Hebrus (Hebrus) kanyukovae, Kment & Carapezza, 2022

Kment, Petr & Carapezza, Attilio, 2022, Heteroptera (Hemiptera) of the Socotra Archipelago I: Introduction, Nepomorpha, Gerromorpha and Leptopodomorpha, Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 62 (2), pp. 475-519 : 489-493

Hebrus (Hebrus) kanyukovae sp. nov.

( Figs 13–15 , 17–24 , 26–31 )

Type material. HOLOTYPE: ♂ (ma), ‘ YEMEN, SOCOTRA Island / Halla area, ARHER freshwater / spring in sand dune, Tamarix / nilotica shrubs, 9-10.+ 15.vi.2012 / 12°33.0′N, 54°27.6′E, 5 m [p] // SOCOTRA expedition 2012 / J. Bezděk, J. Hájek, V. Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg. [p] // ♂ [p] // HOLOTYPUS / HEBRUS (Hebrus) / KANYUKOVAE / sp. nov. / det. Kment & Carapezza 2022 [p, red label]’ ( NMPC) . PARATYPES: SOCOTRA: Hallah Arhar [= Halla area, Arher ] (spring), 15 m, 12°33.0′N 54°27.6′E, 11.xi.2010, 1 ♀ (ma), J. Bezděk lgt. ( MMBC), 1 ♂ 1 ♀ (ma), J. Hájek lgt. ( NHMW: in pure ethanol); Halla area, Arher (12°33′00ʺN 54°27′36ʺE), freshwater spring in sand dune, 5 m a.s.l., 9.–10.vi.2012, 1 ♂ 7 ♀♀ (ma), Socotra expedition 2012: J. Bezděk, J. Hájek, V. Hula, P. Kment, I. Malenovský, J. Niedobová & L. Purchart lgt. (5 ♀♀ NMPC, 1 ♀ ACPI, 1 ♀ NHMW); Dixam plateau, wadi Zerig (12°29′36ʺN 53°59′30ʺE), pool at road bridge, Juncus marsh, 655 m a.s.l., 13.–14.vi.2012, 1♀ (ma), Socotra expedition 2012: J. Bezděk, J.Hájek,V.Hula, P.Kment,I. Malenovský, J. Niedobová & L. Purchart lgt. ( NMPC). All the paratypes bear the following label: ‘ PARATYPUS / HEBRUS (Hebrus) / KANYUKOVAE / sp. nov. / det. Kment & Carapezza 2022 [p, red label]’.

Additional material examined. Dixam plateau, wadi Zerig (12°29′36ʺN 53°59′30ʺE), pool at road bridge, Juncus marsh, 655 m a.s.l., 13.–14. vi.2012, 1♀ (ma), Socotra expedition 2012:J. Bezděk, J. Hájek,V.Hula, P. Kment, I. Malenovský, J. Niedobová & L. Purchart lgt.( NMPC); Halla area,Arher (12°33′00ʺN 54°27′36ʺE), freshwater spring in sand dune, 5 m a.s.l., 9.–10.vi.2012, 1 L, Socotra expedition 2012:J. Bezděk, J. Hájek, V. Hula, P.Kment, I. Malenovský, J. Niedobová & L.Purchart lgt.( NMPC).

Description. Colouration ( Figs 13–14 ). Head and thorax yellowish brown (holotype) to brown (paratypes), posterior areas of head and pronotum usually slightly paler. Bucculae, labium, acetabula, and longitudinal carinae forming rostral groove yellowish to pale brown, always paler than dorsal body surface. Antennal segments I and II yellowish to pale brown, apex of I and ca. apical quater to third of II brown, segments III, IVa and IVb brown. Legs yellowish, apices of femora, and bases and apices of tibiae and tarsi infuscated with brown ( Fig. 13 ). Veins of corium dark brown; basal portion of clavus milky white, posterior portion of clavus and membranous portion of corium beige, without sharp transition between white and beige areas. Membrane brown with three oval whitish spots ( Fig. 13 ) – one approaching each anterolateral angle, third situated medially behind middle of membrane. Abdomen black.

