Metrocoris falciformis, Chen, Zhen Ye Ping-Ping & Bu, Wen-Jun, 2016

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, Zootaxa 4117 (3), pp. 359-374 : 369-370

publication ID

https://doi.org/ 10.11646/zootaxa.4117.3.4

publication LSID

lsid:zoobank.org:pub:441C768B-FE38-47D6-819F-BE19CC167DB7

DOI

https://doi.org/10.5281/zenodo.6063138

persistent identifier

https://treatment.plazi.org/id/43435E3D-7210-E27E-FF40-4760FBB5FF0F

treatment provided by

Plazi

scientific name

Metrocoris falciformis
status

sp. nov.

Metrocoris falciformis View in CoL sp. nov.

( Figs. 18 View FIGURES 13 – 20 , 26 View FIGURES 21 – 28 , 31 View FIGURES 29 – 33 , 36, 41, 46, 51, 56, 64, 69, 75–77, 84)

Material examined. Holotype: apterous male, CHINA, Sichuan Prov., Bazhong city, Pingchang county, Zhenlong mountain Forest Park (31°48'N, 107°31'E), 24 July 2015, 1120 m, leg. Zhen Ye ( NKUM). Paratypes: 1 apterous male and 1 apterous female ( NCTN), 2 apterous males and 2 apterous females ( NKUM), same data as holotype.

Diagnosis. The relatively large body size (male body length 6.81–6.88) ( Figs. 18 View FIGURES 13 – 20 , 26 View FIGURES 21 – 28 ); longitudinal dark stripe on the mesopleuron running at least 2/3 of its length, and very close to anterior margin; fore femora bearing only with a subapical indentation and a small single apical tooth ( Fig. 41 View FIGURES 39 – 43 ); the unmodified inner surface of the fore tibiae ( Fig. 41 View FIGURES 39 – 43 ); the male proctiger with a pair of blackish dots laterally ( Fig. 56 View FIGURES 44 – 58 ); the typically falciform shape of the paramere ( Figs. 64 View FIGURES 59 – 66 , 77 View FIGURES 72 – 83 ); the laterally constricted female abdominal sternite VII, with the apical half forming a halfround lobe, and the caudal margin without median notch (Fig. 36), are the diagnostic features of M. falciformis sp. nov..

Description. Apterous male ( Figs. 18 View FIGURES 13 – 20 , 26 View FIGURES 21 – 28 ). Body length 6.81–6.88, body width (across acetabula) 3.01–3.09. Colour: dorsum yellow with prominent black stripes; interocular dark mark usually arrowhead-shaped, bifid posteriorly, with narrow dark line along inner margin of eyes; 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; mesonotum with slender longitudinal median stripe, sublateral stripes broader than lateral stripes, nearly equal in width to transverse bands; longitudinal dark stripe of mesopleuron slender, running at least 2/3 of its length, very 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 sub-rectangular blackish mark in dorsal view. Genital segments yellowish. Structural characters: head length 0.68–0.71, head width 1.66–1.70, minimum interocular width 0.63–0.66; antenna about 0.83 times as long as body, lengths of antennal segments I–IV: 2.65, 1.31, 1.10, 0.62; pronotum slightly narrower than head, pronotum length 0.75–0.78, pronotum width 1.89–1.92; fore femora moderately incrassate ( Fig. 41 View FIGURES 39 – 43 ), ratio length/width 4.9, inner side not modified, with a subapical indentation, and a small single apical tooth ( Fig. 41 View FIGURES 39 – 43 ); inner surface of fore tibiae not modified ( Fig. 41 View FIGURES 39 – 43 ); lengths of leg segments (femur, tibia and tarsus): fore leg: 3.17, 2.70 and 1.09 (0.09+1.00), middle leg: 8.01, 6.08 and 2.79 (2.42+0.37), hind leg: 7.71, 5.36 and 0.80 (0.44+0.36); dorsum of abdomen clothed with short shiny golden hair, venter of abdomen densely clothed with pale yellow hairs. Male terminalia: abdominal segment VIII more or less rectangular, length 1.58, width 1.02, about 1.55 times as long as wide, posterior margin with dense brown erect hairs ( Fig. 46 View FIGURES 44 – 58 ); pygophore subovate ( Fig. 51 View FIGURES 44 – 58 ), proctiger laterally with a pair of blackish dots ( Fig. 56 View FIGURES 44 – 58 ); paramere relatively slender and falciformly curved upwards, extending beyond genital segments, lateral part with distinctly angular projection, apex narrowed and blunt ( Figs. 64 View FIGURES 59 – 66 , 77 View FIGURES 72 – 83 ). Endosoma ( Figs. 69 View FIGURES 67 – 71 , 75, 76 View FIGURES 72 – 83 ): dorsal sclerite long and recurved proximally, accessory lateral sclerites straight, ventral sclerites present and long.

Apterous female ( Fig. 31 View FIGURES 29 – 33 ). Body length 6.26–6.31, body width (across acetabula) 3.39–3.43. Colour similar to apterous male. Structural characters: head length 0.71–0.73, head width 1.60–1.63, minimum interocular width 0.59–0.63; antenna about 0.74 times as long as body, lengths of antennal segments I–IV: 2.12, 1.04, 1.15, 0.73; pronotum slightly narrower than head, pronotum length 0.49–0.51, pronotum width 1.80–1.83; fore femora slender without teeth, ratio length/width 5.2, inner surface of fore tibiae not modified; lengths of leg segments (femur, tibia and tarsus): fore leg: 2.60, 2.34 and 1.01 (0.10+0.91), middle leg: 7.02, 5.32 and 2.86 (2.48+0.38), hind leg: 6.86, 4.78 and 0.98 (0.51+0.47). Female terminalia: abdominal sternum VII 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. 36).

Macropterous female and macropterous male. unknown.

Etymology. The specific epithet “ falciformis ” (from Latin, meaning acinaciform) refers to blade of paramere curved upwards and acinaciform-shaped.

Distribution. China (Sichuan) ( Fig. 84 View FIGURE 84 ).

Comparative notes: M. falciformis sp. nov. fits the diagnostic characters of the M. lituratus group as defined by Chen & Nieser (1993). The general appearance of this new species is similar to M. sichuanensis Chen & Nieser, 1993 . However, the paramere blade of M. falciformis sp. nov. is falciform-shaped, with the lateral part bearing a distinctly angular projection, and its blade apex narrowed ( Figs. 64 View FIGURES 59 – 66 , 77 View FIGURES 72 – 83 ), while in M. sichuanensis the paramere blade is relatively slender and straight, without an angular projection laterally, and the blade apex is slightly extended ( Figs. 5 View FIGURES 1 – 5 , 10 View FIGURES 6 – 12 , 59–62 View FIGURES 59 – 66 ). In addition, the larger male abdominal segment VIII ( Fig. 46 View FIGURES 44 – 58 ) and pygophore ( Fig. 51 View FIGURES 44 – 58 ) and the caudal margin of female abdominal sternum VII without median notch in M. falciformis sp. nov. (Fig. 36), represent further important differences between these two closely related species.

NKUM

Nankai University

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hemiptera

Family

Gerridae

Genus

Metrocoris

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