Sycanus thuathienhuensis Truong & Ha, sp. nov., 2024

Truong, Xuan Lam, Giang, Phan Thi, Nguyen, Dai Dac, Chau, Tran Pham Minh & Ha, Ngoc Linh, 2024, Two new species of the genus Sycanus Amyot & Serville (Insecta: Hemiptera: Reduviidae: Harpactorinae) from Vietnam, Zootaxa 5481 (3), pp. 301-325 : 313-318

Sycanus thuathienhuensis Truong & Ha, sp. nov.

( Figs. 4A , 6 , 7 )

Type material. Holotype. ♂; TXL2024-012; Vietnam, Thua Thien Hue Province, Bach Ma National Park ; 02.ii.2024; XL Truong leg.; IEBR . Paratypes. 1♂; TXL2018-004; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve ; 05.v.2018; XL Truong leg.; IEBR . 1♂; NDD2022-009; Vietnam, Quang Nam Province, Tay Giang Forest ; 01.v.2022; DD Nguyen leg.; IEBR . 1♀; NDD2022-063; Vietnam, Quang Nam Province, Tay Giang Forest ; 1.v.2022; DD Nguyen leg.; IEBR . 1♀; TXL2024-059; Vietnam, Thua Thien Hue Province, Bach Ma National Park ; 02.ii.2024; XL Truong leg.; IEBR . 2♀; PTG2024-060; PTG2024-061; Vietnam, Thua Thien Hue Province, Bach Ma National Park ; 04.ii.2024; PT Giang leg.; IEBR . 1♀; PTG2024-062; Vietnam, Thua Thien Hue Province, Bach Ma National Park ; 05.ii.2024; PT Giang leg.; IEBR .

Non-type material. 1♂; TXL2016-514; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve ; 26.iv.2016; XL Truong leg.; IEBR . 1♀; TXL2016-521; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve ; 27.iv.2016; XL Truong leg.; IEBR . 1♀; TXL2016-604; Vietnam, Dak Lak Province, Chu Yang Sin National Park ; 4.v.2016; XL Truong leg.; IEBR . 4♀; TXL2018-001; TXL2018-002; TXL2018-003; TXL2018-005; Vietnam, Gia Lai Province, Kon Chu Rang Nature Reserve ; 05.v.2018; XL Truong leg.; IEBR . 2♀; TXL2018-043; TXL2018-044; Vietnam, Dak Lak Province, Chu Yang Sin National Park ; 08.v.2018; XL Truong leg.; IEBR . 1♀; NDD2022-024; Vietnam, Quang Nam Province, Tay Giang Forest ; 02.v.2022; DD Nguyen leg.; IEBR .

Diagnosis. Body ochreous; anterior pronotal lobe black with some rows of short bent cream-yellow short and slender setae ( Fig. 6F ); posterior pronotal lobe ochreous, rugulose, punctured, covered with short erect slender setae ( Fig. 6F ); scutellum black with yellow latero-posterior margin ( Fig. 6F ); scutellar spine sub-vertical, short or almost tubercle-liked (0.44–1.53 mm), not bifid at apex, yellow or brownish-yellow with black base ( Fig. 6B, F ); coria yellow or ochreous with transection with clavus dark brown, clavus dark brown ( Fig. 6G ); male pygophore brownish yellow with ventrally centrally largely suffused with dark brown or blackish brown ( Fig. 6C ).

This species is very similar to Sycanus croceus in general appearance, especially in body colour, pronotum, and thoracic sterna. But the new species can be distinguished from S. croceus by a combination of the following characteristics: a brownish yellow stripe running between postero-upper corner of compound eye and ocellus of same side ( Fig. 6E ) (in S. croceus without any yellow stripe), abdominal sternites with small longitudinal black markings segmentally laterally ( Fig. 6C ) (in S. croceus with small round spots segmentally laterally), large marking of laterotergite V reach antero-lateral margin of laterotergite V (in S. croceus not extend to the antero-lateral margin), scutellar spine short or almost tubercle-liked, not bifid at apex, yellow or brownish-yellow with black base ( Figs. 6B, F ) (in S. croceus long, apex bi-forked, wholly yellow or orange), distal dorsal lobe of endosoma (ddl) with two very large and long horn-shaped prickles centrally, surrounded by large prickles ( Fig. 7I–K ) (in S. croceus ddl with two large horned processes, apical part laterally with three pairs of larger spines and eight pairs of smaller spines).

Moreover, the new species is also similar to Sycanus insularis in general morphology. But the former can be distinguished from the latter by the following features: abdominal sternites with small longitudinal black markings segmentally laterally ( Fig. 6C ) (in S. insularis with small round spots segmentally laterally), scutellar spine short or almost tubercle-liked, not bifid at apex, yellow or brownish-yellow with black base ( Fig. 6B, F ) (in S. insularis long, apex bifid, black or yellow), coria yellow or ochreous with transection with clavus dark brown, clavus dark brown brown ( Fig. 6G ) (in S. insularis anterior half black or dark brown, remaining pale yellow or luteous).

