Chremistica ribhoi Hajong & Yaakop

Hajong, Sudhanya Ray & Yaakop, Salmah, 2013, Chremistica ribhoi sp. n. (Hemiptera: Cicadidae) from North-East India and its mass emergence, Zootaxa 3702 (5), pp. 493-500 : 494-497

Chremistica ribhoi Hajong & Yaakop , new species

( Fig. 1 )

Type material: Holotype male: North-East India: Near Siden village, alt. 432 m a.s.l., 25˚51’37.1’N, 091˚51’16.3’E, 9. vi.2006.(ZSI, Kolkatta). Paratypes: North-East India: Lailad, near Nongkyllem Wildlife Sanctuary: 23 males and 7 females, alt. 416 m, 25˚ 55’09.7’ N, 091˚ 46’25.0’ E, 17.vi.2006.

Etymology. The species name is derived from the locality from where the type specimen was collected.

Description. Head. Head slightly longer than half the distance between eyes. Postclypeus moderately prominent with black transverse stripes and castaneous medial band with white pubescence in ventral grooves. Lateral part of anteclypeus black, white hirsute, medial keel dark brownish. Gena hirsute, mandibular plate black and densely hirsute. Supra antennal plate light brownish, ventral lobe black, two fuscous spots on either side of lateral ocelli. Remaining part of head black. Antennal pedicel brownish, rest of antenna pale or dark castaneous, length 3 mm. Whitish hairs behind eyes in socket margins. Rostrum castaneous, medial line black with black top, reaching middle of hind coxae.

Thorax. Anterior margin of pronotum castaneous, rest of head black with a median brownish fascia, a curved transverse ridge over anterior anchor spot extending to paramedian oblique fissure. Pronotal collar castaneous. Mesonotum with paramedian and lateral obconical fields and central mark black. Median point of central mark extending anteriorly far beyond mid-length of mesonotum disk and fused with inner medial margins of paramedian obconical fields. Cruciform elevation dark castaneous.

Legs. Coxae brownish with black spots on hind coxae, lightly hirsute with white hairs, femora brownish, hirsute with whitish hairs, one femoral spine on anterior and one on posterior lower margin of front femora. Ventral part of middle and hind femora with long whitish hairs. Tarsi brownish with black tarsal claws.

Wings. Fore and hind wings hyaline without infuscation. Basal cell pale yellowish. Radial vein ochraceous, subcostal vein black on apical half, light on basal half. Basal venation yellowish castaneous and apical venation dark

Male operculum (Fi g. 2). Pale brown, apices broadly convex, not reaching posterior margin of second abdominal sternite. Lateral margin curled down. Lateral part whitish tomentose. Medial margins of opercula overlapping.

Male abdomen. Blackish dorsally with a pair of oblique white spots on the third abdominal tergite and a pair of whitish tomentose spots on the eighth tergite, all tergites with scattered brownish pubescence which is denser on lateral sides. Sternites brown with whitish pubescence.

Male genitalia (Fi g s 3 & 4). Description of pygofer is based on Yaakop et al. (2005). Pygofer oval. Lateral pygofer lobe short, dark apices thickened and bent inwards, basal pygofer lobe small. Uncus medium-sized, slightly curved downward, apex square shaped, median clasper lobes darkened, triangular, and well developed with pointed apices. Aedeagus curved ventrally at tip. Basal plate convex, inner margin of pygofer lobe with rows of paired hairs. Apex of uncus hirsute.

Female operculum ( Fig. 5). Pale castaneous, posterior margin concave almost reaching second sternite margin, laterodistal corner blunt, surface covered with whitish pilosity, anterior area of operculum raised and posterior marginal area flat. Meracanthus blunt and crossing posterior margin of second sternite.

Female abdomen: Dorsal surface black, golden pubescence on lateral part of tergites, transverse wrinkled line on 3rd,4th, 5th and 6th tergites with a break on the middorsal area of each tergite. Tergite 8 brown with a medial black band. Tergite 8 and 9 with golden hirsute on posterior margins. Ventral surface brown, lateral margin of sternite with white pubescence.

Measurements. Male (n=5): length of body: 25-28 mm; width of head: 11 mm; length of tegmen: 36-40 mm. Female (n=5): length of body: 25-26 mm; width of head: 11 mm; length of tegmen: 36-37 mm.

