Ityocephala francoisi Bolívar, 1903

Hugel, Sylvain, 2009, Gryllacrididae and Tettigoniidae (Insecta, Orthoptera, Ensifera) from Espiritu Santo, Vanuatu, Zoosystema 31 (3), pp. 525-576 : 549-552

Ityocephala francoisi Bolívar, 1903 ( Figs 10 ; 15A )

Ityocephala francoisi Bolívar, 1903: 171 .

TYPE MATERIAL. — [ Vanuatu. Sanma Province, Espiritu Santo Isl. ], N. Hébrid. Santo (Fr.) [Manuscript] ; Ityocephala Francoisi Bol. [Manuscript]; Holotipo [printed red label]; MNCN, Cat.Tipos N°, 759 [printed red label] ; ♂ holotype ( MNM). High quality pictures examined .

TYPE LOCALITY. — Vanuatu, Sanma Province, Espiritu Santo Isl.

OTHER MATERIAL EXAMINED. — Vanuatu. (5 ♂♂, 5 ♀♀), Sanma Province, Espiritu Santo Isl., Butmas, forêt sur plateau de Tankara, bord de chemin, 15°21’56”S, 166°59’04”E, 600 m alt., sur plante 3 m de haut, nuit, Exped. Santo 2006, 13.X.2006, coll. S. Hugel, 1 ♀ (SH-044) (MNHN-ENSIF2196).

Peavot, forêt secondaire, 14°59’37”S, 166°47’04”E, 38 m alt., ancien jardin, rive S de la rivière, rive, nuit, Exped. Santo 2006, 20.X.2006, coll. S. Hugel, 1 ♂ (SH-037) (MNHN-ENSIF2189). — Same locality, date and collector, terrasse 2, sur plante 2 m de haut, nuit, 1 ♀ (SH-042) (MNHN-ENSIF2194). — Same locality and collector, terrasse 2, sur plante 5 m de haut, nuit, enregistrement, 21.X.2006, 1 ♂ (SH-036) (MNHN-ENSIF2188). — Same locality and collector, nuit, 21.X.2006, 1 ♀ (SH-040) (MNHN-ENSIF2192). — Same locality and collector, nuit, 23.X.2006, 1 ♂ (SH-039) ( MNHN- ENSIF2191). — Same locality and collector, nuit, 23.X.2006, 1 ♀ (SH-041) (MNHN-ENSIF2193).

Big Bay, Matantas, Vatthé Lodge, forêt autour de la grotte, 15°10’48”S, 166°57’27”E, 30 m alt., sous-bois, nuit, Exped. Santo 2006, 27.X.2006, coll. S. Hugel, 1 ♂ (SH-038) (MNHN-ENSIF2190). — Same locality and collector, nuit, 27.X.2006, 1 ♀ (SH-043), 1 ♂ (SH-045) (MNHN-ENSIF2195, 2197).

DISTRIBUTION. — Vanuatu, Espiritu Santo.

HABITAT AND LIFE HISTORY TRAITS. — All I. francoisi specimens have been found in relatively humid non coastal forests, in both preserved or slightly anthropized areas. Ityocephala francoisi seems to be strictly active during night hours.Adults seem mostly to stay on tree top, even on small trees.Females are sometimes observed in lower strata, and two specimens have been observed in oviposition in dead sections (diameter 3 cm, at 2-3 m) of living trees.

DIAGNOSIS (TENTATIVE, FEMALE ONLY). — Ovipositor ventral valves strait on the base (regularly curved in I. nigrostrigata female holotype); basally dorsal valves ( Fig. 10G ) less than twice as high as ventral valves (the base of ventral valves is much narrower in Ityocephala specimens from Tonga and Fiji).

MEASUREMENTS. — See Table 4.

REDESCRIPTION

Head ( Fig. 10A, B ). Less wide than pronotum; face, genae and occiput with minute depression giving a granulose aspect; occiput relatively flattened; eyes rounded, projecting; in dorsal view: fastigium flat, not projecting, truncated, 0.44 (min: 0.41; max: 0.47) times wider than head maximal width (eyes not included), 1.6 (min: 1.5; max: 1.7) times wider than eye maximal diameter, with a median incision; in frontal view, fastigium forming two trapezes separated by a vertical sulcus and separated from the frons by an arched sulcus; median ocellus weakly distinct, less wide than half inter scrobus width; frons/genae limit without carina; scapus less wide than eyes (frontal view), without spine.

Thorax. Pronotum ( Fig. 10E ): strongly granulose; 1.1 (min: 1.0; max: 1.2) times longer than wide (maximal width); discus anterior margin moderately convex, posterior margin rounded (convex) with a minute emargination on the middle; prozona and mesozona weakly arched, metazona flattened; discus anterior and posterior sulci well distinct, both sulci deep and converging on lateral lobes; without median and lateral carinae; lateral lobe ventral margin with a longitudinal bulging callosity; lateral lobe posterior ventral angle squared. Prosternum with usual paired spines: long, diverging, with blunt apex; mesosternum and metasternum with elevated lateral lobes pointing posteriorly.

Wings. FW opaque, with dense and thin reticulation; wider on the apex than on the base; apex obliquely truncated; HW inconspicuously exceeding the FW.

