Lebinthus bitaeniatus Stål, 1877

Robillard, Tony & Tan, Ming Kai, 2013, A Taxonomic Review Of Common But Little Known Crickets From Singapore And The Philippines (Insecta: Orthoptera: Eneopterinae), Raffles Bulletin of Zoology 61 (2), pp. 705-725 : 712-718

Lebinthus bitaeniatus Stål, 1877

( Figs. 10 , 11A–D , 12A–C , 13A, B , 14A–C , 15A–C , 16 )

Lebinthus bitaeniatus Stål, 1877: 50 ; Bolívar, 1889: 425; Chopard, 1968: 354; Robillard & Desutter-Grandcolas, 2004a: 275; 2006: 644; 2008: 67 (phylogeny and taxonomy)

Synonym names

Paraeneopterus bitaeniatus Saussure, 1878

Paraeneopterus bitaeniatus Saussure, 1878: 334 ; Brunner von Wattenwyl, 1898: 279; Chopard, 1968: 355

Lebinthus bitaeniatus – Robillard & Desutter-Grandcolas, 2008: 67 >> Paraeneopterus bitaeniatus , replaced by Lebinthus saussureii , synonym of L. bitaeniatus

Lebinthus saussureii Bolívar, 1889

Lebinthus saussurei Bolívar, 1889: 425

Paraeneopterus bitaeniatus – Chopard, 1968: 355

Lebinthus bitaeniatus – Robillard & Desutter-Grandcolas, 2008: 67> synonym of L. bitaeniatus

Discussion. — Most Lebinthus specimens showing lateral yellow bands along the whole body have generally been identified as L. bitaeniatus by previous authors. However, close re-examination using modern taxonomic criteria suggests that many different species are probably mixed under L. bitaeniatus , such as L. luae Robillard & Tan , new species from Singapore and South Sumatra, L. bifasciatus Chopard, 1951 from Australia and L. lanyuensis Oshiro, 1996 from Taiwan. Combined to close examination of morphology, acoustic analysis of calling songs ( Table 2) and molecular analyses reveal clear differences between L. bitaeniatus and L. luae .

Material examined. — Holotype (female): Philippines: Ins. Philipp., semper, 24-25/5-64 ( NHRM-ORTH0012705 ) (examined on photograph, see Fig. 10 ).

Other material examined. Philippines: 2 females ( BPBM) , Luzon, Los Banos, Mount Makiling , coll. C. M. Yoshimoto, 17 Sep.1959 ; 1 male ( BPBM) , Luzon, Los Banos, Mount Makiling , coll. C. M. Yoshimoto, 19 Sep.1959 ; 2 males ( MNHN: TR145 , 151 ) , 2 females ( MNHN: TR146 , 147 ) , 2 juveniles ( MNHN: TR15 , 154 ) , on leaf litter, 1 female ( MNHN: TR127 ) , on plant (h = 10 cm), 2 males ( UPLB MNH: TR144 , 228 ) , 3 females ( UPLB MNH: TR148 , 149 , 150 ) , 2 juveniles ( UPLB MNH: TR153 , 155 ) , leaf litter, 2 males ( UPLB MNH: TR142 , 143 ) , on low plant, Luzon, Los Baňos, Laguna, Mount Makiling , base, Flat Rock , West of Mulawin Creek , secondary forest, 14°08'50.2"N, 121°13'41.5"E, 244 m, coll. T. Robillard, 28 Jun.2011, all night ; 3 males ( MNHN: TR81 , 84 , 85 ) , leaf litter, night, 1 male ( MNHN: TR86 ) , on plant (h = 10 cm), night, 1 male ( MNHN: TR81 ) , leaf litter, day, 1 male ( MNHN-ENSIF3197 : TR124), call recording, leaf litter, day , 1 male ( MNHN-ENSIF3196 : TR266), call recording, on plant (h = 30 cm), day , 1 male ( MNHN: TR87 ) , on plant (h = 80 cm), day, 1 juvenile ( MNHN: TR107 ) , leaf litter, day, 1 male ( UPLB MNH: TR04 ) , 2 females ( UPLB MNH: TR105 , 106 ) , on plant (h = 30 cm), day, 1 juvenile ( UPLB MNH: TR282 ) , leaf litter, night, Luzon, Los Baňos, Laguna, Mount Makiling , base, secondary forest on campus, 14°09'12.9"N, 121°14'05.0"E, 168 m, coll. T. Robillard, 27 Jun.2011 – 3 Jul.2011 ; 1 male ( MNHN: TR230 ) , 1 female ( MNHN: TR233 ) , on plant (h = 30 cm), 1 female ( MNHN: TR235 ) , on plant (h = 1 m), 1 female ( MNHN: TR219 ) , on plant (h = 1.7 m), 1 male ( ZRC: TR227 ) , on plant, 1 female ( ZRC: TR231 ) , on plant (h = 1 m), 1 male ( UPLB MNH: TR229 ) , on plant (h = 30 cm), 1 male ( UPLB MNH: TR234 ) , 1 female ( UPLB MNH: TR232 ) , on plant (h = 1 m), Luzon, Los Baňos, Laguna, Mount Makiling , base, East of Mulawin Creek , secondary forest, 14°08'51,6"N, 121°13'46,7"E, 182 m, coll. T. Robillard, 29 Jun.2011 ; 2 males ( MNHN: TR181 , 182 ) , 1 female ( MNHN: TR183 ) , grassland, Luzon, Los Baňos , Laguna, arboretum, 14°09'52,8"N, 121°14'17,1"E, 45 m, coll. T. Robillard, 29 Jun.2011, all day .

