Amphibologryllacris butmasi, Hugel, 2009

Hugel, Sylvain, 2009, Gryllacrididae and Tettigoniidae (Insecta, Orthoptera, Ensifera) from Espiritu Santo, Vanuatu, Zoosystema 31 (3), pp. 525-576 : 538-542

Amphibologryllacris butmasi n. sp. ( Figs 1B, C ; 2A, C, E, G ; 3A, B , E-G; 4A)

TYPE MATERIAL. — Holotype: Vanuatu. Sanma Province, Espiritu Santo Isl., Butmas , forêt sur plateau de Tankara, 15°21’56”S, 166°59’04”E, 600 m alt., nuit, Exped. Santo 2006, 13.X.2006, coll. S. Hugel, ♂ (SH-030) (MNHN-ENSIF2178).

Allotype: same locality and collector as holotype, nuit, 14.X.2006, ♀ (SH-026) (MNHN-ENSIF2185).

Paratypes: same locality and collector as holotype, nuit, 13.X.2006, 3 ♂♂ (SH-029, SH-033, SH-034) (MNHN-ENSIF2180, 2183, 2184). — Same locality, 16.X.2006, coll. T. Robillard, 1 ♂ (SH-027) ( MNHN- ENSIF2179).

Butmas E village, bord de chemin, Exped. Santo 2006, 16.X.2006, coll. S. Hugel, 2 ♂♂ (SH-031, SH-032) (MNHN-ENSIF2181, 2182). — Butmas, forêt sur plateau de Tankara, 15°21’56”S, 166°59’E, 600 m alt., nuit, Exped. Santo 2006, 16.X.2006, coll. T. Robillard, 1 ♀ (SH-028) (MNHN-ENSIF2186).

TYPE LOCALITY. — Vanuatu, Espiritu Santo Is., plateau of Tankara, near the village of Butmas.

DISTRIBUTION. — Vanuatu, Sanma Province, Espiritu Santo Isl., Butmas, Tankara plateau.

ETYMOLOGY. — After Butmas, the type locality.

HABITAT AND LIFE HISTORY TRAITS. — Some specimens of A. butmasi n. sp. have been observed during night hours rushing on branches and foliage (1-4 m) while exploring the surroundings with their tremendously long antennas.

DIAGNOSIS. — Compared to other Amphibologryllacris species. Size rather small for the genus: FIII: 10.2-11.8 mm, FW: 15.1-18.0 mm. Head: with very distinct black pattern (unlike A. ferruginea and A. cyaneoterminata lacking black pattern). Median and lateral ocelli clearly distinct ( Fig. 2E ), pink. Median ocellus wide, only slightly less wide than fastigium frontis ( Fig. 2E ; unlike A. oceanica having a small ocellus and A. cyaneoterminata with no visible ocellus in the ♀ holotype).

FW ( Fig. 4A ): M neither fused with Rs (unlike A. ferruginea , Fig. 4C ) nor with Cu (unlike A. painei , Fig. 4D ); M usually simple, Cu usually with 3 branches (2 bifurcations).

Legs: TI and TII not darkened, neither at mid length (unlike A. oceanica ) nor near the knee (unlike in A. dubia and A. cyaneoterminata ).

Male appendices cerciferae long, lying head-to-tail, side by side (processes short in A. ferruginea and, according to Karny [1935], similar to A. ferruginea in A. painei ). Male SGP with a distinct emargination ( Fig. 2G ; no emargination in A. ferruginea and A. painei ). Female sternite preceding the SGP (VII) forming a protrusion with an oval apex ( Figs 2A ; 3B ; sometimes bulging but not protruding in A. dubia , A. ferruginea and A. cyaneoterminata , Fig. 5 ).

