Metrocoris shillongensis, Jehamalar, E. Eyarin & Chandra, Kailash, 2013

Jehamalar, E. Eyarin & Chandra, Kailash, 2013, Two new species of Metrocoris Mayr (Hemiptera: Heteroptera: Gerridae) from India, Zootaxa 3734 (1), pp. 63-71 : 66-71

Metrocoris shillongensis sp. nov.

( Figs. 2A–L )

Material examined. Holotype. ♂, (mac.): INDIA, Meghalaya, East Khasi Hills District, Shillong, Botanical Garden, 4885 ft [1488.94 m], N 25°34’33.19’’, E 91°53’12.76’’, 30.vii.1960, Coll. S.N. Prasad.

Paratypes. Same data as that of holotype 1 (mac.) ♀, 2 (apt.) ♀; INDIA, Meghalaya, Ri-Bhoi District, Barapani (near Khwan Village) between mile stone 57-58 on Guwahati-Shillong Road, (ca 8 miles away from Shillong) from a stream, 4229 ft [1288.99 m], N 25°37’19.49’’, E 91°52’54.23’’, 19.i.1961, 1 (apt.) ♂, 3 (apt.) ♀ Coll: J.K. Sen.

Diagnosis. Incrassated male fore femur with a small single tooth in the middle of indentation between two protuberances on the inner sub apex, inner margin of fore femur distinctly bisinuated ( Fig. 2E ); fore tibia of male inwardly curved; distinctive male paramere ( Figs. 2H ); distinctly shaped male proctiger ( Fig. 2J ); finger-shaped projection on postero-lateral margin of female sternum VII ( Fig. 2K ).

Description. Macropterous male (Holotype). ( Figs. 2E–J ) n=1, Body length 6.61, width (across mesoacetabula) 3.2.

Colour. Yellowish brown with prominent black stripe; interocular rectangular dark stripe anteriorly bifid, posteriorly connected to dark stripe of inner margin of eyes; antennal sockets, tylus and posterior part of rostrum, lateral region of fore coxa, anterior region of mesosternum near fore trochanter, along anterior portion of mesoacetabular suture piceous; antenna dark brown except at base of first segment yellow; legs dark brown, middle and hind femur with dark longitudinal stripe on lateral margin; external face of fore femur with large dark mark, connected to apical dark ring posteriorly, and anterior portion yellowish brown; body venter yellowish brown; antero-lateral margin of pronotum near to posterior margin of eye with yellow hue; anterior margin of pronotum with transverse piceous stripe, curving downwards laterally and reaches upto humeral angle, in dorsal aspect lateral stripe appearing interrupted above humeral angle; pronotal lobe with median longitudinal stripe and pair of broad lateral stripe confluent near apex, its free end running beyond humeral angle; longitudinal stripe of mesopleuron long, not connected with anterior margin and short mesoacetabular stripe; posterior part of pronotal lobe slightly ridged along median stripe; wings dark brown.

Structural characters. Head length 0.75, width 1.84, minimum interocular width 0.7; eye width 0.8, posterior eye width 0.55; antennal length I–IV 2.62, 1.33, 0.99, 0.71; rostral length III, IV 0.7, 0.31; pronotal lobe length 3.66, width 2.8. Legs measurements: Fore femur length 3.38, width 0.83; inner margin of fore trochanter, inner margin of basal margin of fore femur and posterior part of inner fore tibia fringed with numerous short hairs; fore tibial length 2.56; fore tarsus I 0.15; fore tarsus II 1.11; hind trochanter length 0.83, hind trochanter without conspicuous long brown hairs (other leg parts broken); posterior margin of abdominal segment eight without prominent fringe of long hairs ( Fig. 2I ), length of abdominal tergites VIII 0.66, width 1.06; paramere falciform with blunt tip ( Fig. 2H ); endosoma as in Fig. 2G ; length of basal part of hemelytra 3.77.

Apterous male (Paratypes). (n=1), Body length 5.66, width (across mesoacetabula) 2.57.

