Hebrus fulvinervis Horvath 1929

Hebrus fulvinervis Horváth, 1929

(Figs. 40–43, 46–65)

Hebrus ruficeps (misidentification): Lindberg (1922): 16 (faunistics).

Hebrus fulvinervis Horváth, 1929: 313 (original description, comparison with H. ruficeps). Syntypes: 7 specimens, Romania: Cruce (1 spec.), Sibiu (2 spec.), Râu de Mori (1 spec.); Bosnia and Herzegovina: Jablanica (1 spec.), Sarajevo (2 spec.) (HNHM).

Neogaeus fulvinervis: Jordan (1954): 603 –604 (comparison with remaining species of Europe and Near East); Wagner (1957): 202 (comparison with H. franzi).

Hebrus fulvinervis: Stichel (1955): 150 –151 (key, diagnosis), Stichel (1956): 162 (catalogue), Benedek (1969): 83 (key), Benedek (1970): 43 –44 (faunistics); Andersen (1995): 80 (catalogue).

Type material examined. Syntypes: 1 ♀ (macropterous), ‘Malomviz / Pável [p, white label] // fulvinervis [hw, underlined with red] / det. Horváth [p, white label] // TYPUS [p, red label]’ (HNHM); 1 Ƌ 1 ♀ (brachypterous), ‘Nagyszeben / Coll. Fuss [p, white label] // pusillus [hw] Coll. Fuss [p, white label] // fulvinervis [hw, underlined with red] / det. Horváth [p, white label] // Ƌ or ♀ [hw; respectively] / TYPUS [p, red label]’ (HNHM).

Additional material examined. BULGARIA: Blagoevgrad Province: Gara Sandanski, Struma, 20.vii.1956, 3 Ƌ 3 ♀, L. Hoberlandt lgt., P. Kment det. (NMPC); Gotse Delchev (→ Ognianovo), Mesta river banks, 500 m a.s.l., Locality No. 13B/72, 16.viii.1972, 1 Ƌ (brachypterous), A. Merta lgt. (MMBC).

Redescription. Macropterous and brachypterous form. Colouration (Figs. 40–43). Head yellowish to reddish brown, in some specimens somewhat darker anteriorly, sometimes narrowly infuscate around ocelli. Eyes red to dark brown. Antennal segments brown, basal two thirds of segment I and basal third of segment II paler, yellowish brown. Bucculae and labium yellowish brown. Pronotum and mesoscutellum yellowish to reddish brown, in some specimens pronotum anterolaterally dark brown; metanotal elevation (‘scutellum’) darker than pronotum, brown to dark brown. Propleura and meso- and metacoxal cavities yellowish to reddish brown, remaining portions of meso- and metathorax ventrally brown. Legs yellowish to pale brown. Clavus anteriorly milky white, in its posterior one to two thirds gradually becoming brown. Veins of corium yellowish to reddish brown, concolorous with disc of pronotum, only anteriorly infuscated with dark brown; corium between veins white. Membrane of brachypterous form completely brown (Fig. 41), in macropterous form brown with conspicuous oval whitish central spot, and two indistinct paler spots anterolaterally (Figs. 40, 42–43). Abdomen dark brown, pygophore slightly paler.

Vestiture. Pubescence on head, pronotum, sides of thorax, mesoscutellum and metanotal elevation (‘scutellum’) very short, in optical microscope indistinct (see Figs. 46–53). Clavus completely bare (Figs. 50–53). Vein of corium with distinct, short and fine pale setae (Figs. 46, 50). Thorax and abdomen ventrally with dense silver pubescence. Antennae and legs with long pale hairs (Figs. 48–49, 55–56).

Structure. Body elongate (Figs. 40–43, 46–47), about 2.3–2.6× longer than wide across humeral angles. Vertex with median sulcus not visible (Figs. 48–49). Bucculae low, ventrally straight, posteriorly conically produced (Fig. 55). Labium reaching anterior margin of metacoxae. Antennal segment I stoutest, cylindrical, slightly curved (Figs. 42–43, 48–49, 54–55); segment II clavate (Figs. 42–43, 54); segments III and IVa terete (Figs. 4 2–43, 54); segment IVb narrowly fusiform (Figs. 42–43, 54). Antennal segments from longest to shortest (Fig. 54): III> IVb ≥ I ≥ II ≥ IVa; segment I usually slightly longer than II (1.14×) and as long as compound eye (Fig. 55), rarely as long as II; segment IV fully divided into IVa and IVb (Figs. 54, 56). Pronotum (Figs. 46–47, 50–51) transverselly hexagonal, anterior collar narrow, middle transverse constriction deeper and humeral angles more arcuately produced in macropterous form (pronotum humeral width 0.69–0.79 mm; Figs. 46, 50) than in brachypterous form (pronotum humeral width 0.59–0.67; Figs. 47, 51). Metanotal elevation trapezoid; in macropterous form longer (2.8× wider than long), posteriorly with wide and deep U-shaped incision (Fig. 52), in brachypterous form shorter (3.1× wider than long), posteriorly widely truncate with only shallow U-shaped incision (Fig. 53); disc of metanotal elevation anteriorly depressed with more or less well developed median carina, posteriorly flat (Figs. 52–53), not turned upwards (Fig. 54). Metapleuron only slightly gibbose, metathorax therefore not wider than pronotum. Hemelytra of macropterous form reaching (Figs. 42–43, 46) or nearly reaching (Fig. 40) apex of abdomen. Hemelytra of brachypterous form reaching posterior margin of mediotergite IV (about midlength of abdomen), veins of corium reaching only midlength of mediotergite III (Figs. 41, 47). Metafemora and metatibiae of both sexes straight, without long hairs (Figs. 42–43, 46, 54). Mediotergites I and II with two thin, submedian, posteriad slightly diverging longitudinal keels. Male genitalia: Pygophore obovate in dorsal view (Figs. 57–59); proctiger short, posteriorly oval (Fig. 62), only slightly protruding from pygophore outline posteriorly (Figs. 57–59); paramere hook-shaped (Figs. 60–61); aedeagus as in Figs. 63–64.