Amphibologryllacris butmasi n. sp. is extremely close to A. macrocera and differs by (see Figs 2 ; 3E ): its shorter size (e.g., [see also Tables 1 and 2], FIII: 10.2-11.8 mm vs. 12.2-14.9 mm in A. macrocera ; FW: 15.1-18.0 mm vs. 17.5-21.7 mm in A. macrocera ; ovipositor 9.3-10.4 mm vs. 11.8-13.7 mm in A. macrocera ); FW with 2 or 3 precostal veins ( Fig. 4A ; usually 4 or 5 precostal veins in A. macrocera , Fig. 4B ); pronotum discus posterior sulcus well distinct, metazona bulging; male SGP with a distinct emargination ( Fig. 2G ; shallower emargination in A. macrocera : Fig. 2H ), styli shorter (length: 1.08 ± 0.02 mm vs. 1.35 ± 0.02 mm in A. macrocera ) and thicker than in A. macrocera . Amphibologryllacris butmasi n. sp. differs also from A. macrocera by its general darker coloration: head always with distinct black pattern, pronotum always encircled by a black margin; pronotum discus anterior sulcus and prozona darkened; sulci darkened on lateral lobes; FW always with numerous well smoked cells, femora always with black ventrally; abdominal tergites always black.

MEASUREMENTS. — See Table 2.

DESCRIPTION

In addition to generic characters. Body length: size small for the genus. Head ( Fig. 2E ): as broad or slightly broader than the thorax; fastigium frontis distinctly wider than scapus; face maximal width (in frontal view, below the eyes) 3.8 times (min: 3.5; max: 4.0; holotype: 4.0; allotype: 3.9) as wide as fastigium frontis (measured above median ocellus); median and lateral ocelli clearly distinct, median ocellus oval, wide as half of the fastigium frontis width. Thorax: pronotum: maximal width 1.1 times (min: 1.1; max: 1.2; holotype: 1.1; allotype 1.1) wider than maximal length; anterior margin convex (in dorsal view), arched; posterior margin strait (in dorsal view), almost horizontal; anterior sulcus deep on lateral lobes and well distinct on discus; posterior sulcus well distinct on discus; both sulci converging on lateral lobes; prozona elevated; metazona narrower than pronotum prozona, bulging; lateral lobe/discus angle sub acute (frontal view). Sternum ( Fig. 1B, C ; see Amphibologryllacris diagnosis): spines on mesosternum lateral lobes short with blunt apex, spines on metasternum inconspicuous, blunt. FW ( Fig. 4A ): with 2 or 3 precostal veins; R divided in 4 veins (3 bifurcations), rarely 5 veins (4 bifurcations); M simple (not divided); M sometimes (3/9) contacting punctually Rs, rarely contacting punctually Cu; Cu usually divided in 3 veins (2 bifurcations), rarely divided in 2 secondary veins (usually on one FW only, n = 2/9); 6 A veins, rarely 5 (1/9). HW exceeding slightly FW. TI and TII with usual spur formula (4 pairs of subapical + 1 pair of apical spurs ventrally, and one single apical spur on TII dorsally); subapical spurs of usual length (longer than tibia width). FIII 3.3 times as long as wide (range: 3.0-3.6 holotype: 3.1; allotype: 3.1); FIII ( Fig. 2C ) with 12-16 ventral inner spines (holotype: 13-14; allotype: 14-16); FIII with 7-12 spines (usually 9-11; holotype: 9-11; allotype: 9); TIII with 5-7 dorsal inner spines (holotype: 6-7; allotype: 6); with 6-7 ventral outer spines (holotype 6-7; allotype: 7).

Colour

Coloration more stable than in A. macrocera , although somewhat variable. Head: face with black patterns: paired spots on the face, the clypeus and around the median ocellus; continuous stripe above the clypeus; stripe on the antennal socket ventral margin; whole socket black; circular stripe surrounding the eyes posteriorly and converging in front of the occiput, without covering the occiput, median part of the occiput often with a black triangle pointing anteriorad. Ocelli pinkish. Scapus not darkened, except sometimes a lateral macula. Pronotum usually (16/ 19 specimens) strongly darkened, with black sulci and depressions; the fine margin surrounding the whole pronotum always black; prozona always darkened/black. FW with pale yellowish veins; with most cells smoked (except precostal area). HW smoked (except around transverse veinlets), rarely weakly (1/ 9 specimen). Legs always with black on femora ventral margin. Abdominal tergites always black.

SEXUAL DIMORPHISM

Apart from primary sexual characters, males smaller than females (TIII length 10.3 ± 0.2 mm, n = 7 vs. 11.1 ± 0.2 mm, n = 2).