Furthermore, the new species has a very close relationship to Sycanus rufus in molecular phylogenetic analyses with a minimum interspecific divergence of 2.0% in p-distance and 0.02 in K 2P. However, the two species can be delimited by the external morphology, i.e., body ochreous (in S. rufus body red), posterior pronotal lobe ochreous, rugulose, punctured, covered with short erect slender setae ( Fig. 6F ) (in S. rufus red, rugulose, not punctured, clothes with procumbent short yellow setae), distal dorsal lobe of endosoma (ddl) with two very large and long horn-shaped prickles centrally, surrounded by large prickles ( Figs. 7I–K ) (in S. rufus ddl with two long and slender prickles, and laterally with two pairs of larger spines and about 10 pairs of smaller spines).

Male description.

Coloration. Body ochreous. Head dorsum, neck, clypeus, maxillary plate, antenniferous tubercles, and posterior half of head venter black; labrum and anterior margin of gena dark brown; gena and anterior half of head venter luteous or yellow; a brownish yellow stripe running between postero-upper corner of compound eye and ocellus of same side; first visible labial segment blackish brown at basal half, paler as dark brown toward tip; base of second visible labial segment dark brown; remaining of labium brown, paler toward tip ( Fig. 6D, E ). Scape, pedicel, and first flagellomere blackish brown; second flagellomere dark brown, paler toward tip. Collar, anterolateral angle, anterior margin of anterior pronotal lobe, acetabulum, prosternum, and stridulatory sulcus yellow ( Fig. 6F ); posterior pronotal lobe yellow or ochreous ( Fig. 6F ); scutellum black with yellow latero-posterior margin ( Fig. 6F ); scutellar spine yellow or brownish-yellow with black base or wholly black ( Fig. 6F ); meso- and metapleura, meso- and metasterna, black or blackish brown; coxae yellow; trochanters blackish brown; femora, tibiae, and tarsi black or blackish brown. Coria yellow or ochreous with transection with clavus dark brown; clavus dark brown; membrane pale bronzy brown, semi-hyaline ( Fig. 6G ). Hind wings faintly semi-hyaline ( Fig. 6H ). Abdominal mediotergites blackish brown or black with irregular brown or yellow suffusions; laterotergites yellow or orangish yellow with lateral half of red, reddish yellow, or orange ( Fig. 6B ); laterotegites III–VII segmentally large black marking; large marking of laterotergites VI and V reach antero-lateral margin of latetotergites; large marking of laterotergites III, VI, and VII far from reaching the lateral margin of laterotergites; abdominal sternites yellow or luteous with broad transversal black strip in anterior margin of each segment and discontinuous medial longitudinal black strip and small longitudinal black markings segmentally laterally ( Fig. 6C ). Pygophore brownish yellow with ventrally centrally largely suffused with dark brown or blackish brown ( Fig. 6C ).

