Dilobitarsus lambirensis Arimoto & Kaliang & Mizuno & Meleng & Kishimoto-Yamada & Itioka 2025, sp. nov.

Dilobitarsus lambirensis Arimoto, sp. nov. (Figures 2–4) Type material (KIFDS). Malaysia, Sarawak, Miri, Lambir Hills National Park, by ultraviolet light traps. Holotype. Male, 17 m, 19–20 II 1996 [AA1214]. Paratypes (7 males). 1 male, 1 m, 6–7 X 1994 [AA1215]; 1 male, 17 m, 3–4 XI 1994 [AA1216]; 1 male, 35 m, 10–11 V 1994 [AA1217]; 1 male, 35 m, 11–12 VII 1994 [AA1218]; 1 male, 35 m, 21–22 XI 1998 [AA1219]; 1 male, 35 m, 21–22 XI 1998 [AA1220]; 1 male, 4 VII 2002 [AA1221]. Other material. 1 ex. (sex undetermined due to loss of abdomen), 35 m, 28–29 VI 1995 [AA1222; KIFDS]. Male. Diagnosis. Dilobitarsus lambirensis is distinguished from the congeners by the following combination of characters: pronotum with a black circular pattern formed by black scale-like setae on anterior part (Fig. 2A); elytra with V-shaped band formed by black scale-like setae (Fig. 2A); frontal carina wide U-shaped in ventral view (Fig. 3B, C); nasal plate moderately high laterally (Fig. 3C); antennae not reaching pronotal posterior lateral apices by antennomere XI (Fig. 2A); antennomere III 1.0–1.2 x longer than wide (Fig. 3E); antennomeres IV–V 0.9–1.1 x longer than wide (Fig. 3E); antennomere XI 1.95–2.1 x longer than wide (Fig. 3E); pronotum with four tubercles (Fig. 3G: arrows); prosternum without carina anterad of procoxal cavities (Fig. 3H); anterior edge of mesosternum with small median notch (Fig. 3K); elytron broadly convex (Fig. 4A); parameres with short lateral subapical barb (Fig. 4K, L); apex of parameres beyond lateral subapical barb 0.1 x total length of paramere (Fig. 4I, J), sub-trapezoidal and 1.0–1.15 x width at expansions in dorsal side (Fig. 4K); apical mesal edge of parameres emarginate between proximal and distal apices (Fig. 4K). Measurements (8 specimens; holotype in parentheses). BL: 11.7–15.3 (14.3), BW: 3.30–4.27 (4.09), MAE: 1.76–2.25 (2.09), MBE: 1.11–1.47 (1.39), OI: 151–160 (151), PL: 3.87–5.08 (4.84), PML: 3.36–4.36 (4.17), PW: 3.13–3.96 (3.77), PAW: 1.94–2.39 (2.29), PLI: 123–131 (128), PWI: 159–165 (165), EL: 7.50–9.61 (9.32), EW: 1.59–2.12 (2.06), EI: 453–479 (453), BI: 188–197 (192). Description. Body (Fig. 2A, B) elongate; surface generally smooth and shining, with wax-like coating on dorsal side (Fig. 2C), with large punctures; punctures on tubercles on pronotum smaller and denser; depression of hypomeron for reception of pro-femur and tibia without punctures; punctures at elytra smaller laterally and posterally; interspaces between punctures generally shorter than puncture diameter, but elytra interspaces vary from larger to smaller than puncture diameter. Color. Dorsal side black-brown but head, lateral margin of pronotum, and basal and apical parts of elytra red-brown; ventral side red-brown but prosternum and hypomera black-brown; mouthparts orange with labrum and mandibles black-brown, in some specimens maxillary palpi tinged with black; antennae and legs red-brown. Setae. Body covered with narrow scale-like setae (Fig. 2C); each outside of tarsal claws with thick seta at its base (Fig. 2D: arrow). Head with orange setae; pronotum with white to yellow-white setae posteriorly and laterally, with black setae forming a black circular pattern medioanteriorly, bordered with scattered orange setae; elytra with white to yellow-white setae, and a black V-shaped setal band around the middle, on and around the V-shaped band with scattered orange setae; setae on pronotal tubercles denser and erect; ventral surface with white to yellow-white setae. Head. Frontal region rectangular in dorsal view (Fig. 3A); frons depressed mesally (Fig. 3A, B); frontal carina complete and wide U-shaped (Fig. 3B, C); nasal plate moderately high laterally, strongly narrowed medially and divided by frontal carina (Fig. 3C), protruding beyond base of labrum (Fig. 3D). Eyes 0.25–0.3 x longer than interocular distance in dorsal view. Labrum semicircular. Antennae extended beyond half-length of pronotum and not reaching pronotal posterior lateral apices by antennomere XI (Fig. 2A); relative antennomere lengths: II<III– X<XI<I (Fig. 3E); antennomere I cylindrical; II globular, 0.8–1.0 x longer than wide; III trapezoidal, 1.0–1.2 x longer than wide, 1.5–1.7 x longer than II; IV–X serrated; IV 0.9–1.1 x longer than wide, 0.9–1.1 x longer than III, 0.55–0.65 x longer than II–III combined; V 0.95–1.0 x longer than wide, 0.9–1.05 x longer than IV; XI oblong ovate, 1.95–2.1 x longer than wide, 1.4–1.8 x longer than X. Mandibles bidentate (Fig. 3B). Apical maxillary palpomere securiform (Fig. 3F), 1.6–1.8 x longer than wide, shorter than eye maximum length; apical edge broadly rounded. Thorax. Pronotum sub-trapezoidal, 1.2–1.3 x longer than wide, widened posteriorly, broadly rounded laterally on posterior 2/3 and weakly constricted ahead of hind angles (Fig. 2A), widest across posterior lateral apices, roundly convex, tallest at posterior tubercles (Fig. 3D), with four tubercles, anterior two elevated slightly (Fig. 3D: white arrow, 3G: white arrows) and posterior two elevated strongly (Fig. 3D: black arrow, 3G: black arrows), without median longitudinal depression posteriorly; anterior angles strongly protruding beyond anterior edge (Fig. 2A), rounded apically; anterior edge slightly emarginate medially in dorsal view (Fig. 3A), weakly protruding medially in lateral view (Fig. 3D); lateral carinae complete; posterior angles short, acute, without carina; posterior edge without sublateral incision near each hind angle, elevated medially. Hypomeron depressed for reception of proleg, carinate behind depression for reception of pro-femur and tibia; anterior angle rounded apically; posterior edge with three notches mesally (Fig. 3H: arrows). Pronotosternal sutures (Fig. 2B) deeply grooved for reception of antennae, opened anteriorly; antennal groove extending to posterior angles of prosternum (Fig. 3H), becoming shallower posteriorly. Prosternum with carinate anterior edge (Fig. 2B); prosternal lobe weakly projecting, not reaching to the level of apices of anterior angles of prothorax (Fig. 3D), without carina anterad of procoxal cavities. Prosternal process 2.9–3.2 x longer than procoxal cavity length, weakly curved dorsally behind procoxae (Fig. 3D); dorsal lobe almost parallel-sided but gradually narrowed near apex in ventral view (Fig. 2B); ventral lobe abruptly narrowed posteriorly in ventral view and forming median carina on posterior 1/3, without subapical tooth (Fig. 3D); ventral margin broadly rounded in lateral view (Fig. 3D); ventral apex not reaching dorsal apex; dorsal and ventral apices rounded in ventral and lateral views (Figs 2B, 3D). Scutellar shield tongue-shaped, roundly expanded posteriorly (Fig. 3I), 1.2–1.3 x longer than wide, not visible in lateral view (Fig. 3D); anterior part inclined anterior-downwards and posterior part parallel to elytral surface (Fig. 3J); surface flat; anterior angles rounded; anterior edge weakly and roundly emarginated; apex broadly rounded. Mesosternum (Fig. 3K): anterior edge with small median notch, not lobate and sinuate on each side; mesosternal cavity floor with a median elongate band with fine setae; mesosternal cavity almost parallel-sided anteriorly in ventral view; borders of mesosternal cavity straight anteriorly and then curved ventrally obtusely in lateral view (Fig. 3D); mesosternal process between mesocoxae lower than mesocoxae, visible in lateral view (Fig. 3D); posterior edge 0.23–0.27 x wider than total width of mesosternum, straight (Fig. 3K); suture between mesosternum and metasternum present, but mesosternum and metasternum connate (Fig. 3K). Mesepisternum excavate anteriorly (Fig. 3K). Mesocoxal cavity closed to mesepisternum by mesosternum and mesepimeron (Fig. 3H, K). Metasternum depressed for reception of mid-tarsi, sulcate medially and ahead of metacoxal cavities (Fig. 2B). Metacoxal plate gradually narrowed toward outer side. Elytron broadly convex (Fig. 4A), with longitudinal carina at humerus (Fig. 3J: arrow), without striae, without any pattern on ventral side (Fig. 4B); apex rounded. Elytral apices not meeting at midline (Fig. 2A). Hind wings (Fig. 4C) fully developed, without veins CuA 1 and CuA 3+4; r4 translucent; mediomedial cross-vein between MP 1+2 and MP 3+4 present; mediocubital cross-vein between MP 3+4 and CuA 2 vestigial; radial cell more than 4 x wide. Tibiae without spurs (Fig. 4D); relative tarsomere lengths: IV<III<II<V<I (Fig. 4D); tarsomere IV with lobe ventrally (Fig. 4D: arrow); tarsal claws simple. Abdomen. Ventrite V curved triangular, rounded apically (Fig. 2B), 0.65–0.7 x longer than wide. Tergites and sternites VIII‒X yellow. Tergite VIII (Fig. 4E) curved triangular, longer than wide, narrowed posterad, rounded apically. Sternite VIII (Fig. 4F) hexagonal but with deep posterior median notch, shorter than wide, parallel-sided basally. Tergite IX (Fig. 4G) shorter than wide; anterior margin widely emarginate; posterior median notch deep, 0.2–0.3 x total length of tergite IX. Tergite X (Fig. 4G) semicircular, 1.0–1.1 x longer than wide, 0.6–0.7 x length of tergite IX. Sternite IX (Fig. 4H) elongate, widely constricted laterally but expanded at posterior 1/3, rounded apically. Aedeagus (Fig. 4I, J) yellow to brown, elongate. Phallobase 0.2–0.25 x total length of aedeagus, 0.7–0.8 x longer than wide. Median lobe gradually narrowed towards slender apex, not exceeding apices of parameres by its apex; basal struts 0.15–0.20 x total length of median lobe. Parameres separated ventrally, not constricted ahead of short lateral subapical barbs; apex beyond lateral subapical barb 0.1 x total length of paramere, sub-trapezoidal and 1.0–1.15 x width at expansions in dorsal side (Fig. 4K), with two to four long setae dorsally, one to two long setae laterally and one to two long setae ventrally; ventral side 1/3 x width of dorsal side around apex (Fig. 4L: arrow); proximal apex broadly rounded (Fig. 4K: white arrow); distal apex rounded (Fig. 4K: black ar