Rhagovelia borbei, V & Zettel, 2023

V, Clister & Zettel, Herbert, 2023, Contribution to the knowledge of aquatic Heteroptera (Hemiptera) of Greater Sulu, Philippines, Linzer biologische Beiträge 54 (2), pp. 609-620 : 612-616

Rhagovelia borbei nov.sp. ( Figs 1–4 )

E t y m o l o g y. The new species is dedicated to Mr. Ian Borbe, who ensured the safety of the first author during his stay in the Sulu Archipelago.

T y p e m a t e r i a l. Holotype (apterous male) and paratypes (1 apterous male, 5 apterous females, 2 macropterous males, 3 macropterous females) from locality PA09.

D i a g n o s i s. Gracile species; body length (excluding wings) ca. 3.7–4.5 mm. Pronotum of apterous morph with a lobe covering mesonotum. Juga at posterior region, a broad stripe anteriorly on propleuron and entire proepisterna with small black spinulae. Colour chiefly black. Head black, except labrum, juga, and rostrum (without apex) yellow. Prothorax yellow, but pronotal lobe except the narrow yellow margins black to blackish brown; coxae, trochanters, base and underside of pro- and metafemur yellow. – Male. Hind leg ( Fig. 1 ): Metatrochanter with a few short denticles. Metafemur strongly enlarged (much less so in winged specimens); flexor side at basal third with dense, regular row of short denticles; distal two thirds with row of ca. 11 teeth of decreasing length; a broad area anterior (ventral) of these structures with irregular short dentition. Metatibia almost evenly curved, flexor side densely dentate, with an apical and a subapical tooth. Genitalia of moderate size. Paramere ( Fig. 2 ) small, with almost straight distal part bearing a small, ventrally curved, blunt lobe. Proctiger slender, with weakly protruded lateral wings. – Female. Basal half of metafemur without or with 1–5 minute teeth; distal row consisting of 6–9 teeth of decreasing length, the first one usually strongly curved. Gonocoxa 1 with straight ventral outline. Proctiger directed posteriorly. Long, black pilosity on posterior part of gonocoxa 1, posterodorsal corner of sternum 7, laterotergite 8, and sides of tergite 8. – Apterous female. Abdomen ( Figs 3, 4 ) curved dorsad, sides strongly converging anteriorly, very narrow posteriorly; posterior sterna curved dorsally over tergites, sides of sternum 7 touching in middle and covering tergite 7, or nearly so.

D e s c r i p t i o n o f a p t e r o u s m a l e. Measurements of holotype: Body length 3.72; maximum body width (at metapleura) 1.33. Head length 0.35, width 0.80; minimum eye distance 0.18. Pronotum length 0.85, width 1.22. Lengths of antennomeres, I 0.84, II 0.57, III 0.57, IV 0.49. Lengths of leg segments: profemur 1.02, protibia 1.14, protarsus 0.03 + 0.03 + 0.24, mesofemur 1.73, mesotibia 1.38, mesotarsus 0.07 + 0.44 + 0.72, metafemur 1.66, metatibia 1.60, metatarsus 0.07 + 0.11 + 0.37.

Measurements of paratype (n = 1): Body length 3.66; maximum body width (at metapleura) 1.31. Head width 0.79. Pronotum length 0.84, width 1.21.

Colour: Chiefly black. On head, labrum, juga, and rostrum (except apex) yellow. First antennomere with yellow basal half. Prothorax mainly yellow; yellow stripe at foremargin of pronotum uninterrupted (or with faint brownish midline), laterally narrowly connected with yellow propleura; pronotal lobe except the narrow margins black to blackish brown. Meso- and meta-acetabula partly yellow. All coxae and trochanters yellow; base and underside of pro- and metafemur yellow; mesofemur with a small yellowish-brown dot at base. Laterotergites and sterna laterally with narrow yellow stripe. Medial part of sternum 7, ventral parts of segment 8, and genitalia brown.

Pilosity: Dorsum of head and thoracic nota with long, curved, black setae; sides of thorax almost bare. Abdominal tergites with rather long black oblique setae. Laterotergites with short pilosity, but each with a single long seta close to apex of margin. Sterna with numerous long setae; ventral part with dense brush of oblique setae, notably on sides of sternum 7.

Structures: Head broader than anterior margin of pronotum. Juga flat, strongly inclined, moderately broad, apically with spinulae. Pronotum long, with a well-developed pronotal lobe, along midline about 2.5 times as long as head. Mesonotum not visible. Proepisterna bearing numerous small black spinulae. Propleuron with a broad anterior area bearing numerous spinulae, with dense row of black pits near hind margin; mesopleuron with scattered similar pits, metapleuron with few pits.

Profemur on extensor side lacking distinct concavity. Coxae and trochanters lacking black spinulae. Metatrochanter with several small denticles of different size. Hind femur ( Fig. 1 ) strongly enlarged, dentition on flexor side rich: at basal third with straight, dense, almost regular row of ca. 20 minute denticles; distal two thirds with row of ca. 11 teeth of decreasing length, the first one not conspicuously long; a broad area anterior (ventral) of these structures with irregular short dentition. Metatibia almost evenly curved, flexor side densely dentate, with some longer teeth in apical fourth, with an apical and a subapical tooth.

Laterotergites strongly inclined. Anterior tergites strongly, posterior tergites slightly convex. Tergite 7 about 1.5 times as long as tergite 6, and 0.8 times as long as broad, shiny. Dorsal part of segment 8 similarly shiny. Sterna without median carina; sternum 7 posteriorly with large, hairless, half-ovate depression. Proctiger slender, with hardly protruded lateral wings. Paramere ( Fig. 2 ) small, with almost straight distal part bearing a small, blunt, ventrally curved apical lobe.

