Svistella chekjawa, Kai & Robillard, 2012

Kai, Tan Ming & Robillard, Tony, 2012, Two New Cricket Species (Orthoptera: Gryllidae And Mogoplistidae) From The Mangrove Areas Of Singapore, Raffles Bulletin of Zoology 60 (2), pp. 411-420 : 412-417

Svistella chekjawa , new species

( Figs. 2–5 )

Material examined. — Holotype: male ( ZRC), Singapore, Pulau Ubin , Chek Jawa, along mangrove boardwalk, 27 Apr.2011, coll. M. K. Tan, J. J. Y. Chan, J.-Y. Sek, S. C. L. Chng, A. M. L. Ng & R. Ong.

Paratypes – Singapore: 3 males, 3 females ( ZRC), Jurong mangrove, 7 Nov.1976, coll. D. H. Murphy ; 1 male ( ZRC), Changi mangrove “on Sesurium ”, 15 Mar.1978, coll. D. H. Murphy ; 1 male, 3 females ( ZRC), Pasir Ris Park , Sungei Tampines, along mangrove boardwalk, 4 Mar.2011, 15 Apr.2011, 15 Sep.2011, coll. M. K. Tan ; 1 female ( ZRC), Pulau Ubin , Chek Jawa, along mangrove boardwalk, 27 Apr.2011, coll. M. K. Tan, J. J. Y. Chan, J.-Y. Sek, S. C. L. Chng, A. M. L. Ng & R. Ong ; 1 male ( MNHN), Pasir Ris Park , Sungei Tampines, along mangrove boardwalk, 17 Jun.2011, coll. M. K. Tan ; 1 female ( MNHN), Sungei Buloh Wetland Reserve , along mangrove boardwalk, 5 Aug.2011, coll. M. K. Tan & J. J. Y. Chan.

Diagnosis. — Similar to S. venustula , but differs by patterns of yellow colouration all over the body. Small

genitalial differences are expected although no genitalia was examined.

Description. — General appearance typical of the genus. Male and female habitus as Figs. 2A, B . Body pubescent. Head, together with eyes, wider than pronotum. Frontal rostrum flattened, about as wide as first antennal segment; with long setae. Vertex not flattened dorsally. Antennal segments pubescent. Eyes slightly elongated from dorsal view; slightly hemispheric from lateral view. Genae swollen, pubescent. Maxillary palpi elongated; last three segments of about equal length; apical segment triangular, longer than wide, sometimes significantly longer. Labial palpi with apical segment long and triangular. Pronotum wider than long, slightly narrowed anteriorly; pubescent with long setae, otherwise fairly smooth; sulci indistinct; anterior and posterior margins straight; dorsal disc flattened. Lateral lobes of pronotum longer than high, ventral margin straight, anterior and posterior angles obtuse. Hind wings absent. Fore tibiae with inner and outer tympana, both open and oval, of about equal size; fore and median tibiae sometimes with one to two inner apical spurs on ventral surface, otherwise fore and median legs unarmed ventrally. Tarsal middle segments with prominent adhesive pads. Hind femora with long straight setae along inner-ventro carinula and near the knees along outer-ventro carinula. Hind tibiae with three inner and three outer subapical spurs; two inner and two to three outer apical spurs, inner ones distinctly longer than outer ones. Cerci simple, tapering and long surpassing hind femora.

Male: Tegmina barely reaching abdominal apex (may surpass abdominal apex in dried specimens), but surpassing bases of cerci. Sclerotization of tegmina asymmetrical, the right one more sclerotized than the left one. Mirror larger than harp, longer than wide; within mirror with ovular vein, acute at base and apex. Harp as wide as long, with one sinuate harp vein. Diagonal sinuated. Stridulatory vein bow-shaped, more strongly curved in caudal area, with about 155 evenly distributed teeth (n = 1). Lateral field with five longitudinal veins, the two most ventral veins join the third most ventral vein, the first near apical area, the second near basal area. Last abdominal tergite simple ( Fig. 3A ). Epiproct transverse, wider than long; grooved medially; apex broadly emarginated ( Fig. 3A ). Subgenital plate with apex wide-roundedly excised ( Fig. 3B ). Male genitalia as in Fig. 4A . Pseudepiphallus deeply indented (three levels of indentation), separated into two lateral parts joined by an anterior sclerotized bridge between the bases of the rami. Posterior edges of pseudepiphallic sclerite with a ringe of strong setae. Posterior apex of pseudepiphallus forming thin divergent and sclerotized lophi. Pseudepiphallic paremeres trilobate, with two posterior lobes oriented dorsally and posteriorly, and a wide membranous lobe. Ectophallic fold forming a thin sclerotized virga. Endophallic sclerite elongated along dorsal cavity, with a median crest, long lateral arms and lateral apodemes.

