Metrocoris latus, Jehamalar & Dash, 2021

Jehamalar, E. Eyarin & Dash, Swetapadma, 2021, Three new species of Metrocoris Mayr, 1865 (Heteroptera: Gerridae) from India and establishment of species groups, Zootaxa 5082 (4), pp. 341-356 : 352-353

Metrocoris latus sp. nov.

( Figs. 4A–O )

Material examined. Holotype (apterous ♂): INDIA, MEGHALAYA, East Khasi Hills District, Khrang Village, Wahkwar River , 1326 m a.s.l., 25.32889° N, 91.79° E, 2.iii.2016, Coll. E.E. Jehamalar. Paratypes. 3 apt. ♂, 4 apt. ♀, 4 nymphs, same locality data as for holotype, Coll. E.E. Jehamalar. West Khasi Hills District, Porshieh Village, Rynniaw River , 926 m a.s.l., 25.65593° N, 91.06687° E, 16.iii.2018, 1 apt. ♂, Coll. E.E. Jehamalar.

Repository. The type specimens are deposited in the CEL, ZSI, New Alipore , Kolkata, West Bengal, India. Holotype Reg. No. 11563/H15 and paratypes Reg. No. 11564/H15–11565/H15.

Etymology. The word “latus” is a Latin adjective which means broad, referring to the very broad male paramere of this species.

Diagnosis. Metrocoris latus sp. nov. can be identified by the presence of a broad paramere ( Fig. 4N ) and the posteriorly concave, conical pygophore of the male ( Fig. 4M ); the hind trochanter of the female is posteriorly with a short sparse fringe of setae; the flexor region of the hind femur basally slightly expanded in the female; the mesopleural black stripe is not connected posteriorly with the mesoacetabular black mark and is anteriorly indistinctly connected with the transverse black mark and rarely not connected with the anterior black mark ( Fig. 4D ); the mesopleural yellowish-brown mark reaches up to the sublateral region of the mesosternum medially, the apex extended only posteriorly ( Fig. 4C ).

Description. Apterous male (holotype): ( Figs. 4A, D–G, J–O ). Body length 5.22 (4.12–5.22, n=5), body width at mesoacetabula 2.38 (1.87–2.46, n=5).

Colour. Dorsum of body black with yellowish-brown marks; broad black mark on head posterosublaterally connected with black mark near eyes ( Figs. 4A, D ); median black mark on head slightly bifid posteriorly; antenna and legs dark-brown to black; antennal tubercle black, base of first antennal segment yellowish-brown; rostrum dark-brown to black, except lateral region of first to third segments yellowish-brown; proacetabulum black; pronotum with T-shaped black mark, sublateral mark broad curved downwards, extended laterally and connected to lateral mark of mesonotum ( Fig. 4D ); small area near anterolateral region of pronotum below eye yellowish-brown, rarely visible; fore femur dorsally and ventrally with broad black stripe connected to apical black ring, extensor region yellowish-brown; mesonotal longitudinal medial and lateral dark marks connected to horizontal black marks anteriorly and posteriorly, sublateral black mark of mesonotum broader than adjacent yellowish-brown mark, not connected posteriorly to black mark between meso- and metanota ( Fig. 4A ); mesopleural black mark anteriorly connected with transverse black mark between propleura and mesopleura, but rarely not connected, posteriorly not connected with black mark of mesoacetabulum ( Fig. 4D ); mesopleural yellowish-brown mark reaches up to sublateral region of mesosternum medially, curl apically; yellowish-brown mark of metanotum linear than black mark between meso- and metanota; yellowish-brown mark on metacetabulum uninterrupted ( Fig. 4J ); area above base of metacetabular region with a small yellowish-brown mark; venter of body black, except mesosternal mark and apical region of abdomen, yellowish-brown; coxa and trochanter of all legs yellowish-brown, except mesolateral region with black mark; mid femur dorsally with long thin brown stripe; area surrounding omphalium reddish brown; dorsum of abdomen black, except posterolateral and apical region of connexivum, transverse mark on tergum VII and borders of tergum VIII yellowish-brown ( Fig. 4J ); venter of abdomen black, except posterior half of sterna VI and VII yellowish-brown; sternum VIII yellowish-brown, except anteromedially dark-brown to black.

Structural characteristics. Body clothed with small black adpressed irregularly arranged setae; venter of body covered with short silvery-white setae; eyes covering anterior 2/5 of propleura ( Fig. 4D ); antenna without characteristic setae; head laterally with four long black setae infront of eyes; eye width smaller than posterior eye width. Pleural region of prothorax posteriorly with few long black setae; fore femur slender, basally with three to four long setae, almost medially with shallow notch; mid femur slightly shorter than hind femur; anteromedian region of mesosternum densely clothed with long setae, prominent in lateral view; mesal region of meso- and metacetabula with thin stripe of short adpressed silvery-white setae. Abdominal terga I–VII and connexivum clothed with short silvery-white to golden setae; sternum VII longer than combined length of sterna V and VI; posterior margin of sternum VII concaved ( Fig. 4F ). Terminalia: Tergum VIII large, length and width subequal, posteriorly fringed with long brown setae, setal length reduced medially ( Figs. 4E, J ); basomedian region of sternum VIII depressed and constricted laterally, lateral margin of sternum VIII convex ( Fig. 4F ); sternum VIII slightly shorter than sternum VII; proctiger almost circular ( Fig. 4L ), not visible from above; pygophore conical, posteriorly concaved ( Fig. 4M ), pygophore mediolaterally shiny, lateral region with upwardly directed setae ( Figs. 4F, M ); paramere short, apically broad and blunt, sub-reniform, with short sparse setae ( Fig. 4N ), slightly visible from outside of genital segments ( Fig. 4E ). Endosoma in lateral aspect: proximal region of dorsal sclerite inwardly curved, with short reflex angled process; dorsal sclerite straight medially; accessory apical sclerite absent; accessory dorsal sclerite thin; basal sclerite not crossing lateral sclerite anteriorly; lateral sclerite proximally slightly bend upwards, with angulate tip; ventral sclerite very long ( Fig. 4O ).

