Sirthenea (Sirthenea) obscura ( Stål, 1866 )

Chłond, Dominik, 2018, A taxonomic revision of the genus Sirthenea (Hemiptera: Heteroptera: Reduviidae) of the Old World, Zootaxa 4520 (1), pp. 1-85 : 69-76

Sirthenea (Sirthenea) obscura ( Stål, 1866)

( Figs. 144–152 , 182 , 189 , 208 , Map 13)

Sirthenea obscura Stål, 1866: 253 . Syntype (s), (♂): Sidney: Australia; NHRS.

Peirates obscurus: Walker (1873: 127) .

Sirthenea glabra Walker, 1873: 129 . Syntype (s) (♂): Australia; NHMUK. Syn. nov.

Type material examined: Sirthenea obscura Stål, 1866 . Syntype, Ƌ: Sidney [printed]; Stevens [printed]; obscura Stål [handwritten]; Typus [printed on red label] (NHRS). Sirthenea glabra Walker, 1873 . Syntype, Ƌ: Type [printed on round label with green margin]; 58–124 / Australia. [printed]; 111. Pirates glaber. [printed] (NHMUK).

Other material examined: Ƌ: Kanangra Walls / 60 km SE Oberon / 1000 m 28.11.1989 [printed]; Australia NSW / Kanangra Nat. Park / P. Oosterbroek / & C. Hartveld [printed] ( RMNH). Ƌ : Australia N.S. W. / Cabramatta. / 15.xi.1965 / M.I.Nikitin. / B.M. 1966–97. [printed] ( NHMUK) .

Diagnosis. This species can be easily distinguished from S. laevicollis , also distributed in the Australian Region, by the lack of fossula spongiosa on middle tibia, eye wider than synthlipsis, U-shape posterior margin of an eye in lateral view ( Fig. 189 ), distinct sulci on pronotum, smooth posterior pronotal lobe, spiracles III–IV placed close to ventral connexival suture, different shape of right paramere, and distinctly thicker median process of pygophore.

Redescription: Color: All body dark brown except slightly paler posterior part of posterior pronotal lobe, apical part of corium, coxa, second and third visible labial segments. Dense group of setae on mid tibia pale ( Figs. 144 , 208 ).

Structure: Body medium sized to large, slender. Head, pronotum and scutellum shiny. Head with scarce and relatively long, setae. Anteocular part of head 3.1–3.5 times as long as postocular part. Clypeus distinctly elevated. Eyes globular and large (wider than synthlipsis in dorsal view, reaching dorsal margin of head and reaching or surpassing ventral margin of head in lateral view). Posterior margin of an eye U-shaped in lateral view ( Fig. 189 ). Ocelli relatively large and not pigmented, placed on robust tubercles. Dorsal surface of antennifers corrugated. Scape club-shaped not reaching or almost reaching apex of head covered by various sized (mostly long), semierect and erect setae. Pedicel robust, covered by very dense, short and several relatively long, erect setae and with 6 trichobothrial setae ( Fig. 182 ). Basiflagellum gradually thiner into apex covered by dense and various sized, erect setae. Second visible labial segment enlarged basally, reaching over posterior margin of an eye in lateral view. Third visible labial segment relatively long and very thin. Ventral surface of head flat or delicately inwardly curved, with two long erect setae on height of posterior margin of an eye. Ridges of proepisternum and proepimeron connected in entire length. Anterior pronotal lobe relatively wide, covered with scarce, very long, trichobothrial setae placed on sulci. Latero-internal sulci distinctly wrinkled longitudinally. Apodeme depression of anterior pronotal lobe short and wide, covering 1/3 of basal part of median sulcus, with very distinct irregular sculpturation. Transversal suture of pronotum irregular in shape. Posterior pronotal lobe delicately wrinkled in middle part, connected with transversal suture. Posterior margin of posterior pronotal lobe only delicately curved. Margins of pronotum covered by relatively long and dense setae. Metapleura with two complete ridges. Margins of scutellum distinctly enlarged and shiny, covered by long and very long setae. Central part of scutellum distinctly depressed and granulated, apex relatively long. Femur, tibia and tarsus covered by relatively long and erect setae. Hemelytron slender, covered by short and medium-sized setae, very dense on costal margin. Corium and membrane dull. Membrane delicately wrinkled. Abdomen beneath sternites wrinkled transversally in lateral parts, covered by long, semierect setae. Spiracles III–IV placed close to ventral connexival suture.

