Biasticus griseocapillus 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 griseocapillus Ha, Truong & Ishikawa sp. nov.

Figs 5B , 6E-I , 16 , 17 , 18

Type material.

Holotype. 1♀; HNL2018-038; Vietnam, Dak Lak Province, Chu Yang Sin National Park; 09.v.2018; X. L. Truong leg.; NSMT. Paratypes. 1♀; HNL2018-007; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve; 05.v.2018; X. L. Truong leg.; IEBR. 1♀; HNL2018-037; Vietnam, Dak Lak Province, Chu Yang Sin National Park; 09.v.2018; X. L. Truong leg.; VNMN. 1♂; TXL2016-546; 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 black or blackish brown with some rows of long bent griseous setae; posterior pronotal lobe blackish brown or brown and densely covered with short bent griseous setae somewhat interspersed with long griseous setae; scutellum black in basal half and dark brown or brown in lateral margin and apical half; abdominal sternites shiny sanguineous; laterotergites II-VI luteous, segmentally suffused with dark brown spots or blackish brown spots; laterotergite VII sanguineous.

In general appearance, Biasticus griseocapillus sp. nov. resembles B. confusus Hsiao et al., 1979, especially in general colors of body, pronotum, and 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 of antenna as long as pedicel (in B. confusus second flagellomere longer than pedicel), proportional average length of first to third visible 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 2.6 × as long as anterior pronotal lobe (in B. confusus 2.0 ×), and apical margin of median process of pygophore weakly convex and emarginate at middle (in B. confusus weakly convex without such emargination).

Furthermore, this species is 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 3.0:1.6:1.4:1.6 (in B. ventralis 3.3:1.1:2.0:2.8), and proportional average length of first to third visible labial segments 1.1:1.4:0.3 (in B. ventralis 1.0:1.3:0.3).

Also, Biasticus griseocapillus sp. nov. is similar to B. taynguyenensis sp. nov. in the body color pattern, the proportion average length of the antenna segments, and the proportion average length of the visible labial segments. However, B. griseocapillus can be distinguished from the latter by a combination of the following characters: collar, anterior pronotal lobe, and posterior pronotal lobe covered with long bent griseous setae (in B. taynguyenensis short bent cream-yellow setae), and median process of pygophore (mpp) 0.2 × as long as wide, with apical margin weakly convex and emarginate medially, and with apicolateral corner slightly produced laterad and pointed (in B. taynguyenensis , 0.3 × as long as wide, with apical margin weakly and continuously concave, and with apicolateral corner distinctly produced posterolaterad and pointed).

Description.

Female description. Coloration. Body shiny blackish brown. Head dorsum (except anteclypeus, maxillary plate, and gena) black; anteclypeus, labrum, maxillary plate, and anterior region of gena brown; central fascia to head venter, and posterior region of gena pale luteous; first visible labial segment brown; second and third visible labial segments blackish brown; tips of first and second visible labial segments yellowish brown; area around lateral ocellus with reddish brown suffusion; a longitudinally elongated yellowish brown spot present between lateral ocelli. Base of scape brownish black; remaining of scape and pedicel, first and second flagellomeres blackish brown. Collar, anterolateral angles, anterior pronotal lobe, and anterior acetabulum black; posterior pronotal lobe, pleura, and thoracic sterna blackish brown; scutellum black in basal half and dark brown in lateral margin and apical half; stridulatory sulcus luteous; coxae and trochanters yellowish brown; intersecting area of fore coxae and fore trochanters luteous; femora, tibiae, and tarsi blackish brown. Corium and clavus darkish brown, apically brownish yellow; membrane bronzy brown, semi-hyaline. Hind wings faintly semi-hyaline. Abdominal mediotergites I+II to V reddish brown or sanguineous, somewhat suffused with blackish brown; mediotergite VI suffused with reddish brown and irregularly suffused with sanguineous; mediotergite VII and laterotergite VII to apex of abdomen sanguineous; abdominal sternite shiny sanguineous; laterotergites II-VI luteous, segmentally suffused with dark brown spots; laterotergite VII sanguineous. External genitalia sanguineous.

