Brachelytrium

Bílý, Svatopluk & Bellamy, Charles L., 2010, Supplement to the revision of the genus Brachelytrium Obenberger, 1923 (Coleoptera: Buprestidae: Buprestinae: Anthaxiini), Zootaxa 2721, pp. 15-27 : 24-26

Key to the subgenera and species of Brachelytrium

1. Pronotal sculpture homogenous, consisting of regularly rounded or polygonal cells, each usually with well-developed central grains ( Figs. 1–6 ); entire body black or dark bronze, matt, occasionally with coppery lustre or metallic; antennae serrate from third antennomere; elytra shortened, disc uneven; ventral surface very often with patches of white tomentum ........................................................................................... subgenus Brachelytrium Obenberger ... 2

- Pronotal sculpture finer, consisting of polygonal cells with indistinct central grains on disc and oblique, elongate cells or rugae laterally ( Figs. 7, 8 ); body more lustrous, blue, bicolorous (pronotum and elytra of different colours) or bronze, cupreous or violet-bronze with pronotum red or purple laterally; antennae serrate from fourth antennomere; elytra less shortened in proportion, regularly convex; only metepimera with white tomentum..................................... ........................................................................................................... subgenus Elytrobrachium Bílý & Bellamy ... 21

2. Slender, relatively elongate species; length 4.4–5.7 mm; pronotum only 1.4 times as wide as long, elytra 1.6 times as long as wide; frontovertex in both sexes with two deep, vertical grooves for antennae in repose; anterior portion of frons between grooves with short, white pubescence; aedeagus as in Fig. 17 ; body length 4.4–5.7 mm; South Africa, Zimbabwe......................................................................................................... B. (B.) fissifrons Bílý & Bellamy, 2000

- Shorter and more stout species; pronotum 1.5–1.8 times as wide as long, elytra 1.3–1.5 times as long as wide; head without grooves, frons with or without pubescence ..................................................................................................... 3

3. Frons with distinct white, off-white or grey pubescence.............................................................................................. 4

- Frons completely glabrous.......................................................................................................................................... 12

4. Frontal pubescence white; setae two to three times longer than diameter of frontal punctures; frons flat without basal microsculpture; male unknown; body length 5.6 mm; South Africa....... B. (B.) waterbergense Bílý & Bellamy, 2000

- Frontal pubescence off-white or grey; setae shorter, with length same as diameter of frontal punctures or shorter; frons flat or depressed with basal microsculpture......................................................................................................... 5

5. Smaller, slender species; elytra 1.6 times as long as wide; frons flat or with rather deep, rounded, medial depression; frontal cells always without central grains but with dense, basal microsculpture ........................................................ 6

- Larger, more robust species; elytra 1.3–1.5 times as long as wide; frons flat or with wide, shallow, postclypeal depression; pronotal sculpture rugose, with sharp central grains; frontal cells with or without central grains ........... 7

6. Smaller, more flattened species; frons with small but deep, rounded depression; pronotal sculpture finer with very small central grains; lateroposterior depressions well developed; frontal cells shallow but complete, rounded; male unknown; 4.0 mm; South Africa.................................................................... B. (B.) prolongum Bílý & Bellamy, 2000

- Larger, more convex species; frons flat; pronotal sculpture more rugose with sharp central grains; pronotum very convex without lateroposterior depressions; frontal cells very shallow, incomplete, nearly semicircular, open posteriorly; aedeagus as in Fig. 20 ; 4.7 mm; South Africa........................................ B. (B.) globicolle Bílý & Bellamy, 2000

7. Frons anteriorly with wide, shallow depression; anterior margin of frontoclypeus widely, arcuately emarginate ..... 8

- Frons flat; anterior margin of frontoclypeus straight; elytra 1.4 times as long as wide; more convex species ............ 9

8. Elytra only 1.3 times as long as wide; frontal depression shallow; ventral surface with white, tomentose patches; aedeagus as in Fig. 15 ; body length 4.1–6.1 mm; South Africa..................... B. (B.) straussae Bílý & Bellamy, 2000

- Elytra more parallel, 1.5 times as long as wide; frontal depression deep; ventral surface without tomentose patches; body length 5.2 mm; Kenya......................................................................................... B. (B.) purpureiventre sp. nov.

9. Pronotum as wide as elytra; abdomen shorter, elytra extending as far as opposite posterior angles of penultimate tergite ( Fig. 4 ) ............................................................................................................................................................. 10

- Pronotum distinctly wider than elytra; abdomen longer, elytra extending as far as opposite posterior angles of third visible tergite ( Fig. 2 ).................................................................................................................................................. 11

10. More robust; anterior margin of frontoclypeus emarginate; frontal pubescence longer (setae longer than diameter of cells); aedeagus as in Fig. 13 ; body length 5.0– 5.3 mm; South Africa............ B. (B.) transvalense Obenberger, 1923

- Less robust; anterior margin of frontoclypeus straight; frontal pubescence very short (setae shorter than diameter of cells); aedeagus as in Fig. 12 ; body length 5.0– 5.3 mm; Namibia.................................................. B. niehusi sp. nov.

