Lathriobates manohardasi, Chandra, Kailash & Jehamalar, Eyarin, 2012

Chandra, Kailash & Jehamalar, Eyarin, 2012, Lathriobates manohardasi sp. nov. (Hemiptera: Gerromorpha: Gerridae) from Tamil Nadu, India, with a key to the species, Zootaxa 3186, pp. 64-68 : 65-68

Lathriobates manohardasi sp. nov.

Material examined: Holotype: 1 3 (apterous): Kallarakkavilai, Cherukole village, Kanyakumari District, Tamil Nadu, India, 3.x.2011, Coll: E. Eyarin Jehamalar; Paratype: 1 macropterous 3, 1 apterous Ƥ, 17.vii.2011, Coll: E. Hallings Raja Deasingh; 3 apterous Ƥ, 3.x.2011, Coll: E. Eyarin Jehamalar, paratypes same locality as that of holotype.

Description: Apterous male (Holotype) (PLATE I, Fig. A, C, D, E, L and N). Body length 2.84 mm; maximum body width (across mesoacetabula) 1.4 mm.

Colour: Yellowish to orange; three stripes dorsally on thorax piceous to black, central stripe extending to fused abdominal segments I and II (PLATE I, Fig. A); head orange with inner margin of eyes piceous; legs fuscous, femur of all legs luteous; fore femur with black streak; ventral side of body yellowish with grey tinge from pubescence.

Structural characters: Head: Measurements: Head length 0.39 mm., head width (across eyes) 0.71 mm; head width excluding eyes 0.32 mm; eyes extending posteriorly about one-fourth length of pronotum; length of eyes 0.34 mm; width of eyes 0.22 mm; head near to eyes piceous; length of antennal segment I-IV(0.58 mm, 0.37 mm, 0.92 mm, 0.83 mm); rostrum long and slender, its length 1.18 mm; head predominantly orange with two setae near anterior margin of eye and one seta behind lower region of eye; head with an obscure ridge medially of anterior region.

Thorax: Measurements: Pronotal length 0.26 mm; mesonotal length 0.91 mm; length of metanotum plus first two abdominal tergites 0.71 mm; prosternal length 0.25 mm; mesosternal length 1.52 mm. Three piceous to black stripes, central stripe straight and lateral stripes slightly curved; middle of mesopleuron with obscure stripe (Plate I, Fig. E); mesosternal stripe absent; pronotum shorter, mesonotum longer and metanotum fused with abdominal tergites I and II; metasternal scent gland opening indistinct.

Legs: Fore femur with piceous streak; femur luteous, tibia and tarsus fuscous; fore tibia slightly curved; fore tarsus with two claws and linear arolium shorter than the claws; both arolium and claws downwardly curved.

Relative length of legs (in mm):

Apterous Male Femur Tibia I Tarsal II Tarsal (Holotype) segment segment Fore leg 1.0 0.91 0.13 0.28 Mid leg 2.05 2.56 0.88 0.65 Hind leg 2.23 1.21 0.28 0.24

Abdomen: Tergites paler in hue except the apex, fuscous; abdominal tergites IV to VI subequal in length; sternites smaller except the last 3 abdominal segments; linear streak absent on tergites III-IV; parameres of males sickle- shaped with distinct basal part, paramere with setae on inner margin, only basal part slightly twisted (PLATE I, Fig. L); paramere length 0.32 mm, width 0.03 mm.

Macropterous male (Paratype) (PLATE I, Fig. H, I, J, O and P): Body length 2.79 mm (upto apex of abdomen); maximum body width (across apex of pronotal lobe) 1.28 mm.

Colour: Pronotum piceous with four orange spots, two small spots on the anterior region and another two large spots on the posterior region; clavus and corium of hemelytra piceous, membrane greyish black; head, legs and ventral side of body similar to that of holotype (PLATE I, Fig. H).

Structural characters: Head: Structure and colour similar to holotype.