Structure. Body large-sized (17.40–19.08 mm), elongated and posteriorly widened ( Fig. 6A–C ). Head tubular, slender, elongated, head and neck together much longer than pronotum ( Fig. 6A, B ); anteocular area of head elongate-conical; anteclypeus cylindrical and prominent; postocular area of head weakly globose, distinctly wider than anteocular area, shorter than anteocular area, constricted behind compound eyes, with a wide and deep interocular sulcus; neck long ( Fig. 6D, E ). Compound eyes protruding laterally, nearly globose, with posterior margin sub-straight, oblique with respect to ventral margin of head; lateral ocelli produced, slightly elevated behind interocular sulcus, separated from each other; interspace between lateral ocelli wider than distance between compound eye and lateral ocellus ( Fig. 6D, E ). First visible labial segment slightly thicker and much shorter than second segment, longer than anteocular area of head, not extending beyond level of middle of compound eye when labium laid backward ( Fig. 6D ); proportional average length of first to third visible labial segments 2.4:3.7:0.6. Scape about 1.6 times as long as head, about 2.5 times as long as pedicel, almost as long as second flagellomere; first flagellomere slightly shorter than pedicel and about 1/3 times as long as second flagellomere; proportional average length of scape, pedicel, first and second flagellomeres 7.0:2.9:2.3:6.8. Collar thick in dorsal view, with anterolateral angle roundly produced anteriorly; anterior pronotal lobe small, hemisphered and bulged, smooth, deeply depressed at base; posterior pronotal lobe rugulose and punctured, shallowly depressed on disc, with slightly swollen anteromedial elevation (never sulcate or concave); humerus bluntly triangular, with round apex; posterior margin of pronotum weakly concave, but slightly convex centrally; posterior angles round, slightly exceeded to posterior margin of pronotum ( Fig. 6F ). Scutellum triangular, somewhat triangularly depressed basally, apically produced with a scutellar spine, and sloping downward, posterior apex round ( Fig. 6F ); scutellar spine sub-vertical, short or almost tubercle-liked (0.44–1.21 mm), not bifid at apex ( Fig. 6B ). Femora elongated, slender but stout, moderate subnodulose apically; tibiae slender and elongated. Hemelytra surpassing beyond apex of abdomen when fully closed, 0.7 times as long as body length ( Fig. 6A ); discal cell nearly diamond-shaped, longer than width ( Fig. 6G ); Sc 0.8 times as long as hemelytron length, 1.4 times as long as R + M ( Fig. 6G ). Hind wing about 3.0 times as long as maximum width ( Fig. 6H ). Laterotergites much dilated and ascending with segmental incisures, posto-lateral margin of each laterotegite slightly produced than antero-lateral margin of following laterotegite ( Fig. 6A–C ). Pygophore ovoid ( Fig. 7B–D ); median process of pygophore (mpp) posteriorly produced, 0.52 times as long as wide in dorsal view, with apical margin convex, distinctly produced a round apex, apicolateral corner sub-round, distinctly produced posterolaterad ( Fig. 7B–E ); paramere long, slender, clavate, somewhat incurved and larger in apical part, with round apex ( Fig. 7F, G ). Aedeagus in dorsal view ovoid, dorsally sclerotized, and in lateral view long and narrow ( Fig. 7H ); articulatory apparatus (aa) in ventral view with basal plate arms relatively slender and jointly forming a V-shape, and in lateral view arched strongly ( Fig. 7H, I ); dorsal phallothecal sclerite (dps) in lateral view with posteromedian weakly produced ( Fig. 7I ); spoon-like sclerites (sps) largely anteriorly produced, hyaline and glabrous ( Fig. 7H, I ); membranous sac-like lobes almost disappeared ( Fig. 7H ); distal dorsal lobe of endosoma (ddl) round and weakly bulged, with two very large and long horn-shaped prickles centrally, surrounded by large prickles ( Fig. 7H–K ).

Vestiture. Body clothed with pale, shining griseous, slender setae. Head covered with very short bent slender setae, interleaved with short erect slender setae; labium almost glabrous except base of first visible segment with a few tiny slender setae ( Fig. 6D, E ). Scape and pedicel covered with short slender sub-erect setae; remaining antennae covered with short vertical setae, denser toward tip. Collar, anterolateral angles with tiny bent setae abundantly; anterior pronotal lobe with some rows of tiny bent setae, somewhat interleave with slender erect setae; posterior pronotal lobe covered with short slender setae and posteriorly cover with slender setae; scutellum densely covered with long, slender, vertical, erect black setae ( Fig. 6F ). Coxae and trochanters covered with short bent setae; femora, tibiae, and tarsi densely covered with long, slender, erect setae. Coria and clavus densely covered with short bent setae. Abdominal mediotergites sparsely covered with slender erect setae; lateral margins of laterotergites densely covered with short erect setae; abdominal sternites and laterotergites covered with short oblique cream-yellow setae, somewhat interleaved with long slender erect setae. Male genitalia pygophore ventrally covered with short slender bent setae and posteriorly densely covered with short and long slender setae ( Fig. 7B–E ); paramere almost glabrous except posterior apex densely covered with short and long thick erect setae ( Fig. 7F, G ).

Female description.

General external morphology similar to that of the male.

Coloration. Almost similar to male but differ in the following characters. Abdominal sternite VII yellow with dark brown suffusion near posterior margin, and blackish brown or back posterior margin; Gonocoxa VIII yellow with inner margin black; abdominal tergite IX and gonapophysis VIII black; abdominal laterotergite VIII orange or sanguineous ( Fig. 7A ).

Structure. Almost the same as male but larger than male and differ in the following characters. Body large-sized (22.18–24.87 mm), elongated, and somewhat robust. Head shorter than or almost as long as pronotum. Proportional average length of first to third visible labial segments 2.6:4.2:0.7. Scape about 1.9 times as long as head, about 2.4 times as long as pedicel, slightly longer than second flagellomere; first flagellomere slightly shorter than pedicel and about 1/3 times as long as second flagellomere; proportional average length of scape, pedicel, first and second flagellomeres 7.3:3.0:2.5:6.7. Abdominal laterotergite VIII with thin posterior margin, not exceed the posterior margin of abdominal tergite IX; abdominal sternite VII forming a semi-circular or wide sub-pentagonal median concavity, with posteromedian margin gently U-shaped, with inner posterolateral margin slightly concave; gonocoxa VIII subtriangular, produced mesad and forming a pointed apex at apical inner corner, and with inner margin weakly incurved in posterior 2/3; gonapophysis VIII subtriangular, posteriorly produced; abdominal tergite IX small ( Fig. 7A ).