Measurements. Head length 0.54, width 1.49; eye length 0.62, width 0.29, posterior eye width 0.40; synthlipsis 0.63; lengths of antennomeres I–IV 2.26, 0.88, 0.65, 0.71. Pronotal length 0.62, width 1.62; combined length of meso- and metanota 1.72; mesosternal length 2.01; metasternal length 0.14. Lengths of leg segments: foreleg: femur 2.32, tibia 1.96, tarsomeres I–II 0.14, 0.56; mid leg: femur 6.10, tibia 4.38, tarsomeres I–II 2.30, 0.38; hind leg: femur 6.33, tibia 2.97, tarsomeres I–II 0.33, 0.40; widths of fore, mid, hind femora 0.37, 0.26, 0.17. Length of abdominal tergum 2.30; length of abdominal sternum 1.72; lengths of abdominal sterna II–VIII 0.03, 0.07, 0.06, 0.08, 0.11, 0.31, 0.29; pygophore length 0.76; combined length of abdominal sterna V–VI 0.20; length of abdominal tergum VIII 0.91, width 0.92.

Apterous female (paratypes):( Figs.4B, C, H,I ). Body length 3.65 (3.65–4.50, n=4),body width at mesoacetabula 2.15 (2.15–2.60, n=4).

Colour. Similar to apterous male, except for the following characteristics: small area near anterolateral region of pronotum below eye yellowish-brown, visible; dorsum of abdomen black, except tergum VII with yellowish-brown transverse stripe ( Fig. 4I ); abdominal sterna IV–VII apically with yellowish-brown transverse mark, thickness of the mark gradually increased from sterna IV–VII; sternum VII with median longitudinal dark-brown to black hue ( Figs. 4C, H ).

Structural characteristics. Similar to apterous male, except for the following characteristics: genital segments completely concealed under sternum VII ( Figs. 4C, H ); sternum VII almost semicircular, slightly constricted laterally along midway; abdomen short, not reaching apex of hind coxa ( Figs. 4B, C, H, I ); hind coxa and trochanter not modified, except hind trochanter clothed with short black setae, pronounced apically.

Measurements. Head length 0.61, width 1.19; eye length 0.51, width 0.27, posterior eye width 0.30; synthlipsis 0.50; lengths of antennomeres I–IV 1.56, 0.68, 0.70, 0.61. Pronotal length 0.37, width 1.26; combined length of meso- and metanota 1.70; mesosternal length 1.87; metasternal length 0.09. Lengths of leg segments: foreleg: femur 1.72, tibia 1.40, tarsomeres I–II 0.09, 0.54; mid leg: femur 5.56, tibia 4.19, tarsomeres I–II 2.18, 0.38; hind leg: femur 5.69, tibia 2.78, tarsomeres I–II 0.35, 0.40; widths of fore, mid, hind femora 0.23, 0.25, 0.17. Length of abdominal tergum 1.05; length of abdominal sternum 0.88; lengths of abdominal sterna II–VII 0.09, 0.07, 0.07, 0.08, 0.13, 0.44; combined length of abdominal sterna II–VI 0.44; combined length of abdominal sterna V–VI 0.22; length of tergum VII 0.07.

Distribution. Known only from East and West Khasi Hills of Meghalaya, India.

Comparative notes. This species belongs to the M. latus group. Metrocoris latus sp. nov. shares the character of having the long ventral sclerite and predominantly black thoracic venter with M. issaci sp. nov. and M. josephi sp. nov. and M. nepalensis Distant, 1910 . However, the mesosternal yellow mark is absent in M. nepalensis and in M. issaci sp. nov. and M. josephi sp. nov. the apex of mesosternal yellowish-brown mark is extended both upwards and downwards and in M. latus sp. nov. it is only bent downwards and is not extended upwards ( Fig. 4C ). Metrocoris issaci sp. nov. and M. josephi sp. nov., with processes on the hind coxa and the hind trochanter of the female; however, it is absent in M. latus . The paramere is broad in M. latus and it is falciform in M. issaci sp. nov., M. josephi sp. nov. and M. nepalensis . The proctiger of the male is almost circular in M. latus ; however, it is subovate or elongate in the other compared species.

Figures

FIGURES 4. Metrocoris latus sp. nov., apterous form: A, male, dorsal view; B, female, dorsal view; C, female, ventral view; D, male, lateral view; E, male, abdominal tip, dorsal view; F, male, abdominal tip, ventral view; G, male, abdomen, lateral view; H, female, abdomen, ventral view; I, female, abdomen, dorsal view; J, male, abdomen, dorsal view; K, male, genital capsule, lateral view; L, male, proctiger, dorsal view; M, male, pygophore, dorsal view; N, male, paramere, lateral view; O, male, endosoma, lateral view.