Thorax: Pronotal lobe with four orange patches, two small at the anterior region and two large at the posterior region; length of pronotal lobe 1.17 mm, width of pronotal lobe (across humeral angles) 0.98 mm; length of ampliated area of pronotal lobe (apical area) 0.15 mm; prosternal length 1.07 mm; mesosternal length 1.4 mm.

PLATE I. A. Apterous male (holotype), B. Apterous female (paratype)—dorsal view, C. Male endosoma (holotype)—lateral view, D. Male endosoma (holotype)—ventral view, E. Apterous male (holotype)—lateral view, F. Apterous female (paratype)—ventral view, G. Apterous female (paratype)—lateral view, H. Macropterous male (paratype)—dorsal view, I. Macropterous male (paratype) showing dorsal genital segments, J. Macropterous male (paratype)—lateral view, K. Apterous female (paratype) abdomen—ventral view, L. Apterous male (holotype) paramere, M. Apterous female (paratype) genitalia, N. Apterous male abdomen—ventral view, O. Macropterous male (paratype) paramere—alternate view, P. Macropterous male (paratype) paramere.

PLATE II. A. Type locality habitat.

Legs: As that of holotype.

Hemelytra: Surpassing the apex of abdomen (PLATE I, Fig. H). Length of basal hard region of hemelytra 1.26 mm and apical delicate region 1.78 mm.

Abdomen: As that of holotype; parameres visible from outside (PLATE I, Fig. I), parameres similar to holotype; length of paramere 0.315 mm, width of paramere 0.036 mm (PLATE I, Fig. O and P).

Apterous female (Paratype) (n=4) (PLATE I Fig. B, F, G, K and M): Length 2.87; body width across mesoacetabula 1.52 mm.

Colour: As that of holotype.

Structural characters: Head: Structure and colour as that of holotype; measurements similar to holotype.

Thorax: Structure and colour pattern as that of holotype; measurements similar to holotype (PLATE I, Fig. B).

Legs: Colour similar to holotype; fore femur and fore tibia slightly curved.

Abdomen: Measurements little varied from holotype; VII abdominal sternum broadly excavated posteriorly (PLATE I, Fig. K). Only one specimen with slender white tubular process on left side of abdominal sternum IX.

Etymology: The name manohardasi refers to the second author’s Ph. D. Guide, Dr. S. Sam Manohar Das, Head, Dept. of Zoology, Scott Christian College (Autonomous), Nagercoil, Tamil Nadu, India.

Comparative notes: Lathriobates manohardasi sp. nov. is related to L. johorensis Polhemus & Polhemus and L. raja Distant in structure and colour. It differs from these two species by the presence of obscure median stripe of mesopleura (rarely dark), the paramere sickle-shaped and slightly twisted at base in male, and the absence of a linear streak on tergites III-IV and distinctive ventral endosomal sclerite. The setae on the inner margin of male parameres are not mentioned in the available literature of other known species of Lathriobates.

Repository: Lathriobates manohardasi sp. nov. is deposited in the Zoological Survey of India, New Alipore, Kolkata, Reg. No. 2502/H15 (Holotype: apterous male,), Reg. No. 2503/H15 (Paratype: 1 macropterous male), Reg. No. 2504/H15 (Paratype: 3 apterous female) and Reg. No. 2505/H15 (Paratype: 1 apterous female).

Discussion: The generic description of Lathriobates Distant, was first made from South India (Kerala) by describing the species Lathriobates raja Distant , synonymised under the name Gerris raja, Distant. Later on, it was named as Cryptobates raja ; now the name Lathriobates was given by Polhemus (2004). In their generic character Polhemus and Polhemus (1995) mentioned that the male parameres of Lathriobates are spiraled or strongly twisted. However, in Lathriobates manohardasi sp. nov., the parameres are slightly twisted at the base instead of being spiraled or strongly twisted. Polhemus and Polhemus (1995) described two species, L. rufus and L. johorensis. And now, fifteen years after their description, the new species L. manohardasi sp. nov. is described.