Biasticus taynguyenensis Ha, Truong & Ishikawa, 2022

Ha, Ngoc Linh, Truong, Xuan Lam, Ishikawa, Tadashi, Jaitrong, Weeyawat, Lee, Chi Feng, Chouangthavy, Bounsanong & Eguchi, Katsuyuki, 2022, Three new species of the genus Biasticus Stal, 1867 (Insecta, Heteroptera, Reduviidae, Harpactorinae) from Central Highlands, Vietnam, ZooKeys 1118, pp. 133-180 : 133

Biasticus taynguyenensis Ha, Truong & Ishikawa sp. nov.

Figs 5A , 6A-D , 13 , 14 , 15

Type material.

Holotype. ♀; HNL2018-073; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve; 08.v.2018; X. L. Truong leg.; NSMT. Paratypes. 1♀; HNL2018-036; Vietnam, Dak Lak Province, Chu Yang Sin National Park; 09.v.2018; X. L. Truong leg.; IEBR. 2♀; HNL2018-072; HNL2018-076; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve; 08.v.2018; X. L. Truong leg.; IEBR. 1♀; HNL2018-074; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve; 08.v.2018; X. L. Truong leg.; NSMT. 1♀; HNL2018-075; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve; 08.v.2018; X. L. Truong leg.; VNMN. 1♂; TXL2016-545; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve; 28.iv.2016; X. L. Truong leg.; NSMT.

Diagnosis.

Body shiny blackish brown; anterior pronotal lobe blackish brown or black with some rows of short bent cream-yellow setae; posterior pronotal lobe blackish brown or dark brown, densely covered with short bent cream-yellow setae, interspersed with long erect setae; scutellum black or blackish brown; abdominal sternites sanguineous; laterotergites II-IV luteous; anterior half of laterotergite V suffused with brown; posterior half of laterotergite V to apex of abdomen sanguineous.

This species is similar to B. confusus Hsiao et al., 1979 in general appearance, especially in body color, pronotum, and thoracic sterna. But the new species can be distinguished from B. confusus by a combination of the following characters: antennal pedicel longer than first flagellomere (in B. confusus pedicel as long as first flagellomere), second flagellomere as long as pedicel (in B. confusus second flagellomere longer than pedicel), proportional average length of first to third labial segments 1.1:1.4:0.3 (in B. confusus 0.9:1.2:0.3), anterior pronotal lobe with some rows of bent setae (in B. confusus without row of bent setae), posterior pronotal lobe ~ 2.3 × as long as anterior pronotal lobe (in B. confusus 2.0 ×), and apical margin of median process of pygophore weakly and continuously concave (in B. confusus weakly and continuously convex).

Furthermore, this species is somewhat similar to B. ventralis Hsiao et al., 1979 in general colors of body, pronotum, and sterna but the new species can be distinguished from B. ventralis by a combination of the following characters: antennal pedicel longer than first flagellomere (in B. ventralis pedicel ~ 1/2 as long as first flagellomere), second flagellomere as long as pedicel (in B. ventralis second flagellomere 2.5 × as long as pedicel), proportional average length of antennal scape, pedicel, first and second flagellomeres 3.1:1.6:1.4:1.6 (in B. ventralis 3.3:1.1:2.0:2.8), and proportional average length of first to third labial segments 1.1:1.4:0.3 (in B. ventralis 1.0:1.3:0.3).

Description.

Female description. Coloration. Body shiny blackish brown. Head dorsum shiny black or blackish brown; clypeus blackish brown; antenniferous tubercle, base of neck, maxillary plate, and base of first visible labial segment yellowish brown; central fascia to head venter, gena, tips of first and second visible labial segments pale luteous; labium, except base of first visible labial segment, black; a brown stripe present after postero-upper corner of compound eye; area around lateral ocellus with reddish brown suffusion; a longitudinally elongated yellowish brown spot present between lateral ocelli. Base of scape dark brown; remaining of scape brown; pedicel, first and second flagellomeres brown, darker toward tip. Collar, anterior pronotal lobe, thoracic sterna, and pleura blackish brown or black; posterior pronotal lobe blackish brown; scutellum black or blackish brown; stridulatory sulcus, intersecting area of coxa and trochanter yellowish brown; coxae, trochanters, femora, and tibiae blackish brown. Corium and clavus blackish brown, apically brownish yellow; membrane bronzy brown, semi-hyaline. Hind wings faintly semi-hyaline. Abdominal mediotergites I+II to IV and middle of mediotergite V blackish brown; posterior half of mediotergite V to apex of abdomen and abdominal sternites sanguineous; laterotergites II-IV luteous; anterior half of laterotergite V suffused with brown; posterior half of laterotergite V to apex of abdomen sanguineous. Female external genitalia sanguineous.