Male

Terminalia ( Fig. 3A, B, F ) of Brunner’s type A ( Brunner von Wattenwyl 1888). T VIII not modified compared to preceding tergites. T IX not extended; end of tergite bent backwards/ downwards, with a minute median emargination on posterior margin. Appendices cerciferae ( Fig. 3F, G ) base enclaved between T IX lateral lobes and tergite end; appendices cerciferae with a process forming a long coiled spur with an acute apex, the spur bent basally; on dead specimens, both appendices cerciferae processes lying head-to-tail, side by side; the length and the angle of process bent variable within the species without discrete classes; SGP with a distinct emargination ( Fig. 3G ); styli short and thick.

Female

Sternite before SGP (VII): bearing a long process on anterior margin, directed backwards ( Figs 2A ; 3B ); reaching usually SGP base (depending on stuffing); process base weakly sclerotized, flat; process apex ladle-shaped with the concavity directed ventrally (the curvature depends on the preservation), the dorsal part strongly sclerotized.

STATUS OF AMPHIBOLOGRYLLACRIS BUTMASI N. SP.

Amphibologryllacris butmasi n. sp. specimens of the type series are displaying weak but clear differences with all A. macrocera examined specimens. Importantly, most of these differences are size or colour characters, and few are discrete characters (and these might be linked to size reduction).

As discrete characters are available and as for most of the non discrete characters, intermediate forms (i.e. between A. macrocera and A. butmasi n. sp.) are lacking ( Fig. 3E ), I decide to describe the specimens collected in Butmas as a new species.

Nevertheless, as most A. macrocera specimens have been collected at a low altitude (> 50 m) with distinct climatic conditions, it can not be entirely excluded that what I consider here as being a distinct species would represent an ecotype, involving allometric morphological changes.

Figures

FIG. 1. — Amphibologryllacris Karny, 1937, sternum: A, A. macrocera (Walker, 1869), left side view, note the pointing lateral lobes (arrows); B, C, A. butmasi n. sp., left side (B) and ventral (C) views. Abbreviations: see text. Scale bars: 1 mm.

FIG. 2. — Amphibologryllacris Karny, 1937 from Espiritu Santo: A, C, E, G, A. butmasi n. sp.; B, D, F, H, A. macrocera (Walker, 1869); A, B, ovipositor,right side view;C, D, left femur III side view;E, F, face;G, H, ventral views of male subgenital plate showing intraspecific variation (the four specimens on the right side are alcohol preserved). Scale bars: A-D, 10 mm; E-H, 1 mm.

FIG. 3.— Amphibologryllacris Karny,1937 from Espiritu Santo:A, B, F, G, A.butmasi n.sp.;C, D, A.macrocera (Walker,1869);A, C, ventral view of male terminalia; B, D, ventral view of female terminalia; E, distribution of male forewing widthas a function of femur III length, note the discontinuous measurement distribution on both species; F, male terminalia in posterior view (the subgenital plate removed),the right appendice cercifera is flipped downwards;G, ventral views of left appendice cercifera from two specimens,note the strong variation in shape.Abbreviations: see text. Scale bars: 1 mm.

FIG. 4. — Amphibologryllacris Karny, 1937, forewing: A, A. butmasi n. sp.; B, A. macrocera (Walker, 1869), holotype; C, A. ferruginea (Brunner von Wattenwyl, 1888), holotype (NHW); D, A. painei (Karny, 1935) (after Karny 1935). The grey dotted lines correspond to the claval fold. Scale bars: 10 mm.

FIG. 5. — Amphibologryllacris Karny, 1937: A-C, A. ferruginea (Brunner von Wattenwyl,1888),typespecimens (NHW);D-F, A.dubia (Le Guillou, 1841), non type female from Fiji Islands, identified by Karny (Vana-Levu, Jalave, 1926, ZMUH); A, ventral view of male holotype terminalia; B, ventral view of female terminalia; C, lateral view of male holotype left femur III; D, ventral view of female terminalia;E, right side view of female subgenital plate and ovipositor; F, lateral view of left femur III.Scale bars:A,B,D, 1 mm; C, E, F, 10 mm.