Female: Tegmina not reaching abdominal apex and barely reaching bases of cerci. Female venation made of strong longitudinal veins, seven dorsal and five lateral. Last abdominal tergite setose, truncated with shallow triangular notch, with median furrow, with carinula on lateral margins. Epiproct setose, tongue-shaped, weakly transverse with furrow near each lateral margin ( Fig. 3C ). Subgenital plate with anterior margin straight, apex gently rounded ( Fig. 3D ). Ovipositor not surpassing cerci; its margins smooth, barely curved basally; middle part appears rugose, becomes slightly curved thereafter; ventral valves longer than dorsal valves; apex denticulate at dorsal and ventral margins and lateral ridges ( Fig. 3E ). Copulatory papilla small, conical and slightly slecrotized, apex membranous ( Fig. 4B ).

Colouration: Males and females with dark markings, exhibit sexual dimorphism. In fresh specimens, head (including scapes) and pronotum blue green in males, brown in females. First antennal segment brown in males and females. Vertex with thick transverse mottled black band with irregular margins, at times broken in middle. Face with pi-shaped dark marking, a small transverse dark band with dark spot on the sides above pi-shaped marking ( Fig. 2C ). Palpi with segments light, sometimes slightly dark at anterior and posterior margins. Pronotum light brown, densely mottled with dark patterns, with margins dark, most obvious along hind margin. Tegmina generally dark brown, basal and apical areas infumate white; male right tegmen coloured, posterior part of chords infumate white in males; lateral field dark with light margins; left tegmen transparent except lateral field; white infumation more distinct in males ( Fig. 2D ). Thoracic sternites white, slightly blue in males. Abdominal tergites dark brown (brown in females), darkening towards abdominal apex (appearing darker in dried specimens). Abdominal sternites in males light in middle, black at the sides with lateral margins yellow; light in females; last two sternites (including subgenital plate) completely black in males, light in females. Legs in both males and females generally light with dark markings. Fore and median femora with black bands near knees, sometimes longitudinal stripes on both inner and outer ventral surface; tibiae with black bands near knees; knees black; tarsi dark. Hind femora outer surface with black longitudinal stripe in middle, irregular black pattern above stripe and near knees ( Figs. 2E, F ); inner surface with two oblique black markings which intensify towards dorsal edge ( Fig. 2G ). Hind tibiae with faint dark bands near knees and at base of subapical spurs; dark apically. Middle and last segments of hind tarsi black. Ovipositor very light brown basally, dark brown in middle, brown thereafter.

Measurements: See Table 1.

Etymology. — The species is named after type locality Tanjong Chek Jawa, Pulau Ubin, Singapore; noun in apposition.

Biology. — In Singapore, this species appears to be restricted to mangrove areas ( Fig. 5A ). During the recent collections, adults and nymphs were found mostly on the leaves and branches of Bruguiera species (family Rhizophoraceae ) ( Fig. 5B ). Morphologically similar species were not encountered in other habitats. Additionally, salt particles were also found in some old specimens collected by D. H. Murphy.

Remarks. — The new species described above was already collected by D. H. Murphy during his Orthoptera collection in Singapore from the 1960s to 1980s, though the specimens remained unidentified prior to this study.

Figures

Fig. 2. Svistella chekjawa: Dorsal habitus of male (A) and female (B) paratypes; face of holotype in frontal view (C); dorsal field of tegmen of holotype (D); outside of the femur of holotype (E) and paratype (F) in profile view; inside of the hind femur of paratype (G) in dorso-profile view. Scale bars = 1 mm.

Fig. 3. Svistella chekjawa: Male abdominal apex of paratype in dorsal view (A) and holotype in ventral view (B); female abdominal apex of paratypes in dorsal (C), ventral (D), and profile (E) views. Scale bars = 1 mm.

Fig. 4. Svistella chekjawa: Male genitalia in dorsal view (A); female copulatory papilla and spermatheca (B). Scale bars = 1 mm.

Fig. 5. Svistella chekjawa: Male adult on the underside of a leaf of Bruguiera species (A); Bruguiera species found in Pasir Ris Park, along Sungei Tampines (B).