Vestiture. Almost the same as male except for the following characters.Anterior 1/3 of gonocoxa VIII almost no setae; posterior 2/3 of gonocoxa VIII covered with short and long bent black setae; posterior margin of gonapophysis VIII densely covered with long bent black setae; abdominal laterotergite VIII and abdominal tergite IX covered with short and long bent black setae ( Fig. 7A ).

Measurements. All dimensions are given in mm. Holotype (♂): BL 18.89; HL 3.75; AoL 1.73; AoW 0.87; PoL 1.12; PoW 1.27; NL 1.17; OE 1.78; IE 0.70; ED 1.09; OD 0.22; OCD 0.36; COD 0.20; R1L 2.50; R2L 3.88; R3L 0.61; A1L 7.79; A2L 2.88; A3L 2.30; A4L 7.06; PnL 3.62; PnW 4.26; APL 1.31; PPL 2.30; SPL 0.46; HeL 13.84; HeW 4.58; Sc 10.23; R+M 7.38; HWL 9.63; HWW 3.17; AFL 7.09; ATL 8.29; MFL 6.34; MTL 7.89; PFL 8.41; PTL 11.08. Paratype (♂): BL 19.08; HL 3.61; AoL 1.62; AoW 0.88; PoL 1.10; PoW 1.23; NL 1.14; OE 1.69; IE 0.69; ED 1.03; OD 0.19; OCD 0.46; COD 0.20; R1L 2.32; R2L 3.73; R3L 0.60; A1L 6.82; A2L 3.08; A3L 2.15; A4L 6.60; PnL 3.52; PnW 4.22; APL 1.20; PPL 2.31; SPL 1.21; HeL 13.49; HeW 4.04; Sc 9.95; R+M 6.00; AFL 7.72; ATL 8.19; MFL 6.25; MTL 7.63; PFL 8.10; PTL 10.44. Paratype (♀): BL 22.18–24.87; HL 3.81–4.23; AoL 1.85–2.04; AoW 0.94–1.04; PoL 0.95–1.23; PoW 1.25–1.46; NL 1.35–1.42; OE 1.73–1.87; IE 0.76–0.84; ED 1.04–1.10; OD 0.21–0.28; OCD 0.45–0.58; COD 0.18–0.21; R1L 2.50–2.72; R2L 4.03–4.36; R3L 0.63–0.81; A1L 6.83–7.82; A2L 3.04–3.08; A3L 2.26–2.66; A4L 6.47–7.03; PnL 3.71–4.74; PnW 5.14–5.63; APL 1.03–1.45; PPL 2.69–3.27; SPL 0.96–1.53; HeL 16.05–18.06; HeW 4.67–5.13; Sc 11.69–12.98; R+M 7.93–8.83; AFL 7.33–8.08; ATL 8.58–9.00; MFL 6.19–6.71; MTL 7.89–8.40; PFL 8.11–9.22; PTL 11.37–12.05.

Distribution. Vietnam, Middle and Southern Vietnam (Thua Thien Hue, Quang Nam, Binh Dinh, Gia Lai, Dak Lak Provinces).

Type locality. Vietnam, Thua Thien Hue , Bach Ma National Park .

Etymology. The specific epithet refers to its occurrence in Thua Thien Hue, the North Central Coast region, the Central of Vietnam; an adjective.

Figures

FIGURE 4. Body in dorsal view of two new morphospecies, α and β. A, Sycanus thuathienhuensis Truong & Ha, sp. nov. (= α), paratype, ♂, TXL2024-009; B, S. taynguyenensis Truong & Ha, sp. nov. (= β), holotype, ♂, NDD2019-285.

FIGURE 6. Sycanus thuathienhuensis Truong & Ha, sp. nov., holotype, ♂, TXL2024-012. A, body in dorsal view; B, body in lateral view; C, body in ventral view; D, head in lateral view; E, head in dorsal view; F, pronotum and scutellum in dorsal view; G, right hemelytra; F, right hind wing.

FIGURE 7. Sycanus thuathienhuensis Truong & Ha, sp. nov., A, female genitalia in ventral view, paratype, ♀, NDD2022-063; B–K, male genitalia, holotype, ♂, TXL2024-012. B–E, pygophore with parameres; B, dorsal view; C, lateral view; D, ventral view; E, caudal view; F–G, left paramere; F, dorsal view; G, lateral view; H–J, aedeagus with endosoma semi-everted dorsal view; H, dorsal view; I, lateral view; J, ventral view; K, distal dorsal lobe of endosoma (ddl).