Melobasis formosa, Carter B. Levey, 1923

Levey, Brian, 2012, 3464, Zootaxa 3464, pp. 1-107 : 24-26

Key to the formosa species-group

1 Lunate punctures of apical sternite usually well separated over most of the surface, if contiguous then the punctures are linked to form transverse series ( Figs. 6, 7)...................................................................... 20

- Lunate punctures of apical sternite often contiguous over most of the sternite ( Fig. 8), if contiguous punctures are confined to the region of the lateral margin, then the punctures are linked to form series more or less parallel to the lateral margin ( Fig. 9) ................................................................................................... 2

2 Lunate punctures of apical sternite contiguous over most of the sternite, sometimes forming concentric semicircular grooves, or grooves turning inwards towards the midline distally ( Fig. 8)................................................. 3

- Lunate punctures of apical sternite forming linked series more or less parallel to the lateral margin ( Fig. 9).............. 8

3 Punctation of prosternum and prosternal process dense or very dense, the punctures separated by less than half their own diameter; aedeagus ( Fig. 179)............................................................... M. amoena sp. n.

- Punctation of prosternum and prosternal process sparse to moderately dense, most punctures separated by more than their own diameter 4

4 Elytra yellow-bronze with the apices and sometimes the sutural and lateral margins in the apical half reddish-purple, without contrasting vittae, fasciae or maculae...................................................................... 5

- Elytral ground colour variable, always with at least a slightly developed humeral vitta and median macula or fascia, and often with a pre-apical macula 6

5 Pronotum widest at the posterior angles (Fig. 98); aedeagus short ( Fig. 166)........................... M. brevis sp. n.

- Pronotum widest at or near the mid-length (Fig. 99); aedeagus elongate ( Fig. 168)................. M. marlooensis Carter

6 Elytra yellow-bronze or brownish-copper with blue or violet markings; median fascia strongly constricted or divided to form two maculae (Figs. 104, 105); aedeagus almost parallel sided in apical half ( Fig. 167) M. dividua sp. n.

- Elytra reddish-purple, purple-brown or rarely golden-copper, with green, golden or coppery markings; median fascia not divided, but sometimes reduced (Figs. 100, 101, 102, 103); aedeagus not parallel sided in apical half ( Figs. 164, 165) 7

7 Pronotum with lateral margins straight or divergent to the posterior angles for some distance in front of the posterior angles; prosternum without a bead at least at the central part of the anterior margin; excision of apical sternite in female with lateral spines ( Fig. 201); aedeagus ( Fig. 164)......................................................... M. burnsi sp. n.

- Pronotum with lateral margins convergent to the posterior angles for some distance in front of the posterior angles (sometimes parallel sided or slightly divergent immediately in front of posterior angles); prosternum with a complete sometimes very narrow bead at the anterior margin; excision of apical sternite in female without lateral spines ( Fig. 215); aedeagus ( Fig. 165)...................................................................................... M. formosa Carter

8 Elytra with a humeral vitta, sutural vitta and often a median fascia and pre-apical macula; sometimes these markings may be partly fused.......................................................................................... 9 - Elytra with only the apex and the lateral and sutural margins contrasting in colour to the rest of the elytra.............. 27

9 Elytral markings yellowish-copper, enlarged, the humeral vitta closely approaching and sometimes joined to the median fascia, which is sometimes joined to the pre-apical macula and the sutural vitta; ground colour violet or blue (Fig. 112)........... M. flavoaenea sp. n.

- Elytral markings and ground colour different.............................................................. 10

10 Prosternal process with a line of contiguous punctures close to the lateral margin extending almost to the apex of the process ( Fig. 27); elytral markings green or golden................................................................. 30

- Prosternal process with or without a line of contiguous punctures close to the lateral margin, if with a line of contiguous punctures extending almost to the apex of the process, then elytral markings silvery-blue.......................... 11

11 Prosternal process without a groove or line of coalescent punctures near the lateral margin........................... 12

- Prosternal process with a groove or line of coalescent punctures near the lateral margin, at least at the base ( Figs. 26, 27).. 16

12 Elytral markings green, golden or pinkish-copper........................................................... 14

- Elytral markings silvery-blue.......................................................................... 13

13 Parameres of aedeagus not strongly constricted before the apical setae-bearing part ( Fig. 172); form slender ; the lateral margins of the elytra usually strongly sinuate before the apex (Fig. 107); elytra without a marked dorso-ventral flexure..................................................................................... M. septemplagiata Carter

- Parameres of aedeagus strongly constricted before the apical setae-bearing part ( Fig. 170); form less slender; the lateral margins of elytra not strongly sinuate before the apex, or elytra with a marked dorso-ventral flexure (Figs. 119, 148)................................................................................................. M. flexa sp. n.

