Ptilomera (P.) nagalanda Jehamalar & Chandra, 2018

Jehamalar, E. Eyarin, Chandra, Kailash, Basu, Srimoyee & Selvakumar, C., 2018, Review of Ptilomera (Ptilomera) (Hemiptera: Heteroptera: Gerridae) from India, with description of a new species, Zootaxa 4370 (5), pp. 501-518 : 509-511

Ptilomera (P.) nagalanda Jehamalar & Chandra , new species

( Figs. 4A–I )

Material examined. Holotype (apterous male): INDIA, NAGALAND, Peren District, Intanki River , 181 m, 25°39.883’ N, 93°30.686’ E, 23.iii.2017, Coll. C. Selvakumar.

Repository. The type specimen is deposited in the CEL, ZSI, New Alipore , Kolkata, West Bengal, India, Holotype Reg. No. 5788/H15.

Etymology. The new species is named after the Indian state Nagaland.

Diagnosis. The new species can easily be recognized by the presence of a fringe of fine short setae of different lengths in addition to a row of short black spines on the flexor region of the male mid femur reaching beyond the middle, and its sub-apex with a tuft of thick dark brown setae ( Fig. 4E ); the lateral process of the pygophore both dorsally and ventrally covered with dense setae ( Figs. 4C, D ); the presence of spines on the posterior region of the pygophore ( Fig. 4D ); and the presence of a longitudinal black stripe on the sublateral region of the mesonotum clothed with silvery white setae ( Fig. 4A ).

Description. Apterous male (holotype). ( Figs. 4A–I ). Body length 11.79; body width at mesoacetabulum 2.85.

Colour. Orange with black marks dorsally and pale yellowish brown ventrally; head laterally, anterior margin of pronotum at level below eye and vertex, lateral and sub-lateral region of meso-and metanota, acetabular region, abdominal terga I–VIII with silvery white marks; vertex of head with a pair of oblique black marks, base of head around trichobothrium with black round spot adjacent to eye; anterior and posterolateral region of pronotum black, mesonotum laterally with black mark, sublaterally with broad black longitudinal stripe and united anteriorly with lateral mark, linear and not reached posterior margin of mesonotum; mesoacetabulum laterally and posteriorly black; pleural region medially with linear yellow mark between mesopleural black mark and mesonotal lateral black mark; metanotum medially and laterally black; metaacetabulum with black-enclosed orange mark; dorsal face of fore femur with two longitudinal black stripes, one anteriorly and other medially, mesofemur dark brown, metafemur brown, coxa and trochanter of all legs yellowish brown; tibiae and tarsi of all legs black except fore tibia dorsally with yellow mark; connexivum yellowish brown; abdominal terga I–VII black, tergum VIII basally brown, apically black; proctiger brown, apical region of parameres black ( Fig. 4A ).

Structural characters. Head produced anteriorly, antennal tubercle prominent, head around eyes with black setae, inner margin of first antennal segment with sparse fine setae (more evident in alcohol), venter of head adjacent to eyes with 4–5 black setae, apex of third rostral segment with 4 erect sensory bristles two ventrally and other two dorsally; head length 1.49, width 1.75, minimum interocular width 0.56, eye length 0.84, eye width 0.53; antennal segment lengths I–IV 5.40, 1.28, 1.49, 1.19; rostrum reaching posterior margin of prosternum.

Anterior margin of pronotum straight, posterior margin medially concave; mesonotum sublaterally longitudinally depressed, medially with longitudinal sulcus indistinct anteriorly ( Fig. 4A ), posteromedian margin straight, posterolateral margin oblique; metanotum with posterior margin slightly concave, medially with longitudinal suture; venter of body with sparse minute black adpressed spines (more evident in alcohol) in addition to dense silvery white setae; fore trochanter clothed with short and long black setae; fore femur posteriorly with dense minute setae ventrally; basal region of fore femur with 5–6 medium sized thin setae; inner basal region of fore tibia with anterior small notch and posterior wide notch, each edge of notches with single denticle, apical process of fore tibia with few setae; venter of mid trochanter with 23–25 black spinules and sparse fine black setae, outer lateral region with 8 minute brown spines; mid femur clothed with minute black spines, flexor region of mid femur fringed with fine short setae of different length directed against hind femur in addition to row of short black spines, reaching beyond middle, tip of each seta directed downward, adjacent to which on ventral face with black spinules gradually disappearing apically, apex of mid femur with tuft of thick black setae directed upward and downward ( Fig. 4E ); mid tibial inner margin beyond middle fringed with dense straight setae directed downward; venter of hind trochanter with 22–24 minute black spines, dorsolateral region of hind trochanter with 5–9 black spines; metacoxa posterolaterally with prominent spine; hind femur longer than mid femur; hind tarsus fused; claws of all legs prominent; length of metasternum 0.39. Lengths of leg segments: fore leg: femur 6.31, tibia 4.52, tarsomeres I–II 2.51, 1.06; mid leg: femur 17.37, tibia 10.87, tarsomeres I–II 5.40, 0.53; hind leg: femur 20.64, tibia 11.67, tarsomeres I + II (fused) 0.31. Width of fore-, mid-, hind femora 0.93, 0.42, 0.34.

