Gryllapterus 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 : 234-238

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https://doi.org/ 10.11646/zootaxa.5047.3.1

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scientific name

Gryllapterus Bolivar, 1912
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Genus Gryllapterus Bolivar, 1912 View in CoL

( Figs. 17 View FIGURE 17 , 18 View FIGURE 18 )

Type species. Gryllapterus tomentosus Bolivar, 1912 View in CoL , by monotypy .

Distribution. Granitic Seychelles islands.

Taxonomic position. Gryllapterus has been described by Bolivar (1912) from one female from the Seychelles within the «tribu des Oecanthiens », close to the genus Landreva Walker, 1869 (as Landrevus ), although Bolivar acknowledged a «relationship» between Gryllapterus and Gryllomorpha Fieber, 1853 (as Gryllomorphus ): «Ce genre a des rapports avec Gryllomorphus , mais je crois devoir le placer à côté du g. Landrevus Walk. dans la tribu des Oecanthiens , parce que les jambes postérieures ont leurs bords et notamment le bord externe denticulés, non seulement la base, mais aussi entre les deux premières épines.» [This genus is related to Gryllomorphus , but I think I have to place it close to g. Landrevus Walk. in the tribe Oecanthiens , because hindleg margins, and in particular the outer margins, are serrulated, not only at base, but also between the first two spines] ( Bolivar 1912, p. 284, our translation).

Saussure (1878) separated the Oecanthiens into three “tribes”, e.g. the Pentacentrites, the Oecanthites and the Phalangopsites, and he classified Gryllapterus within the Pentacentrites together with Landreva . Saussure also recognized that Gryllomorpha , until now classified with Gryllus and related genera, was actually closer to the Phalangopsites, especially to the genus Laranda Walker, 1869 (as Larandus ).

Chopard (1968) gathered Gryllapterus , Landreva and Gryllomorpha , and their respective close relatives, into the Gryllomorphini tribe of the Gryllinae subfamily. Gorochov (1982) created the Landrevinae subfamily for Landreva and its close relatives, later used as a tribe within the Gryllinae by Otte & Alexander (1983). Otte (1988) separated Landreva and Gryllapterus in the Landrevini, which he classified in the subfamily Pteroplistinae explicitly rejecting any close relationship with the Gryllinae and by extension with Gryllomorpha . Gryllapterus was later considered as a Phalangopsinae sensu Eades et al. (2008) ( Hugel 2009) . Finally, Gorochov (2017) proposed that Gryllapterus could belong to the Prolandrevini tribe of the Landrevinae , a subfamily whose affinity with the Gryllinae is now well established ( Chintauan-Marquier et al. 2013, 2016).

Even though the cricket phylogeny obtained by Chintauan-Marquier et al. (2013, 2016) and Warren et al. (2019) included 45 and 65 phalangopsid genera respectively, they take into account only part of the diversity of the whole family, at best one third of present-day genera ( Cigliano et al. 2021). The position of Gryllapterus , close to Gryllomorpha and Petaloptila within the clade ( Homoeogryllini Seselini Hugel & Desutter-Grandcolas n. tribe — Cachoplistini ), is, however, well supported in Warren’s et al. (2019) topology (bootstrap ML support 100, posterior probability of 1 in Bayesian analyses). Morphological characters also confirm the relationships found with molecular data (see below). As a result, we include here Gryllapterus within the Seselini Hugel & Desutter-Grandcolas n. tribe.

Morphological comparison of Gryllapterus , Phalangopsidae , Landrevinae and Gryllinae . The morphology of Gryllapterus resembles that of the phalangopsid species for several characters, two of which could have a particular diagnostic value:

1, hind tibiae serrulated both between and above subapical spurs (not serrulated in Gryllinae ; serrulated only above subapical spurs in true Landrevinae ; Prolandrevini show one or few spines between subapical spurs (not mentioned in Gorochov (2005, 2010), but acknowledged in Gorochov (2011)), which demonstrates that they are not Landrevinae , but Pentacentrinae, to which they should be transferred (S. Hugel, pers. obs., see also Hugel in press),

2, fore tibiae with only two apical spurs (three apical spurs set as a triangle in Gryllinae and Landrevinae ).