Structure. Body elongate ( Figs 13–14 ), about 2.3 times longer than wide across humeral angles. Vertex with median sulcus developed ( Figs 17–18 ). Bucculae ventrally straight, posterior margin truncate ( Fig. 19 ). Labium reaching metacoxae. Ratio of lengths of antennal segments I– IVb (holotype): 1.79: 1.29: 1.50: 1.00: 1.36. Posterior portion of metanotal elevation (‘scutellum’) slightly turned upwards, more or less pentagonal, apical marging varying from widely rounded (holotype, Figs 17, 20 ) to more or less triangular ( Figs 22–23 ), always bearing small apical process medially ( Figs 17, 20–23 ); disc of metanotal elevation depressed medially, with median carina well developed in posterior half but weakly developed or obsolete in anterior half ( Figs 17, 20–23 ). Macropterous, hemelytra of both sexes nearly reaching apex of abdomen, only posterior margin of last tergite free ( Figs 13–14 ). Metafemora distinctly curved in male ( Figs 13 , 27 , 29 ), only slightly curved in females ( Fig. 14 ). Metatibiae of males straight, not swollen, basally attenuated, their ventral surface straight in posterior three quaters of their length ( Figs 26–29 ). Paramere as in Figs 30–31 , dorsal surface bearing dense long setae and one pointed tubercle medially, pointed apex of large lateral process slightly turned upwards.

Pubescence whitish, on head and pronotum very short and adpressed, apparent only under large magnification; corium and beige posterior portion of clavus with longer, adpressed, well visible setae. Ventral surface of body covered with short silver setae, somewhat longer on apex of abdomen. Antennae and legs with short, semierect, yellowish setae. Male metatibiae with one row of about 13 long, stout, erect setae medially on dorsal surface, setae directed posteriad, middle ones longest ( Figs 26–29 : ds), and one row of long but finer and denser, semierect setae distinctly longer than metatibia diameter on inner surface starting ca. in basal quater and shortening in apical quater ( Figs 29–32 : is).

Measurements. Males (n = 2; holotype / paratype). Body length: 1.77 / 1.66; pronotum: anterior width (across anterolateral angles) 0.39 / 0.39), humeral width (across humeral angles) 0.78 / 0.72); length of antennal segments: I – 0.25 / 0.23, II – 0.18 / 0.16), III – 0.21 / –, IVa – 0.14 / –, IVb – 0.19 / –; metafemur: length 0.48 / 0.48; metatibia: length 0.62 / 0.58; metatarsus: length 0.21 / 0.23.

Females (n = 8; median (minimum–maximum)). Body length: 1.85 (1.73–1.95); pronotum: anterior width 0.40 (0.39–0.43), humeral width 0.81 (0.78–0.90); length of antennal segments: I – 0.20 (0.19–0.23), II – 0.16 (0.16–0.18), III – 0.19 (0.19–0.21), IVa – 0.16 (0.14–0.16), IVb – 0.19 (0.18–0.21).

Variability. One female from the locality wadi Zerig ( Fig. 15 ) differs in posterior margin of metanotal elevation more triangulate ( Fig. 24 ), resembling those of H. campestris Linnavuori, 1971 , and is also slightly larger than the remaining specimens (body length 2.07 mm; pronotum: anterior width 0.45 mm, humeral width 0.96 mm; length of antennal segments I – 0.25, II – 0.19, III, IVa and IVb missing). Though we tentatively identify the female as H. kanyukovae , we leave it outside the type series.

