Stilbocistela rostislavi, Novák, 2009

Novák, Vladimír, 2009, A review of the genus Stilbocistela (Coleoptera: Tenebrionidae: Alleculinae) with description of new species from Malaysia and Indonesia, Acta Entomologica Musei Nationalis Pragae 49 (2), pp. 783-794 : 792-794

Stilbocistela rostislavi sp. nov.

( Figs. 19–23 )

Type locality. Malaysia, Kelantan, between Kampong Raja and Gua Musang, N 4°63-88´E 101°45 -95´.

Type material. HOLOTYPE: J, white label ‘ MALAYSIA, KELANTAN / road between Kampong Raja / and Gua Musang, 1400-1700 m, / (Ladang Pandrak), 1.-28. / iv.2006 4°63-88´N; 101°45-95´E, / Čechovský Petr lgt.’ ( NMPC) . PARATYPES: 15 specimens, same data as holotype ( NMPC, VNPC). The types are provided with a printed red label: ‘ Stilbocistela rostislavi sp. nov. HOLOTYPUS [or PARATYPUS] V. Novák det. 2008’.

Description. Body small, oval, strongly vaulted ( Fig. 19 ). General colouration from pale to dark brown, slightly shiny, length 5.27–5.98 mm, width at elytral midlength 2.29–2.87 mm.

Male (holotype). Head ( Fig. 20 ) large, brown with pale brown clypeus, slightly shiny, anterior part before eyes with sparse, short light setation, setation of clypeus longer. Head without punctuation, posterior part behind eyes slightly rugose, anterior part and clypeus transversely rugose. Eyes large, dark, transverse, emarginate, distance between eyes distinctly longer than length of antennomere 3. Ocular index equal to 36.75. Head 0.91 mm wide, widest across eyes, approximately 0.51 times as wide as pronotal base; visible part of head 0.74 mm long.

Antenna ( Fig. 21 ) relatively long (2.58 mm), reaching 0.51 of body length, with short setation. Antennomeres 1–3 unicolorous pale brown, antennomeres 4–8 and 11 bicolorous, posterior third of antennomere 4, anterior third of antennomere 11 and narrow strip in base of antennomeres 5–8 pale brown, rest of antennomeres 5–8 and antennomeres 9 and 10 dark brown. Antennomeres 4–10 distinctly longer than antennomere 3, duller, distinctly serrate, with relatively shallow, large punctures. Antennomere 2 shortest, antennomere 3 distinctly longer than antennomere 2. Ratios of relative lengths of antennomeres 1–11 equal to 0.66: 0.51: 1.00: 1.25: 1.25: 1.39: 1.25: 1.49: 1.27: 1.21: 1.37. Length / maximum width ratios of antennomeres 1–9 equal to 1.34: 1.60: 2.44: 2.44: 2.43: 2.05: 2.03: 1.83: 1.91: 1.71: 1.55: 2.03.

Maxillary palpus unicolorous pale brown, slightly paler than anterior part of head, with microgranulation, shiny. Second maxillary palpomere longer than penultimate palpomere, penultimate palpomere shortest, both distinctly broadest at apex, ultimate palpomere longitudinally triangular, securiform. Ratios of relative lengths of palpomeres 2–4 equal to 1.73: 1.00: 2.47. Length / maximum width ratios of palpomeres 2–4 equal to 2.72: 1.30: 1.02.

Pronotum ( Fig. 20 ) dark brown with pale brown margins, slightly shiny, glabrous, without distinct punctuation, longest in the middle (length 0.92 mm) and widest at base (width 1.80 mm); pronotal index equal to 50.82. Borders almost complete, only in middle of anterior and posterior margin indistinct; posterior margin bisinuate. Posterior angles slightly obtuse, lateral margins straight in posterior half and slightly rounded anteriorly.Anterior angles conspicuous, distinctly obtuse, rounded. Surface with microgranulation, only slightly shiny.

