Amemboa (Amemboides) yunnana, Zettel & Yang & Tran, 2007

Zettel, Herbert, Yang, Chang Man & Tran, A. D., 2007, Two New Species Of Amemboa Subgenus Amemboides (Heteroptera: Gerridae) From China And Laos, Raffles Bulletin of Zoology 55 (2), pp. 223-229 : 224-225

Amemboa (Amemboides) yunnana , new species

( Figs. 1–5 )

Material examined. – Holotype (apterous male): China, Yunnan Prov., Mengla, mountain stream by waterfall, coll. L. Cheng, 18 May.2000, LC 001 ( ZRC).

Paratypes: China, Yunnan Prov.: 1 female (apterous) , 1 male, 3 females (macropterous), same label data as holotype ( CASB, ZRC, 1 macropterous female in NHMW) ; 1 female (apterous), Mengla, roadside stream, 5 km south from Mengla, road to Menglun, coll. L. Cheng, 18 May.2000. LC 002 ( ZRC) ; 1 male, 1 female (apterous), Menglun, pool at waterfall, coll. L. Cheng, 21 May.2000, LC 011 ( ZRC) ; 1 male (apterous), 1 female (macropterous), Mengyang, clear forest stream, Km 13, Menglun to Mengyang, coll. L. Cheng, 22 May.2000, LC 018 ( ZRC) ; 2 males, 4 females (apterous), 3 males (macropterous), Mengyang, clear forest stream, Km 20, Menglun to Mengyang , leg. L. Cheng, 22 May.2000, LC 019 ( ZRC, 1 female apterous, 1 male macropterous in NHMW) ; 2 males, 2 females (apterous), 2 males (macropterous), Mengla, (clear stream with) small waterfall, 28 km from Mengla, coll. L. Cheng, 24 May.2000, LC 031 ( ZRC, 1 macropterous male in NHMW) ; 3 males, 5 females (apterous), 1 female (macropterous), Xishuangbanna, Mengka, 55th stream, coll. C. M.Yang & P. Chew, 30 May.2002,YCM0303 ( CASB, ZRC, 1 apterous male, 1 apterous female in NHMW) ; 1 male, 1 female (apterous), Xishuangbanna, waterfalls nr. Mengyuan, coll. C. M. Yang & P. Chew, 1 Jun.2002, YCM0309 ( ZRC) ; 4 males, 5 females (apterous), 1 male, 3 females (macropterous), Menglun, Yulingku nature reserve , clear flowing creek, coll. L. Cheng, 21 May.2000, LC010 ( ZRC, apterous 2 males, 1 female, and 1 macropterous female in ZMUC) ; 2 females (apterous), 1 female (macropterous), Xishuangbanna, Mengka, small stream off Nanla River , coll. C. M. Yang, 2 Jun.2002, YCM0313 ( ZRC) ; 1 male, 2 females (apterous), 1 female (macropterous), Xishuangbanna, upstream of Nanla River , Wangtianshulin, coll. C. M. Yang, 2 Jun.2002, YCM314 ( ZRC) ; 6 males, 7 females (apterous), Xishuangbanna, Jinghong, Banna Nat. Park , rocky stream, coll. C. M.Yang & P. Chew, 7 Jun.2002,YCM0327 ( ZRC, 1 male, 1 female in NHMW) ; 3 males, 2 females (apterous), Man-Er stream, tributary of Mengkuan River , coll. H.M. Liu, 10 Jul.2001, ME2-001F, 003F, 007F, 009F ( ZRC) .

Description. – Apterous male: Size (measurements of holotype in square brackets): body length 4.1–4.6 mm [4.4 mm]; width of head across eyes 0.88–0.94 mm [0.90 mm]; maximum width across mesacetabula 1.30–1.53 mm [1.52

mm]; length of second antennomere [1.06 mm]; length of mesofemur [3.9 mm].

Colour: Yellowish-brown, dorsally and laterally with moderately contrasting brownish markings as typical for the genus; submedial brown stripes on mesonotum strongly expanded (at least in anterior half), narrowly connected with lateral stripes at about middle of length; metanotum darkest, blackish-brown, with pair of light brown areas; tergite 1 and connexival margins medially infuscated ( Fig. 1 ). Metasternum medially dark brown, almost black in some specimens; abdominal tergites more or less infuscated along midline. Silverish spots as typical for the subgenus, frosted areas laterally on metanotum and dots of silverish toment on mes- and metacetabula large and prominent, all strongly shiny.