Structure. Body medium-sized (BL = 10.61-10.84 mm), elongate, and somewhat robust. Head subelongate and robust (HL/PoW = 2.37-2.45), shorter than pronotum (HL/PnL = 0.81-0.82); postocular area of head sub-globose (PoL/PoW = 0.85-1.03), distinctly wider than anteocular area (PoW/AoW = 1.44-1.47), slightly longer than anteocular area (PoL/AoL = 1.05-1.27), 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 = 0.43-0.46); interspace between lateral ocelli wider than distance between compound eye and lateral ocellus (OCD/COD = 1.93-2.17). First visible labial segment shorter than second segment (R1L/R2L = 0.80-0.84), longer than anteocular area of head (R1L/AoL = 1.58-1.63), extending beyond level of middle of compound eye when labium laid backward; proportional average length of first to third visible labial segments 1.1:1.3:0.3. 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 3.0:1.6:1.4:1.6. 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 0.7 × as long as hemelytron length, 1.4 × as long as R + M. Hind wing ~ 3.2 × as long as maximum width. Connexivum slightly dilated and ascending with segmental incisures; abdominal laterotergite VIII (AL8) with thin posterior margin (0.01 mm); abdominal sternite VII (AS7) forming a wide subpentagonal posteromedian concavity, with inner posterolateral margin almost straight; gonocoxa VIII (Gc8) broad, ~ 1.4 × wider than length, slightly opened inward for gonapophyses VIII (Gp8), with posterior margin gently slanting anteromesad, and with apical inner corner not produced; Gp8 small and subtriangular, 3.9 × longer than width; gonoplac (Gpl) V-shaped, thin, with maximum thick ~ 0.025 mm.

Vestiture. Body clothed with griseous setation. Head, except interocular sulcus and posterior margin of clypeus, covered with long erect setae; posterior margin of clypeus, head venter, anterolateral area of neck with short bent setae and sparsely with long erect setae; anteclypeus, labium, scape with a few short setae; pedicel, first and second flagellomeres covered with short erect to recumbent setae; dorsum of neck without setae. Collar, anterior margin of anterior pronotal lobe with dense bent pubescence; anterior pronotal lobe with some rows of long bent griseous setae; lateral area of anterior pronotal lobe with long erect setae; posterior pronotal lobe densely covered with short bent griseous setae somewhat interspersed with long griseous setae; lateral slope area and posterior apex of scutellum with dense short to long setae; posterior area of posterior pronotal lobe with long erect setae; pleura, thoracic sterna, and coxae with short bent setae; trochanters, femora, and tibiae with long erect setae; corium with bent griseous pubescence. Anterior margin of abdominal mediotergite I+II with some long slender erect yellowish brown setae; mediotergites and dorsal laterotergites sparsely covered with a few short vertical setae; abdominal sternites interspersed with long vertical setae; posterior margin of abdominal laterotergite VIII (AL8) with long erect slender setae; gonocoxa VIII (Gc8) with long slender bent setae; apex of external genitalia with long thick erect setae.

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

Coloration. Almost similar to female but brighter than female. Gena brown in anterior half and luteous in posterior half; labium blackish brown; tips of first and second visible labial segments luteous. Collar, anterolateral angles, anterior pronotal lobe, and anterior acetabulum blackish brown; posterior pronotal lobe, pleura, and thoracic sterna brown; scutellum black in basal half and brown in lateral margin and apical half; stridulatory sulcus pale gray. Laterotergites II-VI pale luteous, segmentally suffused with blackish brown spots; laterotergite VII sanguineous. Pygophore ventrally orpiment-orange; paramere semi-hyaline, pale orange.

Structure. Almost similar to female except for the following characters. Scape 1.8 × as long as head and more than twice as long as pedicel; pedicel slightly longer than first flagellomere; second flagellomere missing; proportional length of scape, pedicel, and first flagellomere 3.5:1.6:1.4. Hemelytra surpassing apex of abdomen when fully closed, 0.9 × as long as body; Sc 0.8 × as long as hemelytron, and 1.5 × as long as R + M. Pygophore ovoid; median process of pygophore (mpp) broad and low, 0.2 × as long as wide, with apical margin weakly convex and emarginate medially, with apicolateral corner slightly produced laterad and pointed; paramere long, slender, clavate, somewhat curved medially, and apically subnodulose and round (Figs 6E , 18B-F ). Aedeagus in dorsal view ovoid, dorsally sclerotized (Figs 6F , 18G, J ) and in lateral view long and narrow (Figs 6G , 18H, L ); articulatory apparatus (aa) in ventral view with basal plate arms relatively slender and jointly forming a U-shape, and in lateral view arched strongly (Figs 6G, I , 18H, I ); dorsal phallothecal sclerite (dps) in lateral view with posteromedian part weakly produced posterodorsad (Figs 6G , 18L ); spoon-like sclerites (sps) hyaline and glabrous; both membranous sac-like lobes posterolaterally produced; distal dorsal lobe of endosoma (ddl) round, with membranous surface covered with large hyaline prickles (Figs 6H , 18M ).