Differential diagnosis. Considering the fauna of the genus Hebrus Curtis, 1833 in the regions showing some biogeographical relationships to Socotra, there are 84 described species-group taxa accommodated in six subgenera ( Hebrus s. str. – 59 species and subspecies, Hebrusella Poisson, 1944 – 13 species and subspecies, Paratimasiellus Poisson, 1956 – 1 species, Paratimasius Poisson, 1952 – 3 species, Subhebrus Poisson, 1956 – 1 species, Timasielloides Poisson, 1952 – 7 species and one unavailable form): Africa with 73 species ( POISSON 1934b, 1944, 1949b, 1950b, 1951b, 1952a, 1953, 1955b, 1956a,b, 1957a,c, 1959a,b, 1960a,b, 1964a,b; HOBERLANDT 1951a; LINNAVUORI 1971, 1973a, 1981; COBBEN 1982a,b; COBBEN & LINNAVUORI 1983; J. T. POLHEMUS 1989; D. A. POLHEMUS 1992; KMENT et al. 2016), Arabian Peninsula, Near East and Iran with 8 species (three of them also occurring in north-east Africa) ( BROWN 1951; LINNAVUORI 1971, 1986a, 1994b; ANDERSEN 1995; KANYUKOVA 1997; KMENT & KANYUKOVA 2010; AUKEMA et al. 2013), and India and Sri Lanka with 7 species ( DISTANT 1909a; PAIVA 1919; ANDERSEN 1995; ZETTEL 2000, 2002, 2006; THIRUMALAI 2002).

Using the key to the subgenera by ANDERSEN (1981) the species belong to Hebrus s. str., being characterized by metanotal elevation subtriangular with posterior margin straight, antennal tubercles not produced externally, and false joint structure of antennal segment IV in form of constricted zone. We compared the new species with the original descriptions and redescriptions of the 57 species of Hebrus s. str. (see references above) but none of them fits. Hebrus kanyukovae sp. nov. is distinguished from all the compared species by the following combination of characters: colouration of body yellowish brown to brown; macropterous; basal half of clavus milky white, posterior one beige, not divided by sharp transition; metanotal elevation trapezoid, posterior margin widely rounded to shortly triangular, medially not incised but bearing short rectangular process ( Figs 17, 20–23 ); male metafemora only slightly curved; male metatibiae straight, not swollen, bearing one row of stout setae on dorsal surface and one row of finer setae on inner surface ( Figs 26–29 ).

There are two species sharing the double row (dorsal and inner) of long setae on male metatibia in the Palaearctic, H. pilipes Kanyukova, 1997 distributed from Crimea and Turkey to Afghanistan, Tajikistan and China: Xinjiang ( KANYUKOVA 1997, KMENT & JINDRA 2006, KMENT & KANYUKOVA 2010, FENT et al. 2011, KANYUKOVA et al. 2016, KMENT et al. 2016), and H. pusillus arabicus Linnavuori, 1971 from Sudan, Iran, Iraq, Oman, Saudi Arabia, United Arab Emirates, and Yemen ( LINNAVUORI 1986a, 1994b; LINNAVUORI & VAN HARTEN 1997 , 2002a; LINNAVUORI et al. 2011; KMENT et al. 2016). Hebrus pilipes differs in presence of sharp horizontal transition line between white and brownish portions of clavus, male metafemora more curved (see KANYUKOVA 1997: fig. 3), male metatibiae swollen in anterior third, with their inner surface undulated, bearing several rows of long erect setae (see KANYUKOVA 1997: fig. 9), and metanotal elevation posteriorly straight, without apical rectangular tubercle, with median carina developed throughout the central depression (see KANYUKOVA 1997: fig. 18). Hebrus pusillus arabicus generally shares the same colour pattern, but differs in having metatibia distinctly curved slightly behind its middle, and long setae on metatibia shorter, especially concerning the inner row, whose setae are about as long as metatibia diameter. Etymology. We dedicate the species to Elena V. Kayukova (Zoological Museum, Far Eastern State University, Vladivostok, Russia), an eminent specialist in aquatic and semiaquatic Heteroptera and author of an important revisional work on the genus Hebrus in the Palaearctic Region.

