Diaphorocoris kiliyur Sites and Zettel

Sites, Robert W. & Zettel, Herbert, 2011, Waterfall-inhabiting Naucoridae (Hemiptera: Heteroptera) of southern India and Sri Lanka: Pogonocaudina Sites and Zettel, n. gen., and a review of Diaphorocoris with descriptions of two new species, Zootaxa 2760, pp. 1-17 : 14-16

Diaphorocoris kiliyur Sites and Zettel , NEW SPECIES

Figs. 10 , 13 , 16 , 18 , 20

Description. Macropterous male. Holotype, length 7.76; maximum width 4.72. Overall coloration dorsally dark brown with yellowish-brown head, pronotum, exposed connexiva, wide band on and at anterior end of embolium gradually narrowing to obsolescence near costal fracture; dense, dark punctation on head and pronotum ( Fig. 10 ). Ventrally, uniformly dark brown to black, with yellowish as perimeter band on prothorax, embolium, abdomen; and all leg segments except brown pro- and mesocoxae. Head, pronotum, and hemelytra generally covered with short, clavate setae; many clavate setae with fine hair emanating from tip.

Head length 1.20, maximum width 3.08, synthlipsis at posteromesal corner 1.00, lateral hyperoche with lateral margin shallowly concave; anterior margin of eye twice width of anterior margin of head laterad of eye; posterolateral part of eye protuberant and slightly extending over anterior margin of pronotum; five pairs of setal rosettes bordering inner margin of eyes, anteriormost pair slightly ventrad to anterior margin, posteriormost pair adjacent to mesal margin of eyes; posterior margin of head straight between eyes; labrum broad, evenly rounded; antennal proportions 5:6:13:9.

Pronotum broad, 2.9 x as wide as long, length at midline 1.48; maximum width at posterolateral corners 4.28; dark punctation diminishing laterally, scattered clavate setae with abruptly fine apical half and elongate, erect, black setae; elongate setae becoming light at lateral margin; setae more evident laterally in absence of dark pigmentation; anterior border between eyes dark brown, with transverse, irregular furrows; anterior half broadly flattened at midline and same height as anterior margin; distinctly flattened adjacent to lateral hyperoche of head; ventrally with yellow lateral coloration extending mesad halfway to coxal base. Scutellum dark brown with apex yellow, triangular with distinctly sinuate posterolateral margins, punctate, distinctly and broadly tumescent above level of clavus, tumescence diminishing anterolaterally, 1.7x as wide as long, width 2.80, length 1.68, clavate setae with abruptly fine apical half and concentrated laterally on tumescence and on yellow apex. Hemelytra finely punctate. Claval commissure length 1.04. Embolium length 3.16 (chord measurement), greatest width 0.72; lateral margin evenly curved, series of 18–23 short black spines; scattered clavate setae with abruptly fine apical half and elongate, erect, black setae; yellowish anterior band gradually narrowing posteriorly and becoming obsolete near costal fracture; with mesal incursion of yellowish white into dark brown at level of scutellar apex; dark coloration immediately anterior to mesal incursion extending halfway from embolar suture to lateral margin, separated from margin by distance of ≥5 times the length of a marginal spine ( Fig. 13 ). Metaxyphus broadly triangular, about as long as wide, acuminate posteriorly ( Fig. 16 ). Pro- and mesocoxae brown, metacoxae yellow with brown infuscation laterally, all other leg segments yellow. Hind tibia thin, maximum width 0.30. Other leg measurements as follows: foreleg, femur 1.08, tibia 1.56, tarsomeres 1–2 (0.16, 0.16); middle leg, femur 1.68, tibia 1.20, tarsomeres 1– 3 (0.12, 0.24, 0.24); hind leg, femur 2.20, tibia 2.18, tarsomeres 1–3 (0.28, 0.76, 0.70).