Vestiture. Almost similar to female except for the following characters. Posterior margin of clypeus with short bent pubescence; anteclypeus and scape without setae. Collar and anterior margin of anterior pronotal lobe with short bent setae and some long bent setae; anterior pronotal lobe with some rows of long bent griseous setae; posterior pronotal lobe with bent griseous setae; scutellum with long slender erect setae abundantly, especially in lateral slopes; posterior apex of scutellum with a pinch of long slender erect and bent setae; pleura, thoracic sterna, and coxae with short bent setae, with a few long slender setae; trochanters sparsely with short bent pubescence and a few long setae; corium with bent pubescence. Pygophore ventrally covered with a few bent pubescence, more abundant laterally; paramere with a few long erect thick setae.

Measurements.

All dimensions are given in mm. Holotype (♀): BL 10.84; HL 1.99; AoL 0.67; AoW 0.56; PoL 0.85; PoW 0.82; OE 1.05; IE 0.56; ED 0.60; OD 0.17; OCD 0.36; COD 0.18; R1L 1.09; R2L 1.31; R3L 0.32; A1L 3.01; A2L 1.59; A3L 1.52; A4L 1.56; PnL 2.45; PnW 2.74; APL 0.79; PPL 1.67; HeL 8.56; HeW 2.67; Sc 6.69; R+M 4.67; HWL 5.68; HWW 1.68; AFL 3.37; ATL 4.00; MFL 2.77; MTL 3.47; PFL 3.94; PTL 5.44. Paratype (♂): BL 9.77; HL 1.91; AoL 0.64; AoW 0.54; PoL 0.78; PoW 0.79; OE 1.05; IE 0.53; ED 0.63; OD 0.14; OCD 0.38; COD 0.19; R1L 1.05; R2L 1.31; R3L 0.29; A1L 3.48; A2L 1.62; A3L 1.49; A4L n/a; PnL 2.12; PnW 2.57; APL 0.59; PPL 1.52; HeL 8.45; HeW 2.79; Sc 6.78; R+M 4.52; AFL 3.44; ATL 4.06; MFL 2.90; MTL 3.52; PFL 3.99; PTL 5.36. Paratypes (♀). BL 10.61-10.75; HL 1.94-1.95; AoL 0.67; AoW 0.54-0.57; PoL 0.70-0.76; PoW 0.79-0.82; OE 1.05; IE 0.54-0.55; ED 0.58-0.62; OD 0.16; OCD 0.36-0.38; R1L 1.05-1.06; R2L 1.27-1.31; R3L 0.31-0.34; A1L 2.92-2.97; A2L 1.57-1.61; A3L 1.36-1.43; A4L 1.60-1.64; PnL 2.36-2.38; PnW 2.58-2.74; APL 0.72-0.84; PPL 1.52-1.66; HeL 8.65-8.88; HeW 2.75-2.98; Sc 6.30-6.49; R+M 4.40-4.48; HWL 5.78-5.89; HWW 1.79-1.91; AFL 3.31-3.33; ATL 3.78-3.93; MFL 2.70-2.78; MTL 3.42-3.51; PFL 3.69-3.87; PTL 4.91-5.35.

Distribution.

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

Type locality.

Vietnam, Central Highlands, Dak Lak Province, Chu Yang Sin National Park.

Etymology.

This new species is named after griseous pubescence on the pronotum.

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 16. Biasticus griseocapillus Ha, Truong & Ishikawa, sp. nov., holotype, ♀, HNL 2018 - 038 A body in dorsal view B body in lateral view C head in dorsal view D head in lateral view.

Figure 17. Biasticus griseocapillus Ha, Truong & Ishikawa, sp. nov., holotype, ♀, HNL 2018 - 038 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 18. Biasticus griseocapillus Ha, Truong & Ishikawa, sp. nov. A female genitalia in ventral view, holotype, ♀, HNL 2018 - 038 B-M male genitalia, paratype, ♂, TXL 2016 - 546 B-F pygophore with paramere B dorsal view C lateral view D ventral view E apical portion of pygophore, showing median process (mpp) and paramere F left paramere G-M phallus G dorsal view H lateral view I articulatory apparatus (aa) J aedeagus with endosoma semi-everted, dorsal view K aedeagus with endosoma semi-everted, ventral view L aedeagus with endosoma semi-everted, lateral view M distal dorsal lobe of endosoma (ddl).