Habitat. At Arher, the species was collected by suction sampler from wet places with shortly grazed grasses on sand, surrounding a small brook situated among sand dunes and groups of Tamarix nilotica about 50 m from sea coast ( Fig. 49 ). In wadi Zerig, the species was collected at a large pool on shore with growth of Juncus socotranus ( Fig. 53 ). The type locality is situated in the coastal zone (5 m a.s.l.), wadi Zerig in medium elevation zone (655 m a.s.l.).

Distribution. Palaearctic Region: Socotra (this paper).

Figures

Figs 13–16. 13–14 – Hebrus kanyukovae sp. nov.: 13 – ♂, holotype (body length 1.77 mm); 14 – ♀, paratype, Arher (1.95 mm). 15 – Hebrus cf. kanyukovae, ♀, wadi Zerig (2.07 mm); 16 – Hebrus (Hebrus) sp., ♀, Tudhen (1.95 mm). (Orig. P. Kment).

Figs 17–25. 17–19 – Hebrus kanyukovae sp. nov., ♂, holotype: 17 – fore body, dorsal view (magnification 100×); 18–19 – head (18 – dorsal view, 230×; 19 – lateral view, 190×). 20–25 – metanotal elevation, dorsal view (250×): 20–23 – H. kanyukovae sp. nov.: 20 – ♂, holotype; 21 – ♂, paratype; 22–23 – ♀♀, paratypes, Arher; 24 – H. cf. kanyukovae, ♀, wadi Zerig; 25 – Hebrus (Hebrus) sp., ♀, Tudhen. Scale bars: 0.1 mm (Figs 18–25), 0.2 mm (Fig. 17). (Orig. P. Kment).

Figs 26–28. Hebrus kanyukovae sp. nov., ♂, metatibia: 26–27 – paratype (magnification: 26 – 270×, 27 – 200×), 28 – holotype (350×). Abbreviations: ds – dorsal setae, is – inner setae. Scale bars: 0.1 mm. (Orig. P. Kment).

Figs 29–31. Hebrus kanyukovae sp. nov., ♂: 29 – hind leg, schematic; 30–31 – paramere (30 – dorsal view, 31 – ventral view, setae omitted):Abbreviations: ds – dorsal setae, is – inner setae. Scale bars: 0.05 mm (Figs 30–31), 0.2 (Fig. 29). (Orig. P. Kment).

Figs 49–53.49 –Arher,a spring near the sea coast (5 m a.s.l.), habitat of Ochterus papaceki Kment & Carapezza,2020,Anisops debilis socotrensis Brown, 1956, Mesovelia vittigera Horváth,1895,Hebrus kanyukovae sp.nov.,Microvelia macani Brown,1953,Rhagovelia infernalis socotrensis Brown,1956 and Micracanthia ornatula (Reuter,1881).50– Wadi Madar (1,170 ma.s.l.), habitat of Anisops d.socotrensis, A.varius Fieber,1851,Mesovelia vittigera, Microvelia macani, and Rhagovelia i. socotrensis. 51 –Skand Mt.,helocreneunder the top (1,450 ma.s.l.), habitatof Microvelia gracillima Reuter,1882 andSaldula niveolimbata (Reuter, 1900). 52 – Tudhen, helocrene (1,135 m a.s.l.), habitat of Mesovelia vittigera, Hebrus sp., and Microvelia gracillima Reuter, 1882. 53 –Wadi Zerig with a large pool (655 m a.s.l.), habitat of Micronecta eupompe Hutchinson, 1930, Sigara hoggarica Poisson,1929,Anisops d.socotrensis, A.varius, Hebrus kanyukovae sp.nov.,Limnogonus cereiventris (Signoret,1862), andMicracanthia ornatula. (Orig.P.Kment:Figs 49–52;J.Hájek:Fig.53).