Metrocoris deceptor Basu, Polhemus and Subramanian

Basu, Srimoyee, Polhemus, D. A., Subramanian, K. A., Saha, G. K. & Venkatesan, T., 2016, Metrocoris Mayr (Insecta: Hemiptera: Gerridae) of India with descriptions of five new species, Zootaxa 4178 (2), pp. 257-277 : 267-269

Metrocoris deceptor Basu, Polhemus and Subramanian , NEW SPECIES

Figs. 45–55

Metrocoris quynhi Tran & Zettel 2005 : Basu, Subramanian, Valarmathi & Saha, 2015: 98.

Material examined. Holotype: Apterous male: INDIA, West Bengal, Darjeeling District , Rishi River , Rishikhola , 27.17357°N, 88.631104°E, 23.III.2013, coll. S. Basu, deposited at the NZC, Zoological Survey of India, H.Q., Kolkata ( NZSI) Reg. No. 4643/H15.

Paratypes: INDIA, West Bengal: 23 apterous males, 16 apterous females, same data as holotype ( NZSI) ; 1 female, 7 nymphs, Darjeeling District, stagnant pool beside Rishi River, Rishikhola , 27.169677°N, 88.635109°E, 23.III.2013, coll. Srimoyee Basu ( NZSI) ; 5 males, 4 females, 1 nymph, Darjeeling District, Teesta River, Chitre Bridge , 22.III.2013, coll. S. Basu ( NZSI) ; 3 males, 4 females, 3 nymphs, Darjeeling District, Manjukhola, Phuguri tea estate, 26.85575°N, 88.2091°E, 21.III.2013, coll. S. Basu ( NZSI) ; 2 males, 4 females, 11 nymphs, Darjeeling District, Falls near Bunkulung , 26.86776°N, 88.22882°E, 20.III.2013, coll. S. Basu ( NZSI) ; 3 males, 5 females, Darjeeling District, Srikhola , 27.132452°N, 88.076729°E, 4.V.2013, coll. S. Basu ( NZSI) . Sikkim: 3 apterous males, 4 apterous females, West Sikkim, Martham village, Hee Bermiok , 3.X. 2013, coll. S. Basu ( NZSI) ; INDIA, Himachal Pradesh: 1 male, 3 females, 5 nymphs, Kangra district, Panthend village near Saibaba Mandir , Baijnath , 32.0227°N, 076.38743°E, 3117 ft, 13.09.2014, coll. Dr. K. Valarmathi ; 9 males, 9 females, 6 nymphs, Kangra district, Shahpur, Teh , Rajol Road , Rajol River , 32.10350°N, 076.14915°E, 14.09.2014, coll. Dr. K. Valarmathi ( NZSI) Reg. No. 4644/H15 to 4651/H15.

Discussion: Basu et al. (2015) recorded Metrocoris quynhi Tran & Zettel from India based on specimens taken in Himachal Pradesh and West Bengal, providing a detailed re-description and photographs of the taxon. However, a more critical examination of the specimens involved has revealed that they represent a new species in the Metrocoris anderseni species group. Therefore, the description and figures provided by Basu et al. (2015) depict this new species, which we have named Metrocoris deceptor .

Description. See detailed description in Basu et al. (2015) (as Metrocoris quynhi ). Only diagnostic characters are repeated here.

Size: Male body length 6.10–6.90 mm, maximum body width 2.64–3.0 mm. Female body length 5.30–6.72 mm, maximum body width 3.27–3.40 mm. Measurements of male and female leg segments given in Table 7 and 8.

Male foreleg: Fore femur ( Fig. 48 ) strongly incrassate, ratio length/width: 3.22 (2.68/0.83), constricted on apical third, lacking ventral indentation, bearing bifid sub-apical tooth. Fore tibia with inner margin bearing subbasal prominence.