Colour. General colour as macropterous, some exceptions and the thoracic colour pattern of apterous form is given here: interocular dark mark posteriorly connected to longitudinal dark mark of pronotum and laterally to dark stripe of inner margin of eyes; anterior margin of pronotum near to posterior eye yellow, pronotum with T-shaped stripe, lateral pronotal stripe very broad, confluent to lateral stripe of mesonotum in lateral aspect; mesonotum with median longitudinal stripe, broad sublateral stripe not connected to transverse stripe of anterior region of metanotum, lateral pronotal stripe very broad, confluent to lateral stripe of metanotum; longitudinal stripe of mesopleuron long, running throughout its length, not interrupted adjacent to metathoracic spiracle; anterior transverse stripe of metanotum laterally confluent with posterior stripe of metanotum; yellow mark of metacetabulum not interrupted; external face of fore femur with large black mark, connected to apical dark ring posteriorly; abdominal tergum one with pair of yellow stripe, segments three to eight lower region yellow.

Structural characters. Head length 0.73, width 1.62, minimum interocular width 0.6; eye length 0.75, eye width 0.37, posterior eye width 0.42, eyes overlapping more than 1/3 of propleura; antennal length I-IV 2.02, 1.07, 0.77, 0.55; rostral length III, IV 0.62, 0.2; head with seven to nine long brown setae along inner margin of eyes.

Pronotal length 0.62, width 1.64; Legs measurements: fore femur length 2.7, width 0.65; fore tibial length 2.23; fore tarsus I 0.1; fore tarsus II 1.04; hind trochanter length 0.59; hind femur length 6.63, width 0.18; length of abdominal tergites VIII 0.77, width 1.1. Other characters similar to holotype.

Apterous female ( Figs. 2A, D, K, L ). The measurements are given as mean value of 5 female specimens followed by range in square brackets. Body length 5.09 [4.76–5.24], width (across mesoacetabula) 2.95 [2.83– 3.17]. Colour and structural characters similar to holotype and apterous male with the following exceptions:

Body length of females little smaller than males; fore femur linear; lower margin of fore trochanter with four long setae and lower margin of fore femur with nine long setae from base up to middle; seventh abdominal sternum of female longer than combined length of preceding abdominal segments, tergum II to VII yellowish brown on posterior region, yellowish brown hue on tergite seven in middle intruded anteriorly over the black mark ( Fig. 2A ); tergite VIII black; specimens collected in the year 1961 having a pair of reddish brown broad stripes on mesosternum of both males and females.

Structural characters. Head length 0.7, width 1.58, minimum interocular width 0.62; eye length 0.7, eye width 0.4, posterior eye width 0.45; antennal length I-IV 1.11, 0.8, 0.75, 0.55; rostral length III, IV 0.53, 0.22; pronotal length 0.49, width 1.6. Legs measurements: Fore femur length 2.21 [2.05–2.45], width 0.3 [0.27–0.36]; fore tibial length 1.8 [1.69–1.94]; fore tarsus I 0.12 [0.1–0.15]; fore tarsus II 0.82 [0.64–0.93]; mid femur length 5.99 [5.72–6.5], width 0.26 [0.21–0.3]; mid tibia 4.56 [4.01–5.12]; mid tarsus I 1.87 [0.74–2.54]; mid tarsus II 0.29 [0.27–0.3]; hind trochanter length 0.6 [0.53–0.64]; hind femur length 5.59 [5.32–6.09], width 0.22 [0.2– 0.25]; hind tibia 3.75 [3.35–4.36]; hind tarsus I 0.32 [0.25–0.41]; hind tarsus II 0.28 [0.2–0.38]; metasternal length 0.18 [0.16–0.23], combined length of abdominal sternites II–VI 0.61; sternite VI 0.17; sternite VII 0.8; sternite VIII 0.07.

Macropterous female ( Figs. 2B ) n=1

Body length 5.1, width (across mesoacetabula) 2.93.

Similar colour pattern as for holotype.