Abdomen dorsally with margins of III and IV with 2–8 small, stout black spines; scattered marginal black hairs denser posteriorly, with group of very long black hairs ¼ distance from posterolateral corner; faint brown coloration at base of very long hairs separated from dark brown coloration beneath wings; ventrally with marginal spines on III–VI and brush of elongate light colored hairs. Posterior margin of mediosternite III straight, IV concave, V strongly concave, VI slightly convex, VII straight, VIII straight. Strong brush of midventral brown hairs beginning on III and continuing to posterior end of abdomen. Posterior margin of laterosternite V shallowly concave. Aedeagus elongate, linear, right margin gently arcuate, left side angled to apex in distal 1/5, finely granulate in distal half; parameres symmetrical, anteromesal corners rounded, mesal margins flat, posteromesal corners rounded and overlapping straight anterior margin of sternum IX of genital capsule ( Fig. 18 ); pygophore punctate, with fine setae.

Macropterous female. Paratype. Length 7.81; maximum width 4.74. Similar to male in general structure and coloration except as follows; front tarsus one-segmented; pad of hairs on middle tibia reduced; posterior margin of mediosternite V and VI straight; posterior margin of laterosternite V broadly convex; subgenital plate (VII) about as long as wide, lateral margins convergent, posterior margin shallowly concave, posterolateral corners broadly rounded; valvulae extending beyond apex of subgenital plate ( Fig. 20 ).

Diagnosis. Diaphorocoris kiliyur can be recognized by its size, ventral coloration, and shape of the metaxyphus. Specifically, it can be distinguished from D. dubreuili by its much smaller size, and from D. punctatissimus and D. arunachalami by the dark brown to black ventral coloration: the dark color is darkest laterally where it abuts the yellow marginal band. The latter two species have a lighter brown ventral color. The broader metaxyphus also is diagnostic. Leg and lateral abdominal spination is slightly less robust and the hind tibia is more slender than that of D. arunachalami . The dark coloration of the embolium immediately anterior to the distal mesal incursion of the yellowish-white marginal coloration extends only halfway from the embolar suture to the lateral margin, and the marginal vestiture of the embolium is a row of short, black spines. The black, upright, clavate setae generally have an abruptly finer distal section. The latter feature was not observed on the congeners, although the fine hairs are easily broken off and might actually exist.

Discussion. This species occurred syntopically with D. arunachalami and Pogonocaudina indica at Kiliyur Waterfall. Specifically, it was found on near-vertical wet rocks of the waterfall among algae and mud where water flow was minimal or undetectable.

Etymology. This species is named for the waterfall in which it was discovered.

Repositories. The male holotype and a female paratype are deposited in the National Zoological Collection, Zoological Survey of India.

Material examined. Holotype, macropterous male, and paratype, macropterous female: INDIA: Tamil Nadu: Kiliyur Waterfall, Yercaud, N 11o 47.770', E 78 o 12.066', elev. 1188 m, 11 March 2010, L-1129, M. Arunachalam, S. Sundar, M. Muralidharan, P. Sivakumar, C. Selvakumar, T. Sivaruban, wet rocks of waterfall.

Figures

FIGURES 9 – 10. Habitus photographs of (9) Diaphorocoris arunachalami n. sp., (10) Diaphorocoris kiliyur n. sp.

FIGURES 11 – 14. Right embolium of macropterous (11) Diaphorocoris arunachalami n. sp., (12) Diaphorocoris dubreuili Montandon, (13) Diaphorocoris kiliyur n. sp., (14) Diaphorocoris punctatissimus (Kirby).

FIGURES 15 – 16. Metaxyphus of (15) Diaphorocoris arunachalami n. sp., (16) Diaphorocoris kiliyur n. sp.

FIGURES 17 – 18. Male genital capsule with aedeagus and parameres of (17) Diaphorocoris arunachalami n. sp., (18) Diaphorocoris kiliyur n. sp.

FIGURES 19 – 20. Ventral aspect of posterior abdominal segments of females of (19) Diaphorocoris arunachalami n. sp., (20) Diaphorocoris kiliyur n. sp.