Genitalia: Median process of pygophore strongly elongated and stout, gradually narrowed to apex ( Fig. 145 ). Both parameres subtriangular and large with dense and relatively long setae on outer side and inner side with sharp apices ( Figs. 146–149 ). Apical part of left paramere distinctly elongated vertically in inner and outer views ( Figs. 146, 147 ). Aedeagus visibly curved in dorsal view ( Fig. 152 ). Pedicel stout and relatively short, placed assymetrically and bent laterally ( Figs. 150–151 ). Basal plates relatively long and stout ( Fig. 152 ). Dorsal phallothecal sclerite relatively thin with enlarged tongue-like apex ( Figs. 150, 152 ).

Measurements (in mm): Body length: 18.8–19.4; maximum width of abdomen: 3.7–4.9; head length: 3.5– 3.4; head width: 2.1–2.2; length of anteocular part: 1.7; length of postocular part: 0.5–0.6; length of synthlipsis: 0.6; interocellar distance: 0.4–0.5; length of antennal segments I:II:III:IV: 1.0–1.1: 2.1–2.3: 1.9–2.3: missing; length of visible labial segments I:II:III: 0.9: 2.3: 1.3–1.4; maximum length of anterior pronotal lobe: 3.0–3.1; maximum length of posterior pronotal lobe: 2.2–2.7; maximum width of anterior pronotal lobe: 3.0–3.2; maximum width of posterior pronotal lobe: 4.1–4.5; length of scutellum: 1.8; length of hemelytron: 13.8–13.9.

Female: Unknown.

Distribution: Australia (Sydney) (Map 13: red squares).

Figures

FIGURE 144. Sirthenea obscura (Stål, 1866)—dorsal habitus.

FIGURES 145–152. Sirthenea obscura (Stål, 1866): 145—pygophore, dorsal view; 146—left paramere, inner view; 147—left paramere, outer view; 148—right paramere, lateral view; 149—right paramere, outer view; 150—phallus, right lateral view; 151—phallus, left lateral view; 152—phallus, dorsal view.

FIGURES 169–182. Trichobothrial setae on pedicel: 169—Sirthenea africana Distant, 1903; 170—S. flaviceps (Signoret, 1860); 171—S. picescens Reuter, 1887; 172—S. rodhaini Schouteden, 1913; 173—S. caiana Chłond, 2008; 174—S. dimidiata Horváth, 1911; 175—S. flavipes (Stål, 1855); 176—S. kali sp. nov.; 177—S. nigronitens (Miller, 1958); 178—S. nitida Chłond, 2008; 179—S. nigra Cai & Tomokuni, 2004; 180—S. setosa sp. nov.; 181—S. laevicollis Horváth, 1909; 182—S. obscura (Stål, 1866).

FIGURES 188–192. 188—Ridges of metapleura of Sirthenea caiana Chłond, 2008; 189—U-shape posterior margin of an eye of S. obscura (Stål, 1866); 190—S-shape posterior margin of an eye of S. flaviceps (Signoret, 1860); 191—Ridges of proepisternum and proepimeron of S. africana Distant, 1903; 192—Ridges of proepisternum and proepimeron of S. nigronitens (Miller, 1958).

FIGURES 205–208. Color figures of habitus: 205—Sirthenea nitida Chłond, 2008; 206—S. nigra Cai & Tomokuni, 2004; 207—S. setosa sp. nov.; 208—S. obscura (Stål, 1866).