Structural characters. Head length 0.78, width 1.65, minimum interocular width 0.64; eye length 0.74; eye width 0.42, posterior eye width 0.45; antennal length I–IV 0.95, 0.89, 0.82, 0.55; rostral length III, IV 0.65, 0.21; pronotal lobe length 3.3, width 2.4. Legs measurements: Fore femur length 2.37, width 0.33; fore tibial length 1.97; fore tarsus I 0.18; fore tarsus II 0.92; mid femur length 6.29, width 0.29; mid tibia 4.77; mid tarsus I 2.22; mid tarsus II 0.29; hind trochanter length 0.55; hind femur length 6.02, width 0.25; hind tibia 4.38; hind tarsus I 0.37; hind tarsus II 0.34; metasternal length 0.18; combined length of abdominal sternites II–VI 0.59; sternite VI 0.18; sternite VII 0.82; sternite VIII 0.07; length of anterolateral margin of pronotum 1.08; length of posterolateral margin of pronotum 2.54; length of basal part of hemelytra 3.2.

Repository. The type specimens are deposited in the CEL, ZSI, Kolkata. Holotype Reg. No. 3038/H15, Paratypes Reg. No. 3039/H15 to 3040/H15.

Etymology. This species is named after the collection locality, Shillong, in northeast India.

Comparative notes. M. shillongensis sp. nov. is closely related to M. obscurus Chen & Nieser, 1993 . In M. obscurus the first antennal segment is subequal to the length of the remaining three segments together, but in the new species the first segment is distinctly less that the remaining three segments together. The fore femoral tooth is distal to the notch in M. obscurus but in M. shillongensis sp. nov. the tooth is on the middle of the inner subapical notch. In M. obscurus the interocular dark mark is bifid at both anterior and posterior ends, but in M. shillongensis sp. nov. only the anterior end is bifid. Tergite one has a pair of yellow marks in M. shillongensis sp. nov., but this mark is absent in M. obscurus . In M. obscurus the eye width is larger than the posterior eye width but in M. shillongensis sp. nov. the eye width is less than the posterior eye. The distal outer margin of the male paramere is protruded medially in M. obscurus , but in M. shillongensis sp. nov. the distal outer margin is simple and not protruded.

Acknowledgements

The authors are thankful to the Director, Dr. K. Venkataraman, Zoological Survey of India, Kolkata, for facilities and encouragement. The authors are thankful to MOEF, New Delhi, for funding the project on Great Nicobar Biosphere Reserve. We are grateful to Dr. C. Raghunathan, Officer-in-Charge, Andaman and Nicobar Regional Centre, ZSI, for support rendered for field trips. We are thankful to Dr. Herbert Zettel, International Research Institute of Entomology, Natural History Museum, Vienna, Austria; Dr. Nico Nieser, Tiel, The Netherlands; Dr. Dan A. Polhemus, Department of Natural Sciences, Bishop Museum, Honolulu, USA; Miss. Srimoyee Basu, Research Scholar, ZSI Kolkata, for providing some literature on the group. Our sincere thanks are due to Dr. John C. Morse, Emeritus Professor and Emeritus Director, Clemson University Arthropod Collection, South Carolina, USA, for collecting literature and encouragement. We are also grateful to Mr. R. Deepak, Miss. G. Padmavathi, Mr. S. Rajesh Kumar, and Mr. V. Rangaswamy, Research Scholars from Andaman and Nicobar Regional Centre, ZSI, Port Blair, for accompanying us in the field. Our thanks are due to Dr. P. Girish Kumar, Zoological Assistant, Hymenoptera Section, ZSI, Kolkata and Dr. S. Sheela, Officer-in-Charge, Central Entomological Laboratory, ZSI, Kolkata, for locating the material from Shillong for the study. We are thankful to Dr. Carl W. Schaefer, Emeritus Professor, University of Connecticut, Storrs (UConn), for linguistic review and editing the manuscript. We are also thankful to Mr. Angshuman Raha, Research Scholar, ZSI, Kolkata, for preparing distribution maps.

Figures

FIGURES 2 A – L. Metrocoris shillongensis sp. nov.: A, apterous female, dorsal view; B, macropterous female, dorsal view; C, macropterous male endosomal sheath, dorsal view; D, apterous female, left lateral view; E, left fore femur showing notch and tooth; F, male genital capsule, lateral view; G, macropterous male endosoma showing sclerites; H, macropterous male left paramere, lateral view; I, male dissected eighth abdominal segment, lateral view; J, macropterous male proctiger, dorsal view; K, apterous female abdominal tip, ventral view showing seventh sternal process; L, apterous female genitalia.