Elytra pale brown in colour, oval, glabrous, with microgranulation, duller and only slightly shiny, 3.39 mm long and 2.43 mm wide, slightly broader than pronotum, widest approximately at midlength. Elytral length / maximum width ratio equal to 1.39. Strial punctures conspicuous, separated by less than one diameter. Punctuation of elytral intervals indistinct. Epipleura well developed, pale brown, concolorous with elytra, narrowing in posterior half, in apical half before abdominal ventrite 5 parallel, then narrowing to rounded apex.

Scutellum large and broad, triangular, glabrous, pale brown, concolorous with elytra.

Legs unicolorous pale brown, tarsi with dense pale brown setation. Femora thicker than tibiae. Tibiae very narrow, slightly dilated at apex. Femora and tibiae with sparse, short, strong, dark brown setae. Tarsomeres of all tarsi narrow. Anterior and middle tarsomeres 3 and 4 and posterior tarsomeres 3 lobed. Ratios of relative lengths of tarsomeres 1–5 and 1–4 equal to 1.00: 0.47: 0.46: 0.65: 1.58 (protarsus), 1.00: 0.35: 0.31: 0.41: 1.06 (mesotarsus), and 1.00: 0.28: 0.24: 0.63 (metatarsus). Both anterior tarsal claws with 3 teeth.

Ventral side of body brown. Abdominal ventrites glabrous, coloured as dorsal part of body, with microgranulation, matt.

Aedeagus ( Figs. 22–23 ) pale yellowish brown. Basal piece 6.22 times as long as apical piece, feebly rounded in lateral view. Basal half of basal piece more than twice as wide as its apex in dorsal view. Apical piece almost regularly narrowing to rounded apex in both dorsal and lateral view.

Female. Habitus similar to male. Length 5.80 mm; length of head 0.77 mm; width of head 0.96 mm. Ocular index equal to 37.47. Pronotal length (along midline) 0.89; pronotal width at base 1.87 mm. Pronotal index equal to 47.66. Elytral length 4.14 mm; elytral width 2.87 mm.

Ratios of relative lengths of antennomeres 1–11 equal to 0.76: 0.45: 1.00: 1.08: 1.00: 1.09: 1.19: 1.23: 1.12: 1.13: 1.16. Length / maximum width ratios of antennomeres 1–11 equal to 1.58: 1.11: 2.61: 2.11: 1.54: 1.50: 1.67: 1.63: 1.57: 1.65: 1.67.

Ratios of relative lengths of tarsomeres 1–5 and 1–4 equal to 1.00: 0.52: 0.72: 0.98: 2.15 (protarsus), 1.00: 0.33: 0.39: 0.47: 1.08 (mesotarsus), and 1.00: 0.33: 0.32: 0.70 (metatarsus).

Variability. The type specimens (n = 16) vary somewhat in size (each character given as its mean value with full range in parentheses): body length 5.49 mm (5.27–5.98 mm); head length 0.86 mm (0.77–1.00 mm); head width 1.03 mm (0.95–1.13 mm). Ocular index 33.57 (28.46–39.24). Pronotal length (along midline) 0.94 mm (0.82–1.07 mm); pronotal width at base 2.00 mm (1.80–2.18 mm). Pronotal index 47.25 (44.10–49.51). Elytral length 3.69 mm (3.33–4.14 mm); elytral width 2.57 mm (2.29–2.87 mm).

Differential diagnosis. Stilbocistela rostislavi sp. nov. differs from the similar S. malaica sp. nov. mainly by the length of antennomere 3, which is shorter than each of antennomeres 4–10 (while antennomere 3 longer in S. malaica sp. nov.). It differs from S. manoiensis mainly by antennomere 3 almost twice as long as antennomere 2 (only slightly longer in S. manoiensis ). Finally, S. rostislavi sp. nov. differs from S. jelineki sp. nov. mainly by the distance between eyes distinctly longer than antennomere 3 and from S. luzonica mainly by having the dorsal surface of body matt and elytral intervals indistinctly punctate. For further details see the key above.

Etymology. This species is dedicated to my first grandson Rostislav.

Distribution. Peninsular Malaysia.

Figures

Figs. 19–23. Stilbocistela rostislavi sp. nov. (male holotype): 19 – habitus; 20 – head and pronotum; 21 – antenna; 22 – aedeagus, lateral view; 23 – aedeagus, dorsal view.