11. Large, more robust, matt; central grains on pronotum large, flat; elytral sculpture rough; aedeagus as in Fig. 19 ; body length 5.3–6.7 mm; Tanzania....................................................................... B. (B.) tanzaniense Bílý & Bellamy, 2000

- Smaqller, slender, lustrous; central gains on pronotum small, sharp; elytral sculpture much finer .......................... 12

12. Frontal ocellation very fine and dense; pronotum 1.8 times as wide as long; pronotal ocellation wider, somewhat longitudinally prolonged along lateral margins; scutellum lustrous, as wide as long; tarsal claws slightly enlarged at base; male unknown; body length 4.3 mm; Mauritania.................................................. B. (B.) mauritanicum sp. nov.

- Frontal ocellation sparser, more rough; pronotum 1.5 times as wide as long; pronotal ocellation finer, homogenous; scutellum microsculptured, slightly longer than wide; tarsal claws not enlarged at base; aedeagus as in Fig. 11 ; body length 4.7–5.8 mm; Benin..................................................................................................... B. (B.) beninense sp. nov.

13. Frons deeply, widely excavated ................................................................................................................................ 14

- Frons flat or slightly grooved or depressed medially ............................................................................................... 16

14. More robust species; pronotal sculpture on disc finer, with flat central grains; elytra 1.5 times as long as wide ..... 15

- Less robust species; pronotal sculpture on disc more rugose with small but sharp central grains; elytra 1.4 times as long as wide; frons of female bronze, male unknown; body length 4.8 mm; Namibia................................................. ................................................................................................................................... B. (B.) cavifrons Bílý & Bellamy

15. Entire body bronze; frons of male green with large, dark violet medial spot, those of female dark purple with narrow, golden green vitta along inner margins of eyes; antennae hardly reaching midlength of lateral pronotal margins; maximum pronotal width at midlength; meso- and metatibiae not enlarged posteriorly; aedeagus as in Fig. 14 ; body length 5.3–5.4 mm; Moçambique, South Africa................................................................ B. (B.) lesnei ( Théry, 1934)

- Dorsal surface dark green, ventral surface blue-green; antennae slightly overlapping midlength of lateral pronotal margins; maximum pronotal width at anterior third; meso- and metatibiae slightly enlarged posteriorly; male unknown; body length 5.8 mm; South Africa........................................................................... B. (B.) aeneum sp. nov.

16. Small, slender species; frons flat with small, deep, rounded, medial depression; entire body including frons black with slight coppery lustre; male unknown; body length 3.2 mm; Lesotho, South Africa, Zimbabwe........................... ........................................................................................................................... B. (B.) minusculum Obenberger, 1928

- Larger, more robust species; frons flat, or slightly grooved medially, very rarely with small, rounded depression; colouration of frons purple or golden-green ............................................................................................................... 17

17. Short, robust species with nearly cordiform pronotum; elytra only 1.3 times as long as wide; pronotum with deep lateroposterior depressions; body dark bronze, frons and antennae dark purple, posterior pronotal angles and elytral base feebly reddish; male unknown; body length 4.2–4.4 mm; Botswana... B. (B.) cordinotum Bílý & Bellamy, 2000

- Relatively slender species; elytra 1.4 times as long as wide; pronotum widely rounded laterally, widest just posteriad of mid-point but not cordiform; lateroposterior pronotal depressions small, shallow; body dark bronze or red-bronze, frons golden-green, purple or bronze with reddish tint .............................................................................................. 18

18. Frons slightly concave, bright purple in female, golden-green in male; body reddish bronze; pronotal sculpture with wide but flat central grains; aedeagus as in Fig. 18 ; body length 4.1–5.0 mm; Namibia............................................... ..................................................................................................................... B. (B.) namibiense Bílý & Bellamy, 2000

- Frons flat, bright purple or bronze with golden-green angles and clypeus in male, dark bronze with slight red tint in female; pronotal sculpture with small but sharp central grains .................................................................................. 19

19. Frontal sculpture consisting of large, rounded and very dense cells, each separated by very narrow interstitial carina .................................................................................................................................................................................... 20

- Frontal sculpture consisting of smaller, rounded cells, separating interstitial carina equal to half cell diameter; frons of male bronze with golden-green anterior angles and clypeus, of female bronze; ventral surface bronze in both sexes; aedeagus as in Fig. 16 ; body length 4.0– 6.1 mm; South Africa................. B. (B.) holmi Bílý & Bellamy, 2000

20. Dorsal surface bronze; frons of male bright purple, that of female bronze; pronotal ocellation with well-developed central grains; scutellum as wide as long; aedeagus as in Fig. 10 ; body length 4.6–5.2 mm; South Africa................. .................................................................................................................................. B. (B.) africanum ( Pochon, 1972)

- Entire body black; pronotal ocellation with indistinct central grains; scutellum1.2 times as long as wide; aedeagus as in Fig. 9 ; body length 5.6 mm; Kenya....................................................................................... B. (B.) nigrum sp. nov.