Legs.TI with uncovered oval inner and outer tympana; moderately inflated on tympanal area; with 2 dorsal carinae, more rounded ventrally; with2 ventral and 1 dorsal apical spurs on each side; with 7-9 inner preapical spurs; with6-8 outer preapical spurs, without dorsal spurs or spines.FI with a minute spine on each knee lobe; with 2 ventral carinae; with 1-5 (usually 2 or 3) spines on the inner ventral margin; without spines on the ventral outer margin. TII squared in cross section; with 2 ventral and 1 dorsal apical spurs on each side;with 7-11 (usually8-10) ventral anterior preapical spurs;with 6-8 ventral posterior spurs; rarely (2/ 10 specimens) with one minute dorsal posterior basal spur. FII with a minute spine on each knee lobe; with 2 ventral carinae; rounded dorsally; with 4-7 spines on the ventral anterior margin; without spines on the ventral posterior margin. TIII with 3 ventral and 1 dorsal apical spurs on each side; squared in cross section; with 9-12 spurs on the inner ventral carina; 13-17 spurs on the ventral outer carina; 14- 19 spurs on the inner dorsal carina; 13-19 spurs on the outer dorsal carina. FIII slender, elongated 8.0 (min: 7.2; max: 8.7) times longer than FIII maximal width; with on spine on each knee lobe; with 2 ventral carinae; with 12-18 (usually 14 or 15) spines on the inner ventral carina; with 7-14 spines on the outer ventral carina.

Colour

General coloration green (yellowish in dead specimens). Pronotum sulci and FW veins yellowish; HW hyaline except anterior field; ventral and internal area of F from yellow to orange.

VARIATIONS

Some specimens are displaying, to different degrees, black on: bulging callosity of pronotum lateral lobe ventral margin; TI and TII apex; FI and FII ventral area; FI and FII knee; TIII ventral margins; FIII ventral margins.

SEXUAL DIMORPHISM

Males are significantly smaller than females. Female body length 40% longer than male body length (23 mm vs. 32 mm); female FW about 20% longer than male FW. Females have usually less black patterns than males.

Male

Singing apparatus: left FW anal field as opaque and with the same dense reticulation than the whole FW; the file vein (A1) is well distinct (dorsal view); file with 73 (min: 70; max 76)lamellar teeth ( Fig.10H ). Right FW tympanum 1.76 (min: 1.74; max: 1.78) times as long as wide ( Fig. 10D ). Terminalia: tergite X (last) with a minute posterior emargination;epiproct acutely triangular, with a blunt apex;cerci with a minute apical teeth bent inwards. SGP without styli; elongated: c. 3 times longer than wide (depending on the specimen preservation); with rounded lateral lobes on the base; after this rounded base,with sub parallel sides;apex with a tongue-shaped emargination 0.20 (min:0.18; max: 0.22) times as deep as the SGP length; SGP separated by emargination on two apical lobes with rounded apex; apex slightly ladle-shaped ( Fig. 10C ).

Female

SGP as wide as long (min: 0.83; max: 1.19); rounded with a minute rounded apical emargination ( Fig. 10F ). Ovipositor strait on the base and strongly upcurved after mid length (particularly the dorsal margin); with denticulations in the curved section of ventral margin and minute denticulations in the apex of dorsal margin; apex pointing ( Fig. 10I ).

CALLING SONG ( FIG. 15A )

Males call during night hours,on tree top(usually above 3 m). Several males are usually singing alternatively. One male has been recorded in the field (SH-036, MNHN-ENSIF2188).At26°C,the call of this species consists of irregular widely spaced (every32.2 ± 16.7 s; min: 8.2; max: 96.3) echemes. Individual echemes last 443.8 ± 21.3 ms (min: 369.5; max: 488.3) and consists of 5 or 6 syllables. Th e calling frequency first harmonic peaks between 9.8-13.0 kHz.

Figures

FIG. 10.— Ityocephala francoisi Bolívar,1903: A, male face in frontal view;B, male vertex and occiput in dorsal view; C, male subgenital plate in ventral view; D, male right forewing anal field in dorsal view; E, male pronotum in left side view; F, female terminalia in ventral view; G, female ovipositor in right side view; H, SEM picture of male file. Scale bars: 1 mm.

FIG. 15.— Calling songs:A, Ityocephala francoisi Bolívar,1903 specimen MNHN-ENSIF2188,20H30,21°C,2 m high,Cardiodactylus sp. (Eneopterinae cricket) and Salomona redtenbacheri Brongniart,1897 are singing around (grey); B, C, Phaneroptera gracilis (Burmeister, 1838),the specimen MNHN-ENSIF2200 has been IR filmed in order to distinguish its call (black) from the other calls (Conocephalus sp.and crickets,in grey) 0H30,20°C; D, Furnia insularis (Stål, 1876),the specimen MNHN-ENSIF2311 has been IR filmed in order to distinguish its calls (arrows) from the background calls (Cardiodactylus sp. and Salomona redtenbacheri, see Fig. 20) 20H00, 21°C, 3 m from the specimen; E, Pseudorhynchus lessonii Serville, 1838, specimen MNHN-ENSIF2282, 19H40, 22°C. All songs recorded in situ.