Structure. Body medium-sized (BL = 10.38-11.35 mm), elongate, and somewhat robust. Head subelongate and robust (HL/PoW = 2.40-2.59), shorter than pronotum (HL/PnL = 0.80-0.86); postocular area of head sub-globose (PoL/PoW = 0.84-0.96), distinctly wider than anteocular area (PoW/AoW = 1.38-1.43), approximately as long as anteocular area (PoL/AoL = 0.95-1.08), constricted behind compound eyes, with a wide and deep interocular sulcus; neck short. Compound eyes protruding laterally, nearly globose, with posterior margin sub-straight; lateral ocelli produced, elevated behind interocular sulcus, widely separated from each other (OCD/PoW = 0.44-0.49); interspace between lateral ocelli wider than distance between compound eye and lateral ocellus (OCD/COD = 2.03-2.06). First visible labial segment shorter than second segment (R1L/R2L = 0.76-0.84), longer than anteocular area of head (R1L/AoL = 1.42-1.60), extending beyond level of middle of compound eye when labium laid backward; proportional average length of first to third visible labial segments 1.1:1.4:0.3. Scape ~ 1.5 × as long as head; pedicel slightly longer than first flagellomere and nearly equal in length to second flagellomere; proportional average length of scape, pedicel, first and second flagellomeres 3.1:1.6:1.4:1.6. Collar very short in dorsal view, with anterolateral angle weakly and roundly produced; anterior pronotal lobe round and bulged, slightly rough, with middle longitudinal sulcus deep and narrow posteriorly; posterior pronotal lobe with slightly swollen anteromedial elevation; humerus roughly triangular, with round apex; posterior margin of pronotum straight; posterior angles round, not exceeded to posterior margin of pronotum. Scutellum triangular, somewhat triangularly depressed basally, apically produced, and sloping downward; posterior apex round; anterior margin slightly convex. Femora thick, apically moderately nodulose; fore femora very slightly incrassated, thicker than mid and hind femora. Hemelytra surpassing apex of abdomen when fully closed, 0.8 × as long as body length; discal cell nearly parallelogram-shaped, twice as long as width; Sc 0.8 × as long as hemelytron length, 1.5 × as long as R + M. Hind wing ~ 3.4 × as long as maximum width. Connexivum slightly dilated and ascending with segmental incisures; abdominal laterotergite VIII (AL8) with thin posterior margin (0.03 mm); abdominal sternite VII (AS7) forming a semi-circular or wide sub-pentagonal median concavity, with posteromedian margin gently U-shaped, with inner posterolateral margin almost straight; gonocoxa VIII (Gc8) ~ 1.3 × wider than length, gently slanting anteromesad along posterior margin, weakly produced mesad and forming an acute apex at apical inner corner, and with inner margin weakly incurved in posterior 2/3; gonapophysis (Gp8) small and subtriangular, 3.2 × longer than width; gonoplac (Gpl) V-shaped, thin, with maximum thick ~ 0.025 mm.

Vestiture. Body clothed with cream-yellow setation. Head, except interocular sulcus and area along anterior margin of compound eye, covered with short bent cream-yellow pubescence, and sparsely with long erect setae; labium with a few bent setae; scape without setae and pubescence; pedicel, first and second flagellomeres with short vertical setae; neck glabrous. Collar, anterior margin, lateral area of anterior pronotal lobe, posterior pronotal lobe, scutellum, pleura, thoracic sterna, and coxae densely covered with short bent cream-yellow pubescence; posterior pronotal lobe, pleura, thoracic sterna, and coxae interspersed with long erect setae; scutellum with long bent slender setae, especially in lateral slopes and in posterior apex; trochanters, femora, and tibiae with short erect setae; corium with short bent setae. Abdomen (including connexivum), except segment VII, with short slender vertical setae; gonocoxa VIII (Gc8) with long slender bent setae.