Distribution ( Fig. 6 ): Ri Bhoi district in Meghalaya, North-East India.

Discussion. Only two species of Chremistica are recorded from the Indian subcontinent ( Bregman, 1985), they belong to the Chremistica tridentigera species group. The species of Chremistica are tentatively grouped into four species groups viz, the martini, coronata, tridentigera and pontianaka species groups. Bregman (1985) redescribed four species of the tridentigera group: C. seminiger ( Distant, 1909) , C. mixta (Kirby, 1891) , C. umbrosa (Distant, 1904) and C. tridentigera (Breddin, 1905) , and described three new species viz., C. minor , C. biloba and C. siamensis .

The tridentigera group is represented in India by only one species, Chremistica seminiger from Nilgiri Hills in Western Ghats of south India. The other species viz C. mixta (Kirby, 1891) is reported further south from Sri Lanka. C. seminiger is recognized by the presence of a pair of white spots on the third and the eighth abdominal segments and in the male genitalia by the lateral inner lobe which is more than 3 times as long as wide. Based on the genital structure of Chremistica ribhoi sp. nov which has a little broader and shorter lateral pygofer lobe, the new species can be placed in the pontianaka group.

The male of Chremistica ribhoi sp. nov. is distinguished from Chremistica seminiger by the smaller size of the body (25-28 mm) as compared to 40-42 mm in C. seminiger . The white spots on the third abdominal segment are prominent but the spots on the 8th abdominal segments are very pale. In the male genitalia, C. seminiger also totally differs from C. ribhoi by having a very long lateral inner pygofer lobe, a large, long and slightly downwardly curved uncus lacking a median furrow and with a broadly rounded apex and by the claspers which are strongly developed, triangular, flat, ochraceous to brownish black with some brownish hair ( Bregman, 1985).

C. ribhoi has short lateral pygofer lobes with dark, thickened and inwardly bent apices. Basal pygofer lobes are small and uncus is medium-sized, slightly curved downward, apex square shaped. The claspers are well developed and triangular in shape ( Fig. 3 ). The blunt ochraceous process present at both the lateral clasper margins as described for the Nilgiri specimen is totally lacking in this species. The genitalia of C. ribhoi also differs from C. mixta , which has a large broad uncus and and a weakly developed claspers.

Another species belonging to Chremistica viz. C. germana was reported from Burma (Distant, 1888). Metcalf, (1963) in his catalogue of Homoptera, Cicadidae , mentioned the distribution of C. germana as South E. Asia including India, however no actual report on the occurrence of Chremistica germana in India is available, although there is the possibility of a westward extension of this species from Southeast Asia including Burma and Thailand to India via the ‘Assam Gateway’. A comparison of the genitalia of C. ribhoi with the genitalia of C. germana described by Salmah et al. (2004) shows them to be different altogether.

The new species of Chremistica described from Thailand by Boulard (2002, 2005, 2006, 2007, 2009, 2012) viz. C. moultoni ( Boulard, 2002) , M. mussarens ( Boulard, 2005) , C. bimaculata inthanonensis ( Boulard, 2006) and C. sibilussima ( Boulard, 2006) , C. atratula ( Boulard, 2007) , and C. phamiaangensis ( Boulard, 2009) have not been reported so far from areas other than Thailand including Burma and India and therefore probably might be endemic to Thailand. Further C. ribhoi can also be separated from these species in terms of differences in genital structure, body size and coloration. In C. bimaculata , the uncus is longer than in C. ribhoi . In C. moultoni , the uncus is smaller and the aedeagus is elongated and bended compared to C. ribhoi . It differs from C. sibilussima , which has a greenish body coloration. Similarly, compared to C. atratula , it has a shorter pygofer. It also differs from the new species C. sueuri described by Pham (2013), which has a bifurcate uncus while the pygofer lobes are elongated and acute apically.

Figures

FIGURE 1. Chremistica ribhoi new species, male.

FIGURE 6. Distribution of Chremistica species in the Indian subcontinent.

FIGURES 3 – 4. Chremistica ribhoi, scanning electron micrographs of male pygofer. 3, ventral view; 4, lateral view.