Signocoris nilgiricus, Heiss, Ernst & Baňař, Petr, 2013

Heiss, Ernst & Baňař, Petr, 2013, New apterous Carventinae from Sri Lanka and Southern India (Hemiptera: Heteroptera: Aradidae), Zootaxa 3647 (3), pp. 488-494 : 491-494

Signocoris nilgiricus n.sp.

(Figs. 7,9–10)

Material examined. Holotype male labelled: India (Madras) / Nilgiri, Hubical près Coonoor / 1600m, tamisages en forêt / 22 XI 1972 leg.C.Besuchet (44) // deposited in MHNG. This specimen is designated as holotype and labelled accordingly.

Diagnosis. This new species is easily recognized and differs from the only known species of the genus Signocoris kaszabi Hoberlandt 1958 by its smooth surface of fused anteriorly sloping mtg I+II, raised along posterior margin (there 4 large elevations in S. kaszabi ), by smooth surface of strongly posteriorly sloping tergal disk showing a triangular median elevation which overlaps mtgI+II anteriorly (rugose with a large subrectangular elevation and straight suture separating tergal plate from mtg I+II in S. kaszabi ), by rounded postocular lobes (dentiform in S. kaszabi ), and by spiracle II placed dorsolaterally on reflexed vltg II and visibible from above (lateral on a tubercle at a lower level, not visible). Compare figures 9,10 and 11,12.

Description. Apterous male, coloration of body blackish brown, antennae and legs light brown; surface smooth and submat at middle, lateral parts with rugosities and granulate elevations.

Head. Distinctly wider than long (34/26); clypeus narrow with a round dorsal tubercle, anteriorly free and as long as antennal segment I; genae thin, produced laterally of clypeus not exceeding its apex; antenniferous lobes short, lateral margins parallel, apex rounded reaching ½ of antennal segment I; antennae short 1.09x as long as width of head (37/34), segment I strongly bent at base and thickest, II club-shaped and shorter, III thinner as long as II, IV longest and fusiform with pilose apex; length of antennal segments I/II/III/IV = 9/ 8/8/11; granular eyes inserted in head; postocular lobes with a small round tubercle then roundly converging to constricted neck; vertex raised and rugose at middle, laterally delimited by carinate margins and a deep oval impression at a lower level. Rostrum arising from a slit-like atrium shorter than head, rostral groove deep closed posteriorly.

Pronotum. About 4.5x as wide as long (67/15); fused to mesonotum but separated by a deep transverse sulcus; disk smooth with 2 deep sublateral depressions, posteriorly elevated with 2 small round elevations, anterior margin ring-like laterally separated from anterolateral edge of carinate lateral margins by deep incisions; lateral margins posteriorly with a larger granulate lobe at a higher and a smaller one at a lower level, concavely converging anteriorly.

Mesonotum. Fused to metanotum; fusion line marked by a deep groove only lateral of large median hump-like elevation overlapping pronotum, this with a median longitudinal sulcus on granulate anterior face and smooth surface on posterior face sloping to a saddle-like depression of metanotum; lateral sclerites with punctures and rugosities, lateral margins raised and granulate seemingly doubled by an upper and a lower lobe.

Metanotum. Fused to mtg I+II, a thin transverse suture indicating fusion line; median saddle-like depression smooth and fused to elevated hump of mesonotum; lateral sclerites rugose with granulate raised and doubled lateral margins.

Mtg I+II. Completely fused to a smooth plate, at middle elevated posteriorly, sloping laterally.

Abdomen. Tergal plate strongly raised and fused to mtg I+II anteriorly but separated by a distinct furrow, a triangular elevation overlaps mtg I+II; surface smooth sloping posteriorly, lateral apodemal impressions marked by deep pits; deltg II+III fused, III–VII separated by sutures, their surface roundly depressed at middle, lateral margins granulate; vltg III–VII reflexed dorsally and visible as a rim along lateral margins; tergite VII strongly raised medially for reception of pygophore, spiracles II–VII placed lateral on reflexed vltg II–VII visible from above, VIII terminal on paratergites VIII.

Venter. Surface of fused median parts of pro-, meso-,metasternum and sternites II+III smooth, prosternum with a deep pit followed by elevated ridge on anterior half; sternites IV–VII separated by transverse sutures, their surface smooth at middle, rugose laterally; large sternite VII without pits or tubercles.

Legs. Slender and unarmed, femora and tibiae straight, trochanters fused to femora; preapical protibial comb developed; claws with thin pulvilli.

Genitalic structures. Pygophore declivous posteriorly, exposed surface granulate, paratergites VIII truncate posteriorly as long as pygophore. The single specimen was not dissected for the study of parameres.

Measurements. Length 3.25mm; width of mesonotum 84, of metanotum 86; width of abdomen acrosse tergite II – 89, III—84, IV—76, V—66, VI—55; width of pygophore 15.

Etymology. Refers to Nilgiri hills, the mountain range in Southern India where this new species was collected.

Discussion. The conspicuous body structures of this new species with humps and elevations on thorax and abdomen resemble those of other apterous Oriental Carventinae : Vientnamaptera Zhang et al. 2010 with 4 species recorded from Vietnam and Southern China (Bai, Heiss & Cai 2011) and the monotypic genus Signocoris Hoberlandt 1958 with S. kaszabi from Madura in Southern India.

Although the different general habitus and several characters mentioned in the diagnosis not shared by S. kaszabi , these might be sufficient for the erection of a new genus for S. nilgiricus n.sp.. We refrain here to propose this new genus, and assign the new species tentatively to Signocoris until more specimens are available for comparative studies.