Metrocoris astictus Chen & Bu, 2016, sp. nov.
Creators: name: Chen, Zhen Ye Ping-Ping
name: Bu, Wen-Jun
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Gerridae
Metrocoris
Metrocoris astictus

description: Metrocoris astictus sp. nov.
(Figs. 17, 25, 30, 35, 40, 45, 50, 55, 63, 68, 72–74, 84)
Material examined. Holotype: apterous male, CHINA, Sichuan Prov., Luzhou city, Xuyong county, Huagaoxi Nature Reserve (28°09'N, 105°28'E), 15 August 2013, 817 m, leg. Zhen Ye (NKUM). Paratypes: 1 apterous male and 1 apterous female (NCTN), 1 apterous male and 1 apterous female (NKUM), same data as holotype.
Diagnosis. The relatively small body size (male body length 5.85–6.05; female body length 5.05–5.20) (Figs. 17, 25, 30); lateral pronotal stripe of pronotum nearly united to the inner margin of the eyes (Fig. 25); the relatively slender male fore femur (Fig. 40) only with a subapical indentation and a small single apical tooth (Fig. 40); the unmodified inner surface of fore tibiae (Fig. 40); the male proctiger elongate and laterally without a pair of blackish dots (Fig. 55); the typically falciform shape of paramere (Fig. 63); and the female abdominal sternum VII laterally constricted, with the apical half forming a half-round lobe, and the caudal margin without median notch (Fig. 35), are the diagnostic features of M. astictus sp. nov..
Description. Apterous male (Figs. 17, 25). Body length 5.85–6.05, body width (across acetabula) 2.60–2.65.
Colour: dorsum yellow with prominent black stripes; interocular dark mark usually arrowhead shaped, bifid posteriorly, along inner margin of eyes with narrowly indistinct dark line; first antennal segment yellowish brown, remaining segments usually blackish; rostrum yellowish with black apex; pronotum with T-shaped black stripe, lateral pronotal stripe very broad, nearly united to inner margin of eyes; mesonotum with median slender longitudinal stripe, sublateral stripes broader than lateral stripes, nearly equal in width to transverse bands; longitudinal dark stripe of mesopleuron slender, running at least 1/2 of its length, close to anterior margin but far from short acetabular mark; anterior transverse stripe of metanotum laterally confluent with posterior stripe of metanotum; fore femora with apical dark ring and four longitudinal marks, ventral mark connected with ring, remaining marks not confluent, inner mark pale and bright, external mark broad and blackish brown; middle and hind femora yellowish, tibiae and tarsi black; abdomen mainly blackish dorsally, abdominal tergites II–V blackish, abdominal tergites VI–VII blackish anteriorly and yellowish posteriorly; abdominal segment VIII with a large rectangular blackish mark in dorsal view, posteriorly with moderately bifid-shaped. Genital segments yellowish. Structural characters: head length 0.58–0.62, head width 1.60–1.64, minimum interocular width 0.69–0.73; antenna about 0.92 times as long as body, lengths of antennal segments I–IV: 2.45, 1.29, 1.10, 0.64; pronotum slightly narrower than head, pronotum length 0.70–0.74, pronotum width 1.68–1.72; fore femora slightly incrassate, ratio length/width 5.7, inner side not modified, with a subapical indentation, and a small single apical tooth (Fig. 40); inner surface of fore tibiae not modified (Fig. 40); lengths of leg segments (femur, tibia and tarsus): fore leg: 2.88, 2.15 and 0.90 (0.10+0.80), middle leg: 6.70, 5.21 and 2.44 (2.11+0.33), hind leg: 6.45, 4.55 and 0.60 (0.32+0.28); dorsum of abdomen clothed with short shiny golden hairs, venter of abdomen densely clothed with pale yellow hairs. Male terminalia: abdominal segment VIII more or less rectangular, length 1.34, width 0.88, about 1.52 times as long as wide, posterior margin with dense brown erect hairs (Fig. 45); pygophore subovate (Fig. 50), proctiger elongate and laterally without a pair of blackish dots (Fig. 55); paramere relatively stout and moderately curved upwards, extending beyond genital segments, blade of paramere laterally with small protuberance, apex blunt (Figs. 63, 74). Endosoma (Figs. 68, 72, 73): dorsal sclerite long and recurved proximally, accessory lateral sclerites slender and straight, ventral sclerites present and long.
Apterous female (Fig. 30). Body length 5.05–5.20, body width (across acetabula) 2.93–3.05. Colour similar to apterous male. Structural characters: head length 0.63–0.65, head width 1.47–1.51, minimum interocular width 0.54–0.56; antenna about 0.82 times as long as body, lengths of antennal segments I–IV: 1.77, 0.85, 0.91, 0.68; pronotum slightly narrower than head, pronotum length 0.49–0.51, pronotum width 1.40–1.43; fore femora slender without teeth, ratio length/width 6.2, inner surface of fore tibiae not modified; lengths of leg segments (femur, tibia and tarsus): fore leg: 2.21, 1.80 and 0.78 (0.10+0.68), middle leg: 6.02, 4.41 and 2.71 (2.23+0.47), hind leg: 5.78, 3.78 and 0.72 (0.38+0.34). Female terminalia: abdominal sternum VII relatively large, about as long as length of preceding abdominal sterna together, laterally constricted, apical half forming a half-round lobe, caudal margin without median notch, not completely covering apex of abdomen in ventral view (Fig. 35).
Macropterous female and macropterous male. unknown.
Etymology. The specific epithet “ astictus ” (from Latin, meaning unspotted) refers to male proctiger lacking a pair of blackish dots laterally.
Distribution. China (Sichuan) (Fig. 84).
Comparative notes: Metrocoris astictus sp. nov. fits the diagnostic characters of the M. lituratus group as defined by Chen & Nieser (1993). The general appearance of the paramere in this new species is slightly similar to that of another new species M. guizhouensis sp. nov. (see below), with both occurring in the southern region of the Sichuan Basin. However, the paramere blade of M. astictus sp. nov. is much more slender and slightly subapically curved (Figs. 63, 74), while the paramere blade of M. guizhouensis sp. nov. is relatively stout and its subapical part is not curving (Figs. 65, 80). In addition, the shorter body length (apterous male: 5.85–6.05; apterous female: 5.05– 5.20) (Figs. 17, 25, 30) and male proctiger lacking a pair of blackish dots laterally (Fig. 55) in M. astictus sp. nov., are also the important difference between these two closely related species.
description: Published as part of Chen, Zhen Ye Ping-Ping & Bu, Wen-Jun, 2016, Notes on the Metrocoris lituratus group (Heteroptera: Gerridae: Metrocoris) with descriptions of four new species in Sichuan Basin from China, pp. 359-374 in Zootaxa 4117 (3) on pages 368-369, DOI: 10.11646/zootaxa.4117.3.4, http://zenodo.org/record/269712