upperside not brown bronze; prosternal process not densely pubescent in male..................................... 4

3 Punctures at centre of pronotum round or ovate (Fig. 2); clypeus with a narrow V shaped notch at centre (Fig. 19); vertex about one-third width of head across eyes when viewed from above (Fig. 2); shape less narrow............. M. costata Macleay

- Punctures at centre of pronotum mostly transverse ellipsoidal (Fig. 3); frontoclypeus with a broad, shallow V shaped excision (Fig. 20); vertex slightly narrower, often about one-quarter width of head across eyes when viewed from above (Fig. 3); shape more narrow............................................................................ M. oculata sp. n.

4 Upperside predominantly copper coloured (Fig. 4), underside golden green in male (female unknown); frontoclypeal excision a narrow V shaped notch ( Fig. 18 ); parameres of aedeagus narrowing from near their midlength (Fig. 62)................................................................................................... M. aureoviridis sp. n.

- Elytra bronze, greenish bronze or green; if parameres of aedeagus narrowing from near their midlength then frontoclypeal excision broad, shallow U or V shaped.................................................................... 5

5 Frontoclypeus broadly, moderately depressed at the centre, the excision moderately deep and broad (Fig. 21); aedeagus short and broad, with the median lobe gradually narrowed to the truncate apex (Figs 64–65); habitus (Fig. 5); S.W. Australia.......................................................................................... M. rothei Blackburn

- Clypeus not at all, or only weakly depressed on either side of the excision, which is narrower and deeper or broader and shallower than in M. rothei ; aedeagus different.............................................................. 6

6 Frontoclypeal excision broad, shallow, V shaped (Figs 22–24).................................................. 7

- Frontoclypeal excision narrower or deeper, V or U shaped (Figs 25–30).......................................... 9

7 Median lobe of aedeagus with an acutely pointed apex (Figs 66–67); habitus (Fig. 6); species from N.W. Australia.............................................................................................. M. cuspidata sp. n.

- Median lobe of aedeagus not acutely pointed at apex (Figs 68–77); species from Queensland ......................... 8

8 Dull-green species with more or less extensive reddish violet or coppery reflections, especially on the underside (Fig. 7); parameres of aedeagus abruptly narrowing in apical third, the median lobe widely truncated at apex (Figs 68, 69)................................................................................................. M. calama sp. n.

- Blackish-bronze species (Fig. 8); parameres of aedeagus gradually narrowing in apical half, the median lobe narrowly truncated at apex (Figs 70, 71)................................................................. M. melanura Kerremans

9 Frontoclypeal excision deep, narrow, U shaped (Fig. 25); prosternal process strongly and densely punctured; habitus (Fig. 9); species from C. Queensland (Brigalow Belt)..................................................... M. incisa sp. n.

- Frontoclypeal excision less deep or narrow (Figs 24, 26–30).................................................. 10

10 Head without any obvious pubescence; colour dull green, green or golden green (Fig. 10); frontoclypeal excision relatively broad, shallow, V shaped (somewhat variable) (Fig. 26); aedeagus with parameres narrowing from near midlength, median lobe narrowly truncate at apex (Figs 74, 75)...................................................... M. simplex Germar

- Head with at least sparse pubescence (sometimes partly abraded); colour brown bronze to blackish bronze; frontoclypeal excision usually narrower of variable depth; aedeagus with parameres narrowing anterior to the midlength and/or apex of median lobe rounded and slightly constricted just before apex (Figs 70, 71, 76, 77)................................ 11

11 Frontoclypeus with well developed clypeal peaks bordering the excision ( Fig. 27 ); punctation of elytra very uniform, without obvious costate interstriae (Fig. 11); species from inland N.S.W.................................... M. myallae Carter

- Frontoclypeus without or with less developed clypeal peaks bordering the excision (Figs. 24, 28–30); punctation of elytra less uniform, with indications of costate interstriae (Figs 8, 12, 13, 14);............................................. 12

12 Aedeagus with apical part of parameres with small stout spines in addition to the normal long sensory setae, median lobe not constricted just before the apex (Figs 70, 71); blackish-bronze species (Fig. 8); species from C. Queensland (Brigalow Belt)................................................................................. M. melanura Kerremans

- Aedeagus with apical part of parameres with only the normal long sensory setae, median lobe constricted just before apex (Figs 76, 77); brownish- or greenish-bronze species (Figs 12–14); species from W. Australia, S. Australia & N. Territory................................................................................................ M. adusta sp. n.

Figures

FIGURES 13–18. 13–14 dorsal habitus: 13. M. adusta sp. n. (J Carnac Island, W.A. SAMA); 14. M. adusta sp. n. (J Wurarga, W.A. ANIC); 15–16 pronotum: 15. M. adusta sp. n. (J Carnac Island, W.A. SAMA); 16. M. adusta sp. n. (J paratype Yunta, S.A. BLC); 17–18 head from front: 17. M. incongruens sp. n. (holotype ♀); 18. M. aureoviridis sp. n. (holotype ♁). Scale bars Figs 13–14 = 5.0 mm; Figs 15–18 = 1.0 mm.

FIGURES 27–32. 27–30 head from front: 27. M. myallae Carter (holotype ♀); 28. M. adusta sp. n. (J paratype 12 km N. Paynes Find. BLC); 29. M. adusta sp. n. (J Wurarga, W.A. ANIC); 30. M. adusta sp. n. (J Carnac Island, W.A. SAMA); 31–32 prosternal process: 31. M. incongruens sp. n. (holotype ♀); 32. M. costata Macleay (J Marmor, Q. BLC). Scale bars = 1.0 mm.