In the same way, several characters of male genitalia show that Gryllapterus belongs to phalangopsid crickets:

1, the distal margin of pseudepiphallus bears both a pair of small membranous lobes bearing long setae (median lophi) and a pair of sclerotized hooks directed ventrally (lateral lophi?): these structures are particularly well-developed in Homoeogryllus , Cacoplistes and Meloimorpha . In Landrevinae , the ventro-lateral margin of pseudepiphallus extends distally as a straight processus (see Otte 1988).

2, the endophallic sclerite is flat, connected to an apodeme having the shape of a lamella; it is located close to the base of ectophallic fold, and is not separated from it by a dorsal cavity. In Landrevinae , the endophallic sclerite bears on its anterior part a heavy, “monolithic” apodeme, and is separate from the ectophallic fold by a small, posterior, dorsal cavity; a similar structure exists in the Gryllinae , in which the endophallic sclerite is at the base of a well-developed dorsal cavity.

In Gryllomorpha and Petaloptila , hindtibia serrulation is always present above subapical spurs, but vary between spurs, being either absent, or reduced to one spine between subapical spurs 3 and 4 in examined specimens. Foretibiae always have only two apical spurs however. Their genitalia are very modified, but of a clear phalangopsid type in at least some species, such as Petaloptila pallidens Bolivar, 1927 .

It is not the scope of the present paper to assemble a matrix of morphological characters to complete molecular phylogenetic analysis. However, morphological and molecular data show that Gryllapterus should be removed from the gryllid subfamily Landrevinae to be classified within the phalangopsid subfamily Cachoplistinae .

Diagnosis. Very small specimens with contrasted coloration and short legs ( Figs 17A View FIGURE 17 , 18A View FIGURE 18 ). Eyes little protruding, longer than wide, well-separated from the cheek posterior margin. Fastigium triangular, very wide at base, not separate from the vertex by a distinct furrow; with very thick setae; ocelli small and rounded, set as a wide triangle ( Fig. 17E View FIGURE 17 ). Fore tibiae with two ventral apical spurs; with a small inner tympanum. Mid tibiae with three apical spurs. Hind femora very wide; hind tibiae with four pairs of subapical spurs; serrulated between and above spurs.

Male. Forewings short, not reaching tergite 2 distal margin ( Fig. 17B, C View FIGURE 17 ), slightly overlapping, without stridulatory or glandular structure; with strong longitudinal veins, and a wide, white band along lateral margins. Metanotum glandular ( Fig. 17D View FIGURE 17 ). Male genitalia ( Fig. 17G–J View FIGURE 17 ): pseudepiphallic sclerite short, transverse, widely separated from distal median lophi; these lobes short and acute; latero-ventral sclerotization of pseudepiphallus (lateral lophi?) produced as a pair of wide hooks directed ventrally; pseudepiphallic parameres with a large dorsal sclerite and a smaller, bifid ventral sclerite; ectophallic apodemes thick, divergent; no endophallic cavity. Female. Apterous ( Fig. 18A View FIGURE 18 ). Ovipositor flattened laterally; regularly narrowed toward apex; apex hardly separated and not ornamented ( Fig. 18B View FIGURE 18 ). Female genitalia: copulatory papilla small; rectangular, widely sclerotized ( Fig.18C–E View FIGURE 18 ).

Redescription. Very small specimens with contrasted coloration ( Figs 17A View FIGURE 17 , 18A View FIGURE 18 ).

General morphology. Head slightly longer than wide in front view, thick in side view. Eyes somewhat protruding, longer than wide, well-separated from the posterior margin of the cheeks. Head dorsum flat, separated between the eyes from the fastigium by a very faint convex furrow. Fastigium ( Fig. 17E View FIGURE 17 ) triangular, very wide basally, regularly narrowed toward apex; apical width about half basal width; apex about as wide as the scape; not furrowed; with strong setae dorsally. Ocelli small but well-visible, rounded; set as a wide triangle, the distance between the lateral ocelli slightly greater than the distance between the median and one lateral ocelli; median ocellus vertical, far from fastigium apex. Scapes slightly longer than wide, rounded. Maxillary palpi ( Fig. 17C View FIGURE 17 ) short; article 3 shorter than article 4; article 4 shorter than article 5; article 5 regularly widened toward apex from its base, concave dorsally; apex convex. Pronotum ( Fig. 17B View FIGURE 17 ) transverse; DD anterior and posterior margins slightly convex and concave