21. Smaller (2.5–4.5 mm); pronotum without lateroposterior depressions; lateral portion of pronotum with oblique, elongate cells.............................................................................................................................................................. 22

- Larger (4.2–5.7 mm), more robust species; pronotum with well-developed lateroposterior depressions; lateral portion of pronotum with elongate, oblique rugae .......................................................................................................... 24

22. Entire body bronze; frons nearly flat; body length 2.5–3.5 mm; Yemen........................ B. (E.) yemeni Brechtel, 2000

- Blue to blue-violet or bicolorous species; frons widely, rather deeply impressed ..................................................... 23

23. Distinctly bicolorous: elytra blue or blue-green, pronotum golden-orange or golden-red with large, subtriangular black spot reaching almost scutellum; frons golden green in male, dark blue in female; lateral portion of abdominal ventrites golden in male, purple in female; elytral sculpture very fine; anal ventrite shortly truncate; aedeagus as in Fig. 21 ; body length 3.1–4.5 mm; Namibia, South Africa, Zimbabwe........................ B. (E.) blairi Obenberger, 1931

- Elytra blue-violet; frons, pronotum and scutellum blue; ventral surface black with blue tinge; elytral sculpture more rough; anal ventrite widely rounded; body length 3.8 mm; Zambia..................................... B. (E.) caeruleum sp. nov.

24. Dorsal surface dark bronze, anterior pronotal angles and lateral portions with reddish lustre (male) or dark purple (female); frons bright (male) or dark (female) purple; ventral surface black, lateral portions of ventrites bronze (male) or red (female); lateroposterior pronotal depressions shallow; pronotal ocellation with well-developed central grains; aedeagus as in Fig. 23 ; body length 4.2–5.7 mm; South Africa.................. B. (E) ventrale ( Kerremans, 1911)

- Dorsal surface golden green (male) or blue (female), pronotal disc somewhat darkened; ventral surface golden green with blue tinge (male) or blue-green (female); lateroposterior pronotal depressions rather deep; pronotal ocellation with small, indistinct central grains; aedeagus as in Fig. 22 ; body length 4.2–5.3 mm; Kenya, Zimbabwe................. ............................................................................................................................................. B. (E.) metallicum sp. nov.

Figures

FIGURES 1 – 8. 1 – 6, dorsal habitus of six new species of Brachelytrium (Brachelytrium): Fig. 1, B. nigrum sp. nov., holotype, 5.6 mm (maximum length); Fig. 2, B. mauritanicum sp. nov., holotype, 4.3 mm; Fig. 3, B. beninense sp. nov., holotype, 4.7 mm; Fig. 4, B. niehuisi sp. nov., holotype, 5.0 mm; Fig. 5, B. purpureiventre; sp. nov., holotype, 5.2 mm; Fig. 6, B. aeneum sp. nov., holotype, 5.8 mm; and Figures 6, 7, dorsal habitus of two new species of Brachelytrium (Elytrobrachium): Fig. 7, B. caeruleum sp. nov., holotype, 3.8 mm; Fig. 8, B. metallicum sp. nov., holotype, 4.6 mm.

FIGURES 9 – 23. 9 – 20, dorsal aspect of male genitalia of Brachelytrium (Brachelytrium): Fig. 9, B. nigrum, sp. nov.; Fig. 10, B. africanum (Pochon, 1972); Fig. 11, B. beninense, sp. nov.; Fig. 12, B. niehuisi, sp. nov.; Fig. 13, B. transvalense Obenberger, 1923; Fig. 14, B. lesnei Bílý & Bellamy, 2000; Fig. 15, B. straussae Bílý & Bellamy, 2000; Fig. 16, B. holmi Bílý & Bellamy, 2000; Fig. 17, B. fissifrons Bílý & Bellamy, 2000; Fig. 18, B. namibiense Bílý & Bellamy, 2000; Fig. 19, B. tanzaniense Bílý & Bellamy, 2000; Fig. 20, B. gibbicolle Bílý & Bellamy, 2000; and Figures 21 – 23 of Brachelytrium (Elytrobrachium): Fig. 21, B. blairi (Obenberger, 1931); Fig. 22, B. metallicum, sp. nov.; Fig. 23, B. ventrale (Kerremans, 1911). Figures 10, 13 – 21, 23 are those used in Bílý & Bellamy (2000) where no scale bars were used. The scale bars for Figs. 9, 11, 12 and 22 = 1.0 mm and are approximately to scale for the remaining figures, all drawn by the senior author from the same magnification originally, with slight scale adjustments in the creation of this plate. Figures 9 – 20 are to the scale of 9, 11 and 12, while Figures 21 and 23 are to the scale of 22.