Peltonotus deltamentum Jameson and Wada, 2004

Jameson, Mary Liz & Wada, Kaoru, 2004, Revision of the genus Peltonotus Burmeister (Coleoptera: Scarabaeidae: Dynastinae) from Southeastern Asia, Zootaxa 502 (1), pp. 1-66 : 18-19

Peltonotus deltamentum Jameson and Wada , n. sp.

( Figs. 19 , 29 , 33 , 39a–c , 67)

Type Material. Holotype male housed at WADA with following label data, male genitalia and mouthparts mounted beneath specimen: a) " Balai Karangan Kalimantan Barat Borneo INDONESIA X 1989 leg. N. Nisikawa " (typeface), b) K. WADA Col. No. 336" (typeface, yellow label), c) our holotype label.

Description. Holotype male. Length 16.6 mm. Widest width 8.0 mm. Color: Head, pronotum, scutellum, pygidium, elytron, and venter castaneous. Elytra with weak iridescent bloom Head: Surface of frons with base sparsely punctate, disc densely punctate; punctures simple, lacking setae or setigerous laterally; setae minute (1–7 per puncture) and short (0–1 per puncture). Surface of clypeus densely punctate; punctures simple, lacking setae or setigerous laterally; setae minute (1–7 per puncture) and short (0–1 per puncture). Clypeus laterally weakly bowed, apex truncate, corners square, beaded; bead not weakly arcuate posteriorly. Labrum broadly narrowly emarginate at middle. Mandible with external edge rounded, inner apex with 2 teeth. Mentum with apical half broadly triangular ( Fig. 19 ), notched at middle; palpomere 2 dorsoventrally flattened, about 3.0 times width of palpomere 1, setose; setae dense, moderately long, rufous, weakly thickened, curled at apex. Maxilla ( Fig. 29 ): mala with dense lamellate setal brush; stipes with setae dense, long, flattened at apex, curled at apex; palpomere 2 with internomedial bump and greatly enlarged. Antennal club subequal to segments 2–7. Pronotum: Bead lacking anterior to scutellum. Surface moderately densely punctate; punctures simple, unisetigerous laterally and apically; setae minute. Lateral margin lacking long setae. Elytral sutural length: About 4.2 times length of scutellum. Elytra: Surface with 7 poorly developed, punctate, longitudinal striae between suture and humerus; punctures ocellate, moderate in size, moderately dense, multisetigerous apically and laterally; setae minute (1–20+ per puncture) and short (0–1 per puncture). Intervals similarly sculptured. Propygidium: Surface shagreened and densely, confluently punctate; punctures simple, multisetigerous (laterally) and unisetigerous (near apex); setae minute (0–5+ per puncture) and short (0–1 per puncture), tawny. Pygidium: Surface densely punctate; punctures ocellate, multisetigerous; setae minute (7– 20+ per puncture) and long (0–1 per puncture). Venter: Prosternal keel elongate; apex projecting anteriorly at about 90° with respect to ventral plane, produced to about 1/2 of protrochanter, truncate. Mesometasternal apex invaginated, not produced. Legs: Foretibia of male tridentate (basal tooth very weakly developed); lateral margin with short, dense setae. Foretarsomere 5 subequal in length to tarsomeres 1–4, thickened; foretarsomeres 3–4 with apices weakly expanded, dorsal and ventral apices of tarsomeres 1–4 clothed with narrow patch of dense, short setae. Foreclaws of male with inner claw broadly curved ( Fig. 33 ), about 3 times thicker than outer claw; outer claw strongly arcuate, subequal in length to inner claw; empodium not bulbous at base. Meso­ and metatibial claws of male with 2 setae, claws weakly angled toward venter, about 1/2 length of metatarsomere 5. Metatibia of male with apical spurs nearly straight; ventral spur produced to middle of metatarsomere 1, dorsal spur produced to apex of metatarsomere 2. Parameres: Fig. 39a–c .

Diagnosis. This species is easily separated from other species of Peltonotus by the form of the mentum (broadly triangular; Fig. 19 ), the second maxillary palpomere that is greatly enlarged ( Fig. 29 ), the form of the smaller foreclaw of the male (strongly arcuate; Fig. 33 ), and form of the male genitalia ( Fig. 39 ). Other characters that are diagnostic are: mala with dense lamellate setal brush; foretibia of male tridentate (basal tooth very weakly developed) and lateral margin with short, dense setae.

Etymology. The specific epithet, “ deltamentum ”, refers to the form of the mentum that is triangular in the apical half (“ delta ” is Greek for “shaped like a triangle”).

Distribution (Fig. 67). West Kalimantan Province, Bornean Indonesia.

Locality record (1 specimen) from WADA .

BORNEAN INDONESIA. West Kalimantan Province (1): Balaikarangan.

Temporal Data. October (1).

Remarks. This species is known from a single male specimen.

Figures

FIGURES 19–28. Mentum, dorsal view of: 19) P. deltamentum, 20) P. gracilipodus, 21) P. kyojinus, 22) P. malayensis, 23) P. podocrassus, 24) P. nasutus, 25) P. nethis, 26) P. pruinosus, 27) P. similis, 28) P. sisyrus.

FIGURES 29–30. Maxilla (dorsal view) showing articulated maxillary tooth, mala with lamellate setal brush (black arrow), and form in: 29) P. deltamentum and 30) P. malayensis.

FIGURES 31–36. Detail of right forelegs of: 31) P. malayensis (showing bidentate foretibia, dorsal view), 32) P.rubripennis (showing tridentate foretibia with basal tooth very weakly developed, dorsal view), 33) P. deltamentum (showing strongly arcuate smaller claw, ventral view), 34) P. nasutus (showing form of foretarsomeres 1–5), 35) P.similis (showing form of foretarsomeres 1–5 and median protuberance of foretarsomere 5 [arrow]), 36) P. adelphosimilis (showing form of foretarsomeres 1–5 and apical protuberance of foretarsomere 5 [arrow]).

FIGURES 37–39. Male genitalia in dorsal (parameres only [a]) and lateral views (parameres and phallobase [b–c]) of: 37) P. adelphosimilis, 38) P. brunnipennis, 39) P. deltomentum.