Aphelocheirus (s.str.) gularis HORVÁTH, 1918

Zettel, H. & Tran, A. D., 2009, Notes On The Aphelocheiridae (Heteroptera) From Indochina, With Redescriptions Of Aphelocheirus Inops And A. Gularis And The Description Of A New Species From Vietnam, Acta Zoologica Academiae Scientiarum Hungaricae 55 (3), pp. 211-226 : 217-219

Aphelocheirus (s.str.) gularis HORVÁTH, 1918

( Figs 2 , 4, 7, 8, 12, 20–25)

Aphelochirus gularis HORVÁTH, 1918: 141 .

Aphelocheirus (Aphelocheirus) gularis (HORVÁTH) : POLHEMUS & POLHEMUS 1989: 222–224.

Material examined. Holotype (macropterous male): “ Annam \ Laos ”, “gularis H.\ det.Horváth”, “ Aphelochirus \ gularis Horv. ”, “Coll. Mus.\ Nat.Hung.”, “TYPUS”, “Loan\ from\ Budapest”, “ HOLOTYPUS \ Aphelochirus \ gularis Horváth, 1918 \. labelled Zettel & Tran 2008” ( HNHM). A dditional material: 1 female (brachypterous; paralectotype of A. inops ) “ Annam \ Laos ”, “inops H.\ det.Horváth”, “TYPUS”, “ PARALECTOTYPUS \ Aphelochirus \ inops Horváth, 1918 \ labelled Zettel & Tran 2008”, “ Aphelocheirus \ gularis Horváth, 1918 \ det. Zettel & Tran 2008” ( MTMB); 1 male, 4 females (brachypterous), Vietnam: Cao Bang Prov., Ha Quang, Soc Ha, 16.XII.2000, Coll. V.V. Nguyen & X.N. Ngo, # VNCB0001 ( ZRCS, NHMW); 8 males, 4 females (brachypterous) Vietnam: Ha Giang Prov., Vi Xuyen, Viet Lam stream, 11.XII.2000, Coll. V.V. Nguyen & X.N. Ngo, # VNHG0001 ( ZMHU, ZRCS, NHMW); 1 male, 1 female (brachypterous) Vietnam: Quang Binh Prov., Phong Nha, Vuc Tro stream, 14.VII.2004, 34 m a.s.l., pH 8.3, 17°38.188’N 106°12.810’E, Coll. D.C.J. Yeo, A.D. Tran & al. DY0404 ( ZMHU).

Description of macropterous male (holotype). Size. Body length 6.8 mm. Body width 4.5 mm. Pronotum width 3.2 mm.

Note that macropterous specimens of Aphelocheirus usually differ from brachypterous individuals by the following characteristics: colour slightly darker; sculpturing of head, pronotum and mesoscutellum slightly coarser; eyes slightly larger; pronotum of very different shape; mesoscutellum strongly enlarged; forewings reaching approximately to abdominal tip.

Colour. Dorsal colour pattern as in Figure 2 . Ventral side, including appendages, yellowish, partly brownish infuscated.

Head ( Fig. 2 ) moderately short, length 0.9 times head width; irregularly punctured, large and small punctures mixed; anterior section of head short, 0.5 times eye length. Pronotum ( Fig. 2 ) slightly convex, with sinuate hind margin; median length of pronotum 0.75 times median head length; maximum width near posterior corners 3.4 times median length; width at anterior corners 0.45 times maximum width. Propleuron with medial process as in brachypterous morph (comp. Fig. 4). Mesosternum (Fig. 7) with similar median carina as in brachypterous morph, but less highly raised above the more swollen mesosoma. Embolar margin of hemielytron strongly expanded laterally, forming a sharp, wing-shaped process ( Fig. 2 ). Abdomen including genitalia as in brachypterous morph.

Description of brachypterous male. Size. Body length 6.7–7.0 mm. Body width 4.7–5.0 mm. Pronotum width 3.6–3.8 mm.

Colour. Head yellow, anterior margin usually more or less infuscated. Pronotum, mesoscutellum, hemielytra, and tergites either uniformly dark brown or with vague pattern of yellowish brown marks: paired dots near middle of pronotal disk, sides of mesoscutellum, transverse fasciae on posterior half of hemielytra, and 1–2 paired dots on tergites. Ventral side including appendages yellowish, few parts brownish infuscated.

Head short, length 0.95 times head width; dorsal surface with densely set, mixed large and small punctures, posteriorly confluent, anteriorly with shiny interspaces. Anterior section of head (anterior of anterior eye margin) short, 0.5 times eye length (eye length measured parallel with median line of head). Rostrum short, 1.4 times as long as profemur, hardly surpassing mesosternum.

Thorax: Pronotum with distinctly convex disk, coarsely granulate, except on two small areas close to middle rugose with shiny interspaces. Median pronotum length 0.65 times median head length. Maximum width at posterolateral corners, 3.7 times median length. Lateral margins of pronotum strongly convex and convergent anteriorly; width at anterolateral corners 0.45 times maximum width. Prosternum anteromedially with small lobe. Propleuron (Fig. 4) medially with narrow, triangular process, demarcated by almost rectangular incision; apex acute. Mesosternum (Fig. 8) with high, anteriorly rounded median hump. Mesoscutellum coarsely granulate; anterior width 2.8 times median length, its centre slightly convex.

Hemielytra coarsely granulate, posteriorly not reaching posterior margin of tergite 2, medially without or with small gap measuring up to one eighth of hemielytron width. Each hemielytron much wider than long (ca. 1.6 times), laterally with short triangular embolar process (process width 0.07 times total hemielytron width).

Legs relatively short and stout, femora scarcely exceeding lateral margin of body. Profemur 2.8 times as long as wide, slightly shorter than both, meso- and metafemur; those without modifications.

Abdomen. Tergites 2–7 with acute posterolateral corners, but corners of tergites 2 and 3 almost rectangular, those on tergites 4 and 5 with triangular teeth. Sternites asymmetrical, sternite 3 medioposteriorly with small tubercle, sternite 4 with 2–4, sternite 5 with 3–5, sternite 6 with 0–4 peg-like setae.

Genitalia. Pygophore with both parandria of subequal length and similar shape (Fig. 20), long and almost steadily narrowed towards apex, but left parandrium much broader and partly covering right in caudal aspect. Main body of aedeagus (Fig. 20) with sharp apex curved to right. Left paramere (Figs 21, 22) stout, subparallel except slightly broadened in apical part, with strong bend in basal third, with only short setiferation. Right paramere (Figs 23–25) strongly curved at base, distal part slender, almost straight, and steadily narrowed towards acute apex, only with short setiferation.

Description of brachypterous female. Size (smallest specimen is paralectotype of A. inops ). Body length 6.6–7.5 mm. Body width 4.6–5.2 mm. Pronotum width 3.5–3.8 mm. Similar to brachypterous male. Abdomen symmetrical, sternite 4 with 2–4, sternite 5 with 3–4, sternite 6 with 3–5 peg-like setae (in some specimens all setae broken off). Subgenital plate (Fig. 12) very broad, subtriangular, with broadly rounded apex, but usually with distinct minute, triangular or lobe-shaped, medial tip; sides convex, with narrow tufts of long, curved setae at about mid-length; subapical, medial tuft of setae directed straight caudad.

Discussion. Aphelocheirus gularis , A. dudgeoni POLHEMUS et POLHEMUS, 1989 from Hong Kong and Guangxi, A. hainanensis ZETTEL, 1998 and A. ellipsoideus LIU et DING, 2005 both from Hainan Island form a complex of similar and probably closely related species. Aphelocheirus dudgeoni and A. ellipsoideus differ from the other two species in separated forewings of the brachypterous morph (in A. ellipsoideus more than in A. dudgeoni ), the shape of both parameres of the male (see ZETTEL 1998: figs 54–57, LIU & DING 2005: figs 2–5), and a slightly incised apical margin of the female’s subgenital plate (in A. dudgeoni ; female of A. ellipsoideus unknown). Whereas specimens of A. dudgeoni from Hong Kong are nearly uniformly yellowish brown, specimens from Guangxi have a discrete pattern of brownish dots on the dorsal surface ( ZETTEL 1998). Aphelocheirus gularis and A. hainanensis are most similar. ZETTEL (1998) compared A. hainanensis with the description of A. gularis by POLHEMUS and POLHEMUS (1989), because the type was not available for study at that time. However, the differences stated by ZETTEL (1998) must be corrected or re-evaluated after examination of the type and the non-type material: The colour of the head depends on the wing morph (yellow in brachypterous specimens, brown in macropterous specimens of A. gularis ), but is not consistently different in the two species. Variations of the medial structures of the mesosternum also are dependent on the wing morph. The labrum is punctate in both species, not smooth and shiny as described by POLHEMUS and POLHEMUS (1989) for the holotype of A. gularis . The ratio of head width and head length seems to be slightly larger in A. hainanensis than in A. gularis ; however, measurements of the median head length can vary due to the degree of deflexion of the head. Thus, in general, small differences of reported ratios are inappropriate for species separation. The concavity of the apical margin of the left paramere ( ZETTEL 1998: p. 88 referred erroneously to the right paramere) of A. gularis is less concave (compare Figs 21, 22) than in the illustration by POLHEMUS and POLHEMUS (1989: fig. 89) and more similar (but not identical) with the same structure in A. hainanensis . In addition to this small difference in the left paramere, the colour pattern of the brachypterous morph of the two populations is different: A. hainanensis has numerous bright yellowish to orange marks on pronotum, hemielytra, and tergites, whereas A. gularis is usually uniformly dark brown or has, rarely, indistinct orange-brown spots. The differences between A. gularis and A. hainanensis are so small that the two taxa might actually represent only subspecies of a single species, but at present this cannot be confirmed by morphology. The situation is further complicated by the existence of a female described below.

Distribution. For explanation of the type locality see the Distribution section for A. inops . Exact locality data (all based on males) are available from the provinces Cao Bang, Ha Giang, and Quang Binh in Vietnam.

Figures

Figs 1–2. Habitus, dorsal aspect: 1 = brachypterous male of A. inops (lectotype by present designation; body length 6.9 mm), 2 = macropterous male of A. gularis (holotype; body length 6.8 mm). La-