Diagnosis. — Species similar to L. luae new species, but differing by general shape more slender, lighter colouration, with a yellow longitudinal band along the body thinner and underlined ventrally by a narrow black line; male genitalia differ by details and proportions and by strong M-shaped sclerotisation of ectophallic fold, absent in L. luae , but close to that of other species (ex: L. cyclopus Robillard , L. truncatipennis Chopard : Robillard, 2010).

Redescription. — Species of average size for the genus, of slender shape. Colouration contrasting, with brown and dark brown areas and with narrow dorso-lateral yellow longitudinal bands along the whole body ( Fig. 11A–D ). Head dorsum yellow brown with 6 dark brown longitudinal bands more or less distinct ( Fig. 12A–C ). Fastigium wider than long, setose, dark brown, apex yellow with two wide black spots on facial part almost touching each other. Scapes yellow and brown; antennae brown. Face variable, from yellow brown to darker brown. Epistomal suture yellow. Mouthparts yellow brown, including maxillary palpi. Lateral part of head with a yellow area posterior to eye, underlined by a black band, then progressively lighter from dorsal to ventral region. Pronotum: dorsal disk yellow brown to brown, slightly mottled with brown, with black spots and with short black longitudinal lines on posterior apex; lateral edges yellow. Lateral lobes dark brown to black dorsally and progressively lighter ventrally. Legs I and II light brown to yellow brown, femora with brown spots and longitudinal patterns, tibiae with rings. FIII brown, sometimes with dark spots and with striated dark patterns on outer faces; hind knees black; hind tibiae black with yellow rings. For all pairs of legs, Ta1 and Ta3 yellow basally, dark brown apically. Abdomen homogeneously dark brown dorsally, covered with golden setae, lateral edges with yellow or whitish longitudinal bands. Sternites yellowish brown, with dark brown patterns laterally. Cerci yellowish basally, with black rings near apex, their ventral side black.

Male: FWs not reaching abdomen mid-length ( Fig. 13A, B ). FW colouration: Cells and veins brown, not translucent; angle between dorsal and lateral fields forming a narrow band, whitish to yellow, including basis and distal part of CuA (rest of CuA dark brown), basis of MP, CuA/MP area, and half MA/MP area; lateral field with a thin black line underlying the yellow longitudinal band, then brown ventrally; small median fold not included in the pale longitudinal band. FW venation ( Fig. 13A ): 1A angle wide (>100°); stridulatory file with 138–144 teeth (m = 141, n = 2), located on transverse and longitudinal parts of 1A. CuP absent. Area posterior to plectrum strongly sclerotised. Harp wide, with a longitudinal fold near angle of 1A (claval fold?); with 1 harp vein, sometimes bifurcated distally. Distal part of CuA straight. Mirror (d1) not differentiated, resembling the other few cells of D alignment. Apical field absent, with no bifurcation of CuA posterior to diagonal vein. Lateral field with 5 strong longitudinal veins including MA, R and 3 more ventral veins; latero-dorsal angle made by MP; R without strong bifurcating veins. Subgenital plate elongate, clog-shaped.

