Baiocis, Browne, 1962

Beaver, Roger A., 2018, A review of the genus Baiocis Browne, 1962 (Coleoptera: Curculionidae: Platypodinae), with new species, new synonymy and a key to males, Zootaxa 4434 (3), pp. 481-501 : 492-493

Key to Baiocis Males

1 Elytra vase-shaped, constricted anterior to declivity ( Fig. 1 ), with an elongate posterolateral process extending ventrally at nearly a right angle to plane of elytra ( Figs 3, 4 ). Head as long as or longer than high. Eye oval with long axis parallel to body ( Fig. 2 ).............................................................................................. 2

- Elytra not obviously constricted anterior to declivity. Posterolateral process shorter and more broadly triangular, sometimes extending almost horizontally. Head rounded, higher than long. Eye round or almost so.............................. 3

2 Head about as long as high, not flattened; vertex separated from frons by a distinct, evenly curved carina, below which frons is impressed. Posterolateral process of elytron vertical ( Fig. 4 ). Posterior margins of ventrites 2‒4 not raised and thickened, and without teeth. 2.0‒ 2.2 mm long............................................................. anaticeps (Schedl)

- Head flattened, longer than high ( Fig. 2 ); frons very short without a carina separating it from vertex. Posterolateral process of elytron directed somewhat posteriorly ( Figs 3 , 18 ). Posterior margins of ventrites 2‒4 raised and thickened to form transverse ridges projecting as blunt teeth at the sides of the ridge. 2.4 mm long.............................. crassiventris n. sp.

3 First abdominal ventrite with a median process extending ventrally and posteriorly over base of second ventrite, and apically truncate, weakly bifid, or irregularly rounded................................................................ 4

- First abdominal ventrite without a median process, although posterior part may bear a small, median, triangular spine, or be raised to form a curved ridge............................................................................. 7

4 Frons and vertex angularly separated. Median process on first abdominal ventrite weakly bifid at apex. Posterolateral processes of elytra very long, the apical emargination U-shaped ( Fig. 29 ). Larger species, 3.3‒3.5 mm long... sumatranus n. sp.

- Frons rounded into vertex. Median process on first abdominal ventrite truncate or irregularly rounded apically. Posterolateral processes of elytra short. Smaller species, 2.5‒2.8 mm long.................................................... 5

5 Fifth abdominal ventrite with a median conical spine in apical half ( Fig. 20 ). Median process on first abdominal segment with posterior margin irregularly rounded, and bearing two pairs of minute denticles. 2.5‒2.6 mm long........... spicatus n. sp.

- Fifth abdominal ventrite without a spine or process. Median process on first abdominal segment not gibbous ventrally, truncate posteriorly........................................................................................... 6

6 Second ventrite with a pair of small, rounded protuberances, separated by about the width of the process on ventrite 1 ( Fig. 8 ). Elytra strongly emarginate at apex, the emargination broadly U-shaped with base of emargination almost straight ( Fig. 7 ). 2.5‒2.7 mm long......................................................................... incisus (Sampson)

- Second ventrite without protuberances. Elytral apex shallowly V-shaped ( Fig. 11 ). 2.8 mm long.......... inimicus (Schedl)

7 Second ventrite gibbous medially, with a strong, pointed, posteroventrally directed tooth at each end of the gibbosity ( Fig. 2 2 ), the teeth separated by about the width of a curved ridge extending across about one third of the posterior part of the first ventrite ( Fig. 9 ). 2.7‒2.8 mm long............................................................. spiniventris n. sp.

- Abdomen usually not or weakly gibbous; if gibbous, then without teeth on second ventrite........................... 8

8 Third abdominal ventrite with a small median triangular raised area near the posterior margin, its apex posterior, fourth ventrite with a larger median conical tooth ( Fig. 32 ). 2.8‒3.0 mm long.......................................... laosi n. sp.

- Third and fourth abdominal ventrites without raised area or tooth................................................ 9

9 Metanepisternum with a carina at the anterior margin of the metanepisternum and metaventrite depression. Elytral apex with emargination broadly, very shallowly U-shaped, with basal margin nearly straight ( Figs 10, 13 ). Posterior part of elytra weakly curved ventrally so that apex of apicolateral spines is usually visible from above.................................. 10

- Metanepisternum with one or two small tubercles or spines at the anterior margin of the metanepisternum and metaventrite depression. Elytral apex with emargination crescentic or shallowly V-shaped ( Fig. 11 ). Posterior part of elytra more strongly curved ventrally so that apex of apicolateral spines is visible only from sides, not from above........................ 12