Measurements (mm). Brachypterous form. Male / female (n = 2 / 1). Body length: 1.51–1.74 / 1.66. Pronotum: anterior width: 0.34–0.36 / 0.36, humeral width: 0.59–0.67 / 0.65. Lengths of antennal segments: I: 0.14 / 0.14, II: 0.12–0.14 / 0.14, III:–/ 0.18, IVa:–/ 0.12, IVb:–/ 0.14. Length of metafemur: 0.44 / 0.5, metatibia: 0.52 / 0.55, metatarsus: 0.18 / –.

Macropterous form. Male / female (n = 3 / 4; median (minimum–maximum)). Body length: 1.66 (1.60–1.68) / 1.80 (1.78–1.82). Pronotum: anterior width: 0.36 (0.34–0.36) / 0.38 (0.36–0.38), humeral width: 0.71 (0.69–0.71) / 0.77 (0.75–0.79). Lengths of antennal segments: I: 0.14 (0.14–0.16) / 0.14 (0.14–0.16), II: 0.12 (0.12–0.14) / 0.13 (0.12–0.14), III: 0.20 (0.20–0.20) / 0.20 (0.20–0.22), IVa: 0.12 (0.12–0.12) / 0.12 (0.10–0.14), IVb: 0.16 (0.16– 0.16) / 0.16 (0.16–0.16). Length of metafemur: 0.50 (0.46–0.50) / 0.48 (0.48–0.50), metatibia: 0.55 (0.53–0.57) / 0.55 (0.55–0.59), metatarsus: 0.16 (0.16–0.16) / 0.16 (0.16–0.20).

Systematic placement and differential diagnosis. The complete subdivision of antennal segment IV into two (IVa and IVb—see Fig. 56) as well as other characters relating it to H. ruficeps, justify the transfer of Hebrus fulvinervis to the subgenus Hebrusella as defined by Poisson (1944).

Hebrus fulvinervis seems closely related to Euro-Siberian H. ruficeps, both sharing the dimorphism of hemelytra development and antennal segment I as long as or only slightly longer than segment II (Jordan 1954, Stichel 1955, Benedek 1969). All African species of the subgenus Hebrusella are known only in the macropterous form.

However, H. fulvinervis differs from H. ruficeps by being slightly larger (macropterous form 1.60–1.82 mm, brachypterous form 1.51–1.74 mm) (in H. ruficeps 1.20–1.70 mm) (e.g. Benedek 1969, Savage 1989); macropterous specimens are more frequent than brachypterous specimens (in H. ruficeps the macropterous form is rare) (Benedek 1969), the hemelytra of macropterous form usually reaches the end of the abdomen (Figs. 42–43) (in H. ruficeps the hemelytra of the macropterous form reaches only mediotergite VII) (Benedek 1969); the shortwinged form is brachypterous with the hemelytra reaching the posterior margin of mediotergite IV (Fig. 41) (micropterous in H. ruficeps, with the hemelytra reaching only to the anterior margin of mediotergite II—Fig. 44) (Horváth 1929, Benedek 1969); the veins of the corium are yellowish brown (Figs. 42–43) (in H. ruficeps the veins of the corium are dark reddish brown or dark brown—Fig. 45) (Stichel 1955); and antennal segment IVb is only slightly (1.17–1.33) longer than IVa (in H. ruficeps antennal segment IVb is more than twice longer than IVa) (Jordan 1954).

Habitat. According to the locality database of the MMBC, the specimen from Gotse Delchev was collected on the left bank of Mesta River, most probably in a muddy habitat surrounded by Salix spp. and Alnus glutinosa (sunny weather, temperature 25–38°C, 10:30–15:00) (I. Malenovský, pers. comm.).

Distribution (Fig. 65). Europe: Bosnia Herzegovina: Ilidža (= Ilidze) [43°49′51″N 18°17′56″E] (Lindberg 1922, as H. ruficeps; Benedek 1970), Sarajevo [43°51′27″N 18°24′45″E], Jablanica (= Jablanitza) [43°39′27″N 17°45′38″E] (Horváth 1929); Bulgaria: Gotse Delchev [41°34′21″N 23°43′43″E], Sandanski [41°33′34″N 23°16′23″E] (this paper); Romania: Sibiu county: Sibiu (= Cibinium, Nagyszeben) [45°47′54″N 24°07′32″E], Hunedoara county: Râu de Mori (= Malomvíz) [45°29′48″N 22°51′15″E], Suceava county: Crucea (= Cruce) [47°21′03″N 25°36′29″E] (Horváth 1929). New species for Bulgaria.