14 Prosternum without a bead at least at the central part of the anterior margin............................ M. burnsi sp. n.

- Prosternum with a complete narrow bead at the anterior margin................................................ 15

15 Humeral vitta long, as long or longer than the sutural vitta (Fig. 108); aedeagus more elongate, the median lobe produced at the apex ( Fig. 171)......................................................................... M. acutula sp. n.

- Humeral vitta short, shorter than the sutural vitta (Fig. 102, 103); aedeagus less elongate, the median lobe not produced at the apex ( Fig. 165)......................................................................... M. formosa Carter

16 Elytral markings coppery, golden or green................................................................ 17

- Elytral markings silvery-blue or pinkish.................................................................. 18

17 Pre-apical macula of elytra very large, much longer than the humeral vitta (Fig. 113); pubescence of lateral half of pronotum long and obvious (except when abraded); punctures close to lateral margin of apical sternite coalescing to form well marked elongate grooves parallel to the margin...................................................... M. knowlesi sp. n.

- Pre-apical macula of elytra smaller, as long or shorter than the humeral vitta (Fig. 111); pubescence of lateral half of pronotum shorter and less obvious; punctures close to lateral margin of apical sternite partly coalescent, but not forming well defined grooves parallel to the margin.............................................................. M. goerlingi sp. n.

18 Parameres of aedeagus strongly constricted before the apical setae-bearing part ( Fig. 170); elytra often with a marked dorsoventral flexure ( Fig. 148); robust species, length 12–17 mm ......................................... M. flexa sp. n.

- Parameres of aedeagus not strongly constricted before the apical setae-bearing part ( Figs. 169, 172); elytra without a marked dorso-ventral flexure; less robust species, length 9–13 mm .................................................... 19

19 Aedeagus elongate, with a marked longitudinal ventro-dorsal flexure ( Fig. 169); pronotum with sides more rounded, usually not as wide at posterior angles as at mid-length (Fig. 106)......................................... M. brittoni sp. n.

- Aedeagus less elongate, without a marked longitudinal ventro-dorsal flexure ( Fig. 172); pronotum with sides less rounded, usually almost as wide at posterior angles as at mid-length (Fig. 107)........................ M. septemplagiata Carter

20 Elytra without vittae or fasciae.......................................................................... 21

- Elytra with vittae and fasciae........................................................................... 22

21 Pronotum more transverse, with a broad unpunctured anterior border; prosternal process with a groove formed from coalescent punctures, well separated from the lateral edge; centre of prosternum and prosternal process densely pubescent; sutural margins of elytra well separated at apex (Fig. 116) M. meyricki Blackburn

- Pronotum less transverse, with a narrow unpunctured anterior border; prosternal process with a line of coalescent punctures close to the lateral edge; centre of prosternum and prosternal process only sparsely pubescent; sutural margins of elytra only slightly separated at apex (Fig. 117) M. nudipectus sp. n.

22 Elytra with an elongate vitta internal to the humeral callosity; pronotum unicolourous brown-bronze, greenish-bronze, steelblue or grey, sometimes with a violaceous reflection; not sexually dichromic...................................... 23

- Elytra with a humeral macula; sexually dichromic: female with underside, head and lateral half of pronotum, reddish-purple; centre of pronotum yellow- or greenish-bronze, with the midline and the junction of the lateral and central areas, narrowly steel-blue: male with underside, head, lateral half and midline of pronotum bright green, remainder of pronotum reddish-purple or violet......................................................................... obscurella species-group

23 Sutural vitta very long, extending from the scutellum to about half elytral length; humeral vitta long almost reaching and sometimes narrowly joined to the median fascia; pre-apical macula very elongate and almost reaching apex of the elytra, and sometimes almost joined to the median fascia (Fig. 115) M. hanloni sp. n.