10 Apex of elytral disc just above declivity and declivity matt except close to suture, with a row of small granules on each interstria, a larger granule at the end of interstriae 1 and 3 at top of declivity ( Fig. 10 ). 2.0‒ 2.4 mm long.... angustiformis (Schedl)

- Apex of elytral disc just above declivity shining, with only a few minute granules on interstriae, without larger granules on interstriae 1 and 3 at top of declivity ( Fig. 13 )............................................................. 11

11 Larger species, 2.7‒2.8 mm long. Posterolateral tooth of elytra directed more strongly ventrally, barely visible from above......................................................................................... nubilosus Roberts

- Smaller species, 1.9‒2.4 mm long. Posterolateral tooth of elytra directed less strongly ventrally, clearly visible from above....................................................................................... pernanulus (Schedl)

12 First ventrite with a small median triangular spine extending horizontally over base of second ventrite. Apicolateral tooth of elytra truncate when viewed from behind. Large species, 4.7 mm long............................. sublunaris (Schedl)

- First ventrite unarmed. Apicolateral tooth of elytra pointed when viewed from behind. Smaller species, not more than 3.0 mm long............................................................................................... 13

13 Frons very finely punctured, except close to epistoma. Upper rim of declivity weakly carinate laterally, the carina not extend- ing close to suture ( Fig. 5 ). Apicolateral tooth of elytra forming an almost equilateral triangle, making an angle of 60°‒70° at its tip when viewed from side ( Fig. 6 ). 2.3‒2.4 mm long....................................... perinimicus (Schedl) - Frons coarsely punctured, especially on lower half. Upper rim of declivity more strongly carinate, carina extending close to suture. Apicolateral tooth of elytra more acute making an angle of 30°‒40° when viewed from side ( Fig. 15 )............ 14

14 Apicolateral tooth of elytra short ( Fig. 13 ). Declivital sulcus narrower vertically relative to width across elytra (23: 4), about 5 times wider than deep. Second ventrite without a transverse ridge. 2.1‒2.5 mm long. Thailand to Sulawesi ... orientalis n. sp.

- Apicolateral tooth of elytra longer ( Fig 15 ). Declivital sulcus broader vertically relative to width across both elytra, about 4 times wider than deep (28: 7). Second ventrite sloping posteriorly at about 60° to the vertical from a humped transverse ridge running across the middle of the ventrite ( Fig. 15 ). 2.8‒2.9 mm long. Papua New Guinea only........... unispineus Roberts

Figures

FIGURES 1–9. Baiocis species males. 1‒3. B. crassiventris. 1, dorsal view; 2, lateral view head; 3, lateral view elytral apex. 4. B. anaticeps, lateral view elytral apex. 5‒6. B. perinimicus, elytral apex. 5, posterolateral view; 6, lateral view. 7‒8. B. incisus. 7, dorsal view elytral apex; 8, ventral view abdomen. 9. B. spiniventris, ventral view abdomen. Scale line = 1.0 mm (Fig. 1); 0.5 mm (Figs 2‒6, 9); 0.67 mm (Figs 7‒8).

FIGURES 18–25. Baiocis species. 18‒19. B.crassiventris. 18, male, lateral view (2.4 mm); 19, female, dorsal view (2.3 mm); 20‒21. B. spicatus male (2.5 mm): 20, lateral view; 21, dorsal view; 22‒23. B. spiniventris male (2.7 mm): 22, lateral view; 23, dorsal view; 24‒25. B. angustipennis female (2.5 mm): 24, lateral view; 25, dorsal view.

FIGURES 26–32. Baiocis species. 26‒27. B. orientalis dorsal view: 26, male (2.3 mm); 27, female (2.4 mm). 28. B. pernanulus male (2.3 mm), dorsal view. 29. B. sumatranus male (3.5 mm), dorsal view. 30‒32. B. laosi. 30, male (2.9 mm), dorsal view; 31, female (3.0 mm), dorsal view; 32, male abdomen, lateral view.

FIGURES 10–17. Baiocis species. 10. B. angustiformis, dorsal view male elytral apex. 11‒12. B. inimicus. 11, dorsal view male elytral apex; 12, lateral view male abdomen and elytral apex. 13. B. pernanulus, dorsal view male elytral apex. 14, 17. B. orientalis. 14, male elytral apex, posterior view; 17, male head, lateral view. 15. B. unispineus, lateral view male abdomen and elytral apex. 16. B. pernanulus, lateral view female head. Scale line = 0.67 mm (Figs 11‒12, 15); 0.5 mm (Figs 10, 13, 16‒17); 0.4 mm (Fig. 14)