Male genitalia ( Fig. 14 ): Pseudepiphallic sclerite trapezoidal, convex dorsally, its apex slightly trilobate, including a short median expansion and 2 small lophi barely individualised, slightly divergent and finely setose. Anterior margin bisinuated, with a median indentation. Rami short, half as long as pseudepiphallic sclerite. Pseudepiphallic parameres with a long sclerotised basis, trilobate, including a posterodorsal lobe and two ventral ones, the posterior lobe square, the anterior one curved anteriorly and pointed, slightly denticulate. Ectophallic arc complete and wide. Ectophallic fold wide and triangular, with a wide M-shaped sclerotisation; apex membranous. Ectophallic apodemes long and parallel, exceeding anterior margin of pseudepiphallus. Bases of ectophallic apodemes with a pair of ventral membranous expansions, with a small apical sclerite. Endophallic sclerite long, exceeding anterior margin of pseudepiphallus, convex dorsally, its posterior apex with a small median triangular expansion and with short thick lateral arms; endophallic apodeme made of a narrow median crest.

Female: FWs short ( Fig. 13B ), slightly longer than pronotum, slightly overlapping basally; dorsal field grey brown, with 5–6 (n = 4; HTF = 6) strong, orange brown parallel longitudinal veins and weak cream transverse veins. Lateral angle of FWs with a narrow yellow longitudinal band including a faint vein. Lateral field with 3–4 (n = 4) strong straight longitudinal veins.

Female genitalia: Ovipositor almost as long as hind femora; apex lanceolate, denticulate on dorsal edge ( Fig. 7B ). Copulatory papilla ( Fig. 7E ) conical, with a narrow basal sclerotised area on ventral face; apex rounded, sclerotised. Juvenile: Similar to adults in colouration, light brown.

Life history traits: L. bitaeniatus is a diurnal species living in secondary habitats or open areas in forest ( Fig. 15C ). Males sing from low plants above the leaf litter from early morning to dusk. Mating couples are generally observed during day and night on plant leaves or on top of the litter ( Fig. 15A–C ).

Behaviour. Calling song ( Fig. 16 ; Table 2): In the field (n = 2; t°C = 27.5–28.5°C) the calling song of L. bitaeniatus lasts for 11.3 ± 5.1 s and is made of very indented syllables. This echeme is organised in two parts, the initial one consisting of 35 ± 15 longer, well-spaced syllables (longer duration = 42 ± 10 ms and period = 273 ± 212 ms), the second part being a short trill made of 41 ± 8 shorter syllables set closer together (shorter duration = 11 ± 5 ms and period = 16 ± 6 ms). Each syllable is made of discrete pulses, produced by regular plectrum pauses, which in turn are caused by a discontinuous closing phase. Such a pattern produces a broad band spectrum between 12 and 30 kHz), with main energy centred at nearly 19.9 ± 1.3 kHz, which corresponds to the first and only peak of the spectrum.

Measurements. See Table 3.

Figures

Fig. 10. Female holotype of Lebinthus bitaeniatus in dorsal (A) and lateral (B) views; labels (C). Type deposited in Swedish Museum of Natural History, Stockholm. (Photographs by: Gunvi Lindberg & Kjell Arne, NHRS).

Fig. 11. Lebinthus bitaeniatus (A–D): A, B, male; C, D, female; A, C, dorsal view; B, D, lateral view. Lebinthus luae (E–H): E, F, male; G, H, female; E, G, dorsal view; F, H, lateral view. Scale bar = 1 mm.

Fig. 12. Head: A–C, Lebinthus bitaeniatus; D–F, Lebinthus luae. A, D, dorsal view; B, E, facial view; C, F, lateral view. Scale bar = 1 mm.

Fig. 13. Forewing venation in dorsal view: A, B, Lebinthus bitaeniatus; C, D, Lebinthus luae. A, C male; B, D, female. Scale bar = 1 mm.

Fig. 14. Male genitalia: A–C, Lebinthus bitaeniatus; D–F, Lebinthus luae. A, D, dorsal view; B, E, lateral view; C, F, ventral view. Scale bars = 1 mm.

Fig. 15. Lebinthus bitaeniatus (A–C), in Mount Makiling (Luzon, Philippines) on campus near UPLB MNH: A, female on plant at night; B, male courting a female during afternoon on leaf litter; C, view of secondary habitat. Lebinthus luae (D, E), in Labrador Park, Singapore: D, male and female mating on branch (h = 30 cm) in the afternoon; E, male and juvenile foraging on fallen fruit.

Fig. 16. Calling song of Lebinthus bitaeniatus. Oscillogram of 5 echemes (A); oscillogram (B) and sonogram (C) of 1 echeme; oscillogram (D) and linear power spectrum (E) of 1 syllable in the starting part of the echeme.

Fig. 7. Female genitalia: A–C, apex of ovipositor; D–F, copulatory papilla. A, D, Nisitrus vittatus; B, E, Lebinthus bitaeniatus; C, F, Lebinthus luae. Scale bars = 1 mm.