- Sutural vitta not more than one-quarter the length of the elytra; humeral vitta and pre-apical macula less elongate, well separated from the median fascia 24

24 Pronotum largely brown- or greenish-bronze; elytra usually with indications of three costae at the mid-length; mid tibia of male curved and slightly swollen, with a depression on the ventral face; aedeagus with lateral margin of parameres strongly sinuate in the apical half, the apex with small stout setae in addition to the normal fine setae ( Fig. 188)....................................................................................... M. similis sp. n. gloriosa species-group - Pronotum mainly steel-blue or grey, sometimes with a violaceous reflection; elytra usually with indications of only two costae at the mid-length; mid tibia of male straight, not swollen and without a depression on the ventral face; aedeagus with lateral margin of parameres less strongly sinuate in the apical half, the apex with fine setae only ( Figs. 169, 173, 175)......... 25

25 Elytral markings coppery, golden or green, the elytral ground colour bluish-violet or bright reddish-violet (Figs. 109, 110)... ................................................................................................... 26

- Elytral marking silvery-blue, silvery-green or rarely pinkish-copper, the elytral ground colour brownish-copper to dull reddishviolet (Fig. 106); aedeagus ( Fig. 169)........................................................ M. brittoni sp. n.

26 Pronotum less transverse, 1.37–1.50 times as wide at base as long in midline; basal margin of elytra weakly bisinuate (Fig. 110); aedeagus fairly short, the parameres strongly constricted near the base and just before the apical setae-bearing part ( Fig. 173)..................................................................................... M. janae sp. n.

- Pronotum more transverse, 1.56–1.73 times as wide at base as long in midline; basal margin of elytra strongly bisinuate (Fig. 109); aedeagus elongate, the parameres not strongly constricted near the base or before the apical setae-bearing part ( Fig. 175)....................................................................................... M. powelli sp. n.

27 Basal margin of elytra almost straight or slightly bisinuate; pronotum reddish-violet to lilac laterally, brown- or greenishbronze at centre, with the midline and the junction of the lateral and central areas, often blue-green or blue (Fig. 118)........................................................................................... M. purpurilata sp. n.

- Basal margin of elytra strongly biarcuate or biangulate; pronotum unicoloured, blackish-bronze or coppery with reddish-purple reflections 28

28 Prosternal process strongly and abruptly widening behind the fore coxae, without a line of enlarged or coalescent punctures near the lateral margin ( Fig. 153); excision of apical sternite about three times as wide as deep ( Fig. 9) M. caudata Carter

- Prosternal process only slightly, gradually widening behind the fore coxae, with a line of enlarged or coalescent punctures near the lateral margin ( Fig 154); excision of apical sternite one to one and half times as wide as deep..................... 29

29 Elytral apices, lateral margin and sutural margin in apical three-quarters, an elongate patch over the humeral callosity and an elongate patch internal to the 1 st costate interval, all violet or blue............................... M. flavoaenea sp. n.

- At most only tips of elytra reddish-purple or violet....................................... M. septemplagiata Carter

30 Vertex slightly wider, about two-thirds width of head across eyes when viewed from above; pronotum rather transverse, 1.51–1.66 times as wide at base as long in midline; basal margin of elytra strongly bisinuate (Fig. 111); aedeagus ( Fig. 174)........................................................................................ M. goerlingi sp. n.

- Vertex slightly narrower, about three-fifths or less width of head across eyes when viewed from above................. 31

31 Pronotum less transverse, 1.37–1.50 times as wide at base as long in midline; basal margin of elytra weakly bisinuate (Fig. 110); aedeagus fairly short, the parameres strongly constricted near the base and just before the apical setae-bearing part ( Fig. 173)..................................................................................... M. janae sp. n.

- Pronotum more transverse, 1.56–1.73 times as wide at base as long in midline; basal margin of elytra strongly bisinuate (Fig. 109); aedeagus elongate, the parameres not strongly constricted near the base or before the apical setae-bearing part ( Fig. 175)....................................................................................... M. powelli sp. n.