Male genitalia: Pygophore ( Fig. 51 ) elongate, narrowed centrally with lateral margins concave, expanded distally, bearing prominently produced anterolateral angles, apex truncate. Proctiger ( Fig. 52 ) elongate, distal portion slender, apex broadly rounded. Paramere ( Fig. 53 ) elongate, projecting laterally far beyond genital segment, strongly bent, basal lobe with prominent angular projection in inner margin, distal arm slender, apex blunt.

Etymology. The name “ deceptor ” refers to the fact that this species at first appeared to be a known taxon, but was actually undescribed.

Comparative notes. Metrocoris deceptor sp. nov. seems to be most closely related to M. atlas Zettel (2011b) , described from two male specimens taken at Alaungdaw Katthapa National Park in Myamnar. Our new species has an elongate male paramere similar to M. atlas , but this structure is more sharply bent forming a nearly right angle (versus an approximate 45° angle as shown in Zettel’s illustration for M. atlas ) and lacks the small folding at the apex. As noted by Zettel (2011b), the male pygophore of M. atlas lacks the constriction characteristic of species in the M. anderseni species group, whereas such a constriction is present in M. deceptor , with the apex of the pygophore consequently more enlarged and bearing angular lateral expansions, which are lacking in M. atlas . In regard to the internal male genitalia, the lateral sclerites of the endosoma are larger, longer, and of slightly different shape in M. deceptor in comparison to the figures provided for M. atlas in Zettel (2011b) , although the latter are somewhat diagrammatic line drawings in contrast to the photographs provided for these structures in M. deceptor by Basu et al. (2015); thus, such comparisons may not be accurate. The structure of the male fore femur is similar in both species, but both sub-apical teeth are subequal in size in M. deceptor , rather than the distal tooth being obviously larger as in M. atlas . Finally, in regard to coloration, the black markings on the mesonotum are much thicker and more well-developed in M. deceptor , and antennal segment I is dark brown to black except at the extreme base, versus entirely pale except at the extreme apex in M. atlas .

Metrocoris deceptor also exhibits many similarities to M. anderseni , described by Chen & Nieser (1993a) from Uttar Pradesh, India. The male paramere in M. anderseni is strongly bent as in M. deceptor , but the ventral margin is far more strongly arcuate, the distal arm is shorter, and the apex expanded to form a small head (see Figs. 72, 73 in Chen & Nieser 1993a). The shape of the ventral sclerite of the endosoma in M. andersoni as depicted by Chen & Nieser (1993a) is also of very different shape from that in M. deceptor . The posterolateral angles of the male pygophore are also more pronounced and angular in M. deceptor than in M. anderseni .

Although previously confused with M. quynhi by Basu et al. 2015, the paramere shapes of the two species are very different, with that of M. quynhi being curved upward commencing on the distal one-fourth, while the curvature in M. deceptor commences near the midpoint, such that the upward-directed portion of the distal arm beyond the point of curvature is over twice as long in M. deceptor as in M. quynhi . Other characters separating M. quynhi from M. deceptor include female mediosternite VII, which projects posteriorly beyond the flanking lateral lobes of sternum VI in M. deceptor , rather than being even with them as in M. quynhi ; the coloration of the mesonotum in M. deceptor , which has the black markings broader and more pronounced than in M. quynhi ; and the coloration of male abdominal tergum VIII, which has a prominent longitudinal pale mark centrally on the posterior half in M. deceptor that is lacking in M. quynhi . Among the remaining species in the M. anderseni species group, M. deceptor is easily separated from M. falcatus Chen & Nieser and M. genitalis Chen & Nieser , by the shape of the male paramere, which is sharply bent centrally rather than distally, and has the distal arm beyond the bend far more elongate than in than in either of these two species.

Figures

FIGURES 45 – 55. Metrocoris deceptor sp. nov. 45. Dorsal view of apterous male; 46. Dorsal view of apterous female; 47. Ventral view of apterous male; 48. Ventral view of fore femur and fore tibia; 49. Male sternum including genital segments; 50. Female sternum; 51. Dissected pygophore with paramere of male; 52. Proctiger (dorsal view) of male; 53. Male paramere; 54. Dorsal endosomal sclerite; 55. Male endosoma showing sclerites.