Connexivum small; posterior margin of tergum VII convex ( Figs. 4A, C ); 1ength of abdominal tergum 4.36, terga I–VIII 0.26, 0.41, 0.32, 0.32, 0.33, 0.42, 0.85, 0.74, combined lengths of terga I–VII 2.88, sterna II–VIII 0.32, 0.30, 0.32, 0.35, 0.37, 0.45, 0.49, combined lengths of sterna II–VII 2.10, posterior margin of tergum VIII with medium sized brown setae ( Fig. 4C ), sternum with long black setae ( Fig. 4D ). Genitalia: proctiger length (insitu) 0.54; lateral process of pygophore reniform, shape more evident in alcohol due to numerous long pale to dark brown setae dorsally and ventrally ( Figs. 4C, D ), posterior region of pygophore with numerous black adpressed spines ( Fig. 4D ); lateral margin of pygophore and proctiger with numerous fine setae; pygophore length, dorsal 0.21, ventral 1.68; proctiger wider than long, length 0.96, width 1.13 (after dissection), produced posterolaterally and medially, dorsally clothed with dark brown to black setae ( Fig. 4F ); paramere hook-like, apical part strongly bend upward, apical inner margin slightly concave, sparse setae throughout except base and apex, subapical outer region with fringe of numerous long dark brown to black setae, inner region beyond middle with short dark brown to black setae ( Fig. 4G ). Endosoma: dorsal view: basal sclerite (bs) with outer margin straight, inner margins irregular, highly sclerotised laterally; dorsal sclerite (ds) originates beneath basal sclerite, reaching near apical sclerite, basal end highly sclerotised, excavated forming lower short and upper long arms, fused behind, split before medially forming two long slender arms converging apically, apex highly sclerotised; median sclerite (ms) placed adjacent to dorsal sclerite, arising at level of subapex of lateral sclerite (ls) and apex overlaps apical sclerite; lateral sclerite placed below basal sclerite; accessory lateral sclerite (als) placed between subapices of lateral and median sclerites ( Fig. 4H ); lateral view: endosoma oval shaped; bs placed over base of dorsal sclerite; ds curved, base sub-triangular; as bow-shaped; ms broad, indistinctly fused with apical sclerite; ls linear, boat-shaped; als highly sclerotised with narrow base and broad apex; ventral sclerite (vs) thin and boat-shaped ( Fig. 4I ).

Macropterous male, apterous female and macropterous female: Unknown.

Distribution. Peren District, Nagaland, India, see Fig. 8A .

Comparative notes. Ptilomera nagalanda Jehamalar and Chandra , new species can be clearly recognized from all the known congeners from India by the absence of curly, intertwined dark brown to black swimming setae on the flexor region of the mid femur and the presence of silvery setae on the sublateral region of the meso- and metanota of the male ( Fig. 4A ). Ptilomera nagalanda is similar to P. fang Polhemus, 2001 from Thailand, but the new species can be easily distinguished from P. fang by the following characters: Silvery patches are present on the first abdominal tergum in P. nagalanda ( Fig. 4A ), whereas they are absent in P. fang ; the lateral wing of the pygophore dorsally and ventrally is clothed with white and black setae in P. nagalanda ( Figs. 4C, D ), whereas in P. fang the lateral wing of the pygophore has apical tufts of long black setae (see Polhemus 2001, p. 217, Fig. 1; Raruanysong et al. 2014, p. 106, Figs. 10, 11); the metasternum is distinctly shorter than the combined length of abdominal sterna II and III in P. nagalanda , whereas the metasternal length exceeds the combined lengths of sterna II and III in P. fang ; the flexor region of the mid femur basally has a fringe of short, almost straight and less dense setae reaching beyond the middle and the apex has a setal tuft ( Fig. 4E ) in P. nagalanda , whereas this setal fringe is absent in P. fang , although it has an apical setal tuft.

Figures

FIGURES 4A–I. Ptilomera nagalanda Jehamalar and Chandra, new species (apterous male, holotype): A, dorsal view; B, lateral view; C, abdominal apex, dorsal view; D, abdominal apex, ventral view; E, mid femur, ventrolateral view, showing setal fringe; F, proctiger, dorsal view; G, paramere, lateral view; H, endosoma, dorsal view, showing sclerites; I, same, lateral view, showing sclerites(als—accessorylateral sclerite;as—apical sclerite;bs—basal sclerite; ds—dorsalsclerite;ls—lateral sclerite; ms—median sclerite; vs—ventral sclerite).

FIGURES 8A–B. Distribution in India of: A, P. nagalanda Jehamalar and Chandra, new species; B, P.tigrina Uhler (Yellow triangles denote locality details from literature; red squares denote locality details of materials examined inthe present study).