D e s c r i p t i o n o f a p t e r o u s f e m a l e. Measurements (n = 5): Body length 3.98–4.15; maximum body width (at metapleura) 1.41–1.46. Head width 0.78–0.80. Pronotum length 0.82–0.93, width 1.26–1.29.

Colour: similar to apterous male. Yellow stripe laterally on sterna posteriorly narrowed and rather brownish, almost lacking on sternum 7; yellowish-brown colour of medial parts of abdominal sterna more extended anteriorly in most specimens.

Pilosity of head and thorax similar as in male, on abdomen largely reduced except on apex. Tergites 1–2 with short, grey, appressed pubescence; tergite 1 with some black standing setae; tergites 3–6 bare; tergite 8 completely beset with long black, chiefly posterolaterally directed setae. Laterotergites at margin with stripe of short pubescence, mesally bare. Sterna in middle with oblique setae, sterna 3 and 4 with conspicuous tufts of long setae, the following ones with scattered setae of decreasing length; posterodorsal corners on sternum 7 with tufts of long black setae. Gonocoxa 1 with short pilosity and dense, long setae in front of hind margin.

Structures: Head and thorax similar as in apterous male. Fore and middle leg (including mesofemur) unmodified. Metatrochanter with one, rarely up to four short denticles. Metafemur much more slender than in male, dentition of flexor side less developed: basal half of metafemur without dentition or with 1–5 minute teeth, a basal row of minute denticles, as present in male, lacking; distal row consisting of 6–9 teeth of decreasing length, the first one usually strongly curved; more anteriorly (ventrally) 4–5 denticles, more or less arranged in a row. Metatibia almost straight, dentition on flexor side much weaker than in male.

Abdomen ( Figs 3, 4 ) elongated and curved dorsad; sides strongly converging anteriorly, very narrow posteriorly. Tergites 1–2 strongly convex, the following ones flat and narrow; tergite 5 almost twice as long as anteriorly wide; tergite 6 almost triangular (with very narrow hind margin); tergite 7 usually totally covered by sterna; tergite 8 directed posteriorly. Posterior sterna curved dorsally over tergites, sides of sternum 7 touching in middle and covering tergite 7, or nearly so; connexival corner strongly protruded, its apex rounded. Gonocoxa 1 with straight ventral outline; surface slightly concave. Proctiger directed posteriorly.

D e s c r i p t i o n o f m a c r o p t e r o u s m a l e. Measurements(n=2):Body length 3.82–3.87; maximum body width (at pronotum) 1.51–1.58. Head width 0.80–0.81. Pronotum length 1.39–1.42.

Colour: Similar to apterous male. Forewing blackish, with 1–2 whitish streaks at base.

Pilosity on head, thorax, and sterna similar as in apterous male. Basal and lateral (anterior) veins of forewing with rows of rather short setae.

Structures: Head and thorax sides similar as in apterous male. Pronotum large, with protruding humeri. Forewing with four closed cells reaching distal fourth; dealate specimens unknown. Metafemur distinctly more slender and with narrower ventral area of denticles when compared to apterous male, basal row of denticles slightly longer; distal row of teeth of similar armature. Metatibia moderately curved, with moderate dentition at flexor side, subapical tooth indistinct.

D e s c r i p t i o n o f m a c r o p t e r o u s f e m a l e. Measurements(n=3): Body length 3.98–4.45; maximum body width (at pronotum) 1.44–1.63. Head width 0.78– 0.83. Pronotum length 1.38–1.50.

Colour: Similar to apterous female. Forewing blackish, with whitish streaks at base. Yellow lateral stripes on posterior sterna not reduced.

Pilosity: Setae on abdomen similar as in apterous female. Setae on forewing veins as in macropterous male.

Structures: Head and thorax sides similar as in apterous female. Pronotum and forewings as in macropterous male. Hindleg structures similar as in apterous female. Abdomen broad, not upcurved; connexiva subparallel; sterna not curved over tergites; connexival corner more weakly protruded. Tergite 8, gonocoxa, and proctiger as in apterous female.

C o m p a r a t i v e n o t e s. Rhagovelia borbei nov.sp. is a species of the R. papuensis group, R. cotabatoensis subgroup (sensu ZETTEL 1996). The strongly converging connexiva of the apterous female are similar to that of R. cotabatoensis HUNGERFORD & MATSUDA, 1961 and R. graindli ZETTEL, 2012 , but the dense, long pilosity at the apex of the female’s abdomen immediately distinguishes the new species. Females of R. tsouloufi NIESER, ZETTEL & CHEN, 1997 from Salebabu Island (Talaud Archipelago, Indonesia) have a similar pilosity, but apterous specimens can be immediately distinguished from R. borbei nov.sp. by long, erect setae on connexivum 6, a straight, not upcurved abdomen, and a petiolate metafemur; in addition, this species lacks black spinulae on juga and proepisterna (males and females) (compare to description in NIESER et al. 1997). In males, the ventroapical lobe of the paramere of this new species differs from the corresponding hook- or lobe-like structures of R. cotabatoensis and R. graindli .

Figures

Figs 1-4: Rhagovelia borbei nov.sp.: (1) hind leg of apterous male (holotype). (2) Left paramere of male (holotype). (3) Abdomen of apterous female (paratype), dorsal aspect. (4) Same, lateral aspect. (Pilosity omitted in 1, partly omitted in 3 and 4.)