Phaeogryllus Bolivar, 1912

Hugel, Sylvain, Warren, Ben H. & Desutter-Grandcolas, Laure, 2021, The Phalangopsidae crickets (Orthoptera, Grylloidea) of the Seychelles Archipelago: Taxonomy of an ecological radiation, Zootaxa 5047 (3), pp. 201-246 : 222-223

Genus Phaeogryllus Bolivar, 1912

( Figs 10–12 )

Phaeogryllus Bolivar, 1912: 285 .

Type species. Phaeogryllus fuscus Bolivar, 1912 , by monotypy .

Distribution. South Western Indian Ocean, endemic to granitic Seychelles.

Emended diagnosis. Within the Seselini Hugel and Desutter-Grandcolas, n. tribe, middle-sized but wide crickets, with uniform dull-brown coloration; cuticula hardly shining. TI with both inner and outer tympana. Male. FWs long and coriaceous with strong longitudinal veins and weaker transverse veins, without glandular structures. Tergites not glandular. Paraprocts longer than epiproct, wide and deeply concave distally. Male genitalia: lateral margins of pseudepiphallic sclerite convex in dorsal view; median lophi very closely set, making a very narrow apex compared to pseudepiphallic sclerite, separated by a truncated V-shaped emargination. Rami articulated with pseudepiphallic sclerite, with very thin apex. Dorsal sclerite of pseudepiphallic paramere well-sclerotized, rounded; ventral sclerite with sigmoidal base, the inner part smaller with teeth on inner and distal margins, the outer part larger and thicker, with regular margins. Ectophallic fold elongate but not reaching pseudepiphallic distal margin; sclerotized dorsally. Ectophallic apodemes regularly wide, somewhat longer than the sclerotization of epi-ectophallic invagination, and regularly divergent. Female. Apterous. Ovipositor short; apex unarmed, short, hardly separated by small notches. Female genitalia: copulatory papilla very small, broadly quadrangular in dorsal or ventral view, sclerified ventrally and membranous dorsally.

Redescription. Middle-sized, stocky crickets with uniform dull-brown coloration, and dense setation ( Figs 10A , 11A ).

General morphology. Head vertical, but thick ( Fig. 10D ). Eyes small, little protruding. Fastigium ( Fig. 10B, C ) longer than wide, not furrowed; narrowed distally, its base wider than the scapes, its apex narrower that the scapes; separated from the vertex by a very faint transverse furrow; very slightly lower than the vertex in side view; fastigium bearing two close rows of strong setae on midline. Ocelli all large; almost in equilateral triangle. Lateral ocelli at fastigium base, separated from inner margin of eyes by a shallow crest; median ocellus vertical, subapical on fastigium. Vertex flat between the eyes. Maxillary palpi long, even articles 1 and 2 ( Fig. 10B ); article 4 longer than article 3; article 5 the longest, regularly widened toward apex, its apex truncate obliquely, its dorsal margin concave. Scapes longer than wide. Pedicel with a tooth. Pronotum large, wider than long, but not transverse; DD anterior margin concave, posterior margin very slightly bisinuate, almost straight; LL anterior half distinctly raised, its lower margin rounded; LL distal half shorter. Legs I and II thin, legs III distinctly short and thick. Coxae I largely separated. TI shorter than FI; two apical spurs, quite long, the inner longer than the outer by one third of its length; inner and outer tympana both present, small and obliterate, inner tympanum shorter and more rounded, outer tympanum longer and narrower. Coxae II well separated. TII shorter than FII; four apical spurs; inner spurs longer than outer spurs; inner ventral spur the longest and the thickest. FIII distinctly thick, slightly longer than TIII; TIII serrulated between and above subapical spurs, with numerous triangular, thick and flat spines, only TIII base close to the knee without spines; TIII flat between serrulation rows; four pairs of subapical spurs with hook-like apices; inner subapical spurs lower on TIII and shorter than the outers; first inner subapical spur very close to inner apical spurs; three inner and three outer apical spurs, the inners longer than the outers; dorsal inner spur longer than the median, and the longest, about two third basitarsomere III length; median spur the longest on outer side, about half length of inner median spur. Tarsi III about half TIII length; basitarsomere III with two rows on dorsal spines in addition to apical spines, the inner row with fewer spines; inner apical spur of basitarsomere III reaching midlength of distal tarsomere. Abdomen wide and quite flat. Cerci shorter than FIII.

Male. FWs ( Fig. 10C, D ) coriaceous, only partly overlapping; short, not reaching tergite III midlength; without yellow lateral bands. No stridulatory apparatus. Venation made of strong and thick longitudinal veins (two on lateral field, six on dorsal field), separated by numerous, thinner and weaker transverse veins. No glandular structures on metanotum, tergites and supra-anal plate. Subgenital plate short and low, with a short distal furrow. Paraprocts longer dorsally than epiproct, enlarged distally and deeply concave ( Fig. 10F ).

Male genitalia. Fig. 12 . Very flat. Pseudepiphallic sclerite somewhat shorter than the rami, slightly transverse, with convex lateral margins; two short median lobes, raised dorsally at apex with short setae. Rami long, articulated to the pseudepiphallic sclerite on its ventral side. Pseudepiphallic parameres with a thick dorsal sclerite located against the pseudepiphallic sclerite, and a larger ventral sclerite, sinuate basally and subdivided by a deep furrow into an inner part, with a denticulate distal margin, and an outer part, lamella-shaped and slightly concave. Epi-ectophallic invagination well-developped, flat; apodemes shorter than the rami, wide, divergent; arc nearly complete, very narrow. Ectophallic fold elongate, not reaching pseudepiphallic sclerite margin; sclerotized dorsally; apex broadened and truncate; ventral margins slightly sclerotized. Endophallic sclerite reduced to a pair of long and thin plates, on each part of a very thin median sclerite; endophallic apodeme as a thin median longitudinal crest. No dorsal cavity.

Female. Fig. 11A . Distinctly larger than male. Apterous. Epiproct and paraprocts not modified. Subgenital plate short and wide; apex truncate. Ovipositor ( Fig. 11B ) short, compressed laterally; apex short, without ornamentation, hardly separate by a dorsal and a ventral notch.

Female genitalia. Copulatory papilla very small, membranous dorsally, sclerotized ventrally with a distinct quadrangular process ( Fig. 11C–E ).

Habitat. Phaeogryllus fuscus lives on the ground with leaf litter or at the bottom of tree trunks as does Amphiacusta Saussure, 1874 in the Caribbean. It has only been observed in native forest at middle to high altitude.

Figures

FIGURE 10. Phaeogryllus fuscus Bolivar, 1912, male specimen MNHN-EO-ENSIF12265:A, habitus, dorsal view; B, face; C, D, head, pronotum and forewings, dorsal (C) and side (D) views; E, hindfemur; F, terminalia, dorsal view. Abbreviations: epc., epiproct; m.p., maxillary palpus; pc, paraproct; sgen., subgenital plate. Scale bars 1 mm.

FIGURE 11. Phaeogryllus fuscus Bolivar, 1912, female specimen MNHN-EO-ENSIF12266: A, habitus in dorsal view; B, ovipositor, side view; C–E, copulatory papilla in dorsal (C), ventral (D) and side (E) views. Scale bars 2 mm (A, B), 0.1 mm (C–E).

FIGURE 12. Phaeogryllus fuscus Bolivar, 1912. Male genitalia of specimen MNHN-EO-ENSIF12265 in dorsal (A), ventral (B) and side (C) views. Abbreviations see Material and methods.