Male description. General external morphology similar to that of the female.

Coloration. Almost similar to female but slightly brighter than female. Clypeus dark brown; anteclypeus, base of first visible labial segment pale yellowish brown; first and third visible labial segments brown; second visible labial segment dark brown; area around ocellus with pale brown suffusion. Prosternum and propleuron blackish brown; posterior pronotal lobe dark brown; scutellum blackish brown; meso- and metapleura brown or yellowish brown; meso- and metasterna yellowish brown; fore coxa pale yellowish brown; coxae and trochanters of mid and hind legs yellowish brown; femora and tibiae dark brown or blackish brown. Pygophore ventrally orangish sanguineous; paramere semi-hyaline, pale orange.

Structure. Almost same as female except for the following characters. Scape 1.7 × as long as head; pedicel, first and second flagellomeres missing. Hemelytra surpassing apex of abdomen when fully closed, nearly 0.9 × as long as body length. Pygophore elliptic; median process of pygophore (mpp) broad and low, 0.3 × as long as wide, with apical margin weakly and continuously concave, with apicolateral corner distinctly produced posterolaterad and pointed; paramere long, slender, clavate, somewhat incurved in apical part, with round apex (Figs 6A , 15B-E ). Aedeagus in dorsal view ovoid, dorsally sclerotized (Figs 6B , 15F, I ) and in lateral view long and narrow (Figs 6C , 15G, K ); articulatory apparatus (aa) in ventral view with basal plate arms relatively slender and jointly forming a U-shape, and in lateral view arched very strongly (Figs 6C, D , 15G, H ); dorsal phallothecal sclerite (dps) in lateral view with posteromedian part weakly produced posterodorsad (Figs 6C , 15G, K ); spoon-like sclerites (sps) hyaline and glabrous; both membranous sac-like lobes posterolaterally produced; distal dorsal lobe of endosoma (ddl) round, with membranous surface roughly lumpy (Fig. 15L ).

Vestiture. Almost same as female except for the following characters. Head covered with short bent cream-yellow pubescence, and sparsely with long bent setae; pedicel with short vertical setae; first and second flagellomeres missing; neck without setae. Scutellum densely covered with short bent cream-yellow pubescence interspersed with long erect setae; trochanters, femora, and tibiae with long erect setae; connexivum with long vertical thick setae; abdominal venter with vertical setae; pygophore with oblique setae; paramere with long erect setae.

Measurements.

All dimensions are given in mm. Holotype (♀): BL 11.35; HL 2.12; AoL 0.76; AoW 0.58; PoL 0.76; PoW 0.82; OE 1.11; IE 0.57; ED 0.65; OD 0.17; OCD 0.41; COD 0.19; R1L 1.22; R2L 1.45; R3L 0.33; A1L 3.13; A2L 1.67; A3L 1.55; A4L n/a; PnL 2.52; PnW 3.01; APL 0.72; PPL 1.80; HeL 8.61; HeW 2.97; Sc 6.59; R+M 4.43; HWL 6.06; HWW 1.84; AFL 3.32; ATL 4.02; MFL 2.76; MTL 3.41; PFL 4.02; PTL 5.53. Paratype (♂): BL 9.86; HL 1.98; AoL 0.68; AoW 0.56; PoL 0.78; PoW 0.79; OE 1.03; IE 0.54; ED 0.61; OD 0.14; OCD 0.38; COD 0.21; R1L 1.11; R2L 1.39; R3L 0.31; A1L 3.28; A2L n/a; A3L n/a; A4L n/a; PnL 2.31; PnW 2.60; APL 0.70; PPL 1.60; HeL 8.48; HeW 2.72; Sc 6.56; R+M 4.34; HWL 5.60; HWW 1.70; AFL 3.30; ATL 3.91; MFL 2.73; MTL 3.29; PFL 4.00; PTL 5.45. Paratypes (♀). BL 10.38-10.81; HL 2.00-2.06; AoL 0.72-0.75; AoW 0.58-0.60; PoL 0.70-0.78; PoW 0.82-0.86; OE 1.06-1.09; IE 0.54-0.58; ED 0.62-0.63; OD 0.15-0.17; OCD 0.37-0.41; COD 0.17-0.19; R1L 1.07-1.13; R2L 1.37-1.42; R3L 0.31-0.32; A1L 2.99-3.13; A2L 1.52-1.60; A3L 1.25-1.52; A4L 1.44-1.74; PnL 2.36-2.51; PnW 2.73-2.87; APL 0.66-0.81; PPL 1.64-1.82; HeL 8.63-8.98; HeW 2.78-3.04; Sc 6.59-6.71; R+M 4.51-4.62; HWL 6.03-6.18; HWW 1.77-1.87; AFL 3.11-3.41; ATL 3.79-3.93; MFL 2.64-2.77; MTL 3.30-3.42; PFL 3.73-4.00; PTL 5.35-5.50.