Structural characteristics: Antennae longer than body; length of antennomeres 1–4: 1.0: 1.0: 1.3: 1.5. Rostral segment 3 with long suberect pilosity. Metanotum deeply sinuate at posterior margin. Relative lengths of leg segments (in percent of mesofemur): profemur: 41; protibia: 38; protarsus 3 + 7; mesofemur 100; mesotibia 63; mesotarsus 13 + 11; metafemur 86; metatibia 41; metatarsus 8 + 9; foreleg without modifications, profemur 5.1 as long as wide ( Fig. 2 ); first mesotarsomere 1.25 times as long as second. Pregenital abdominal venter ca. one tenth of body length; sternite 7 with relatively wide, but shallow, roundish emargination at hind margin, length along midline nearly as long as sternites 3–6 combined.

Male genital segments relatively large and wide; segment 8 ca. 1.7 times as long as wide. Pygophore small, posterior margin evenly convex, without tufts of hairs ( Fig. 3 ). Proctiger very elongate, almost parallel-sided, ca. 2.5 times as long as wide ( Fig. 4 ). Paramere very long, length ca. 0.6 mm, weakly curved at base, distally straight, slender, hardly narrowed towards narrowly rounded apex ( Fig. 5 ).

Macropterous male: Size: body length inclusive of wings 5.4–5.7 mm, exclusive of wings 4.8–5.1 mm; width of head at eyes 0.91–0.93 mm; maximum width at mesacetabula 1.48–1.55 mm.

Colour and structural characteristics similar to those of apterous male. Pronotal lobe medium to reddish-brown, with white hind margin; dorsal areas of meso- and metapleura vermilion; wings dark brown, veins light brown towards apex. Dorsal surface with numerous very short golden setae, more dense at base of pronotal lobe and on forewings.

Apterous female: Size: body length 4.3–5.2 mm; width of head across eyes 0.92–1.01 mm; maximum width across mesacetabula 1.72–2.01 mm.

Colour similar as in apterous male, except dark mark on metasternum usually less pronounced. Dorsal areas of meso- and metapleura vermilion in a few specimens.

Structural characteristics: Similar as in male. Rostrum with short pilosity. Concavity on hind margin of metanotum wider. Fore leg relatively simple, profemur less incrassate, first mesotarsomere ca. 1.4 times as long as second. Abdomen relatively short; sternite 7 slightly shorter than sternites 2–6 combined, ventrally with slightly longer pilosity, dorsocaudally rounded. Terminalia usually withdrawn into the half-pipe-shaped sternite 7, with tergite 8 and proctiger directed ventrad. Tergite 8 with sides turned up and set with long black pilosity (not forming distinct tufts).

Macropterous female: Size: body length inclusive of wings 5.5–6.2 mm, exclusive of wings 4.3–5.3 mm; width of head across eyes 0.88–0.99 mm; maximum width across mesacetabula 1.66–1.85 mm. Colour as in macropterous male.

Structural characteristics: Pronotum and wings as in macropterous male, most other characteristics as in apterous female. Sides of tergite 8 with pair of black hair tufts at approximately basal third of length.

Etymology. – This species is named after its occurence in Yunnan Province, China.

Remarks. – Amemboa yunnana resembles A. sexualis Polhemus & Andersen, 1984 , from Laos. The males of both species possess extremely long genital segments and long parameres. However, in A. yunnana the pygophore is apically rounded (versus emarginated in A. sexualis ) and the paramere is blade-shaped (versus falcate in A. sexualis ). Females of A. yunnana and A. sexualis differ in the pilosity of the metafemur and of the tergite 8: in A. yunnana the metafemur is without long pilosity and the tergite 8 with long black hairs, while in A. sexualis the metafemur bears long yellowish hairs, but the pilosity on tergite 8 is indistinct. When using the key provided by Polhemus & Andersen (1984), females key out with A. sexualis and A. velaris . Regarding the pilosity of the abdomen they more resemble A. velaris orientalis than A. velaris velaris (see Zettel & Chen, 1997). However this species differs from both subspecies in having broader shiny areas on the metanotum. All macropterous specimens of A. yunnana and a few apterous females have a distinct vermilion colouration on the dorsal part of the mesopleura and on the metacetabula. This characteristic has never been observed in A. velaris . The long pilosity on the third rostral segments of the males of A. yunnana may serve as a new distinguishing character for some species of Amemboides ; e.g., it is also present in A. perlata Polhemus & Andersen, 1984 .

Distribution. – Yunnan, China.

Habitats. – Specimens have been collected near shaded rocks either in clear, slow-flowing streams or by pools at waterfalls; station LC0018, in which both new species have been found, is a 200 m stretch of a fairly large (5 m wide) shady stream with steep banks providing a variety of microhabitats (Lanna Cheng, pers. comm.).

Figures

Figs. 1–5. Amemboa (Amemboides) yunnana, new species: 1, habitus of male; 2, male fore leg; 3, pygophore; 4, proctiger; 5, left paramere (two different views); Scales bars: 1–2 = 1 mm; 3–4 = 0.5 mm, 5 = 0.1 mm.