Distribution.

Vietnam, Central Highlands (Gia Lai, Dak Lak).

Type locality.

Vietnam, Central Highlands, Gia Lai Province, Kon Chu Rang Nature Reserve.

Etymology.

This new species is named after the Tay Nguyen region, the local name of Central Highlands.

Figures

Figure 5. Female external genitalia of six morphospecies in ventral view A type fA, Biasticus taynguyenensis Ha, Truong & Ishikawa, sp. nov., holotype, ♀, HNL 2018 - 073 B type fB, B. griseocapillus Ha, Truong & Ishikawa, sp. nov., holotype, ♀, HNL 2018 - 038 C type fC, B. luteicollis Ha, Truong & Ishikawa, sp. nov., paratype, ♀, HNL 2018 - 024 D type fD, B. flavinotus (Matsumura, 1913), ♀, HNL 2018 - 117 E type fE, B. confusus Hsiao et al., 1979, ♀, VN-Hem- 1998 - 012 F type fF, B. flavus (Distant, 1903), ♀, LA-Redu- 2004 - 006.

Figure 6. Male genitalia of four morphospecies A-D type mA, Biasticus taynguyenensis Ha, Truong & Ishikawa, sp. nov., paratype, ♂, TXL 2016 - 545 E-I type mB, B. griseocapillus Ha, Truong & Ishikawa, sp. nov., paratype, ♂, TXL 2016 - 546 J-N type mC, B. luteicollis Ha, Truong & Ishikawa, sp. nov., holotype, ♂, HNL 2018 - 025 O-R mF, B. flavus (Distant, 1903), ♂, HEM-TH 2004 - 018. A, E, J, O pygophore with paramere (s) in dorsal view B, F, K, P phallus in dorsal view C, G, L, Q phallus in lateral view D, I, N, R articulatory apparatus H, M distal dorsal lobe of endosoma.

Figure 13. Biasticus taynguyenensis Ha, Truong & Ishikawa, sp. nov., holotype, ♀, HNL 2018 - 073 A body in dorsal view B body in lateral view C head in dorsal view D head in lateral view.

Figure 14. Biasticus taynguyenensis Ha, Truong & Ishikawa, sp. nov., holotype, ♀, HNL 2018 - 073 A pronotum in dorsal view B anterior pronotal lobe in dorsal view C, D setae on posterior pronotum E right hemelytron F right hind wing.

Figure 15. Biasticus taynguyenensis Ha, Truong & Ishikawa, sp. nov. A female genitalia in ventral view, holotype, ♀, HNL 2018 - 073 B-L male genitalia, paratype, ♂, TXL 2016 - 545 B-E pygophore with parameres B dorsal view C lateral view D ventral view E apical portion of pygophore, showing median process (mpp) and parameres F-L phallus F dorsal view G lateral view H articulatory apparatus (aa) I aedeagus with endosoma semi-everted dorsal view J aedeagus with endosoma semi-everted, ventral view K aedeagus with endosoma semi-everted, lateral view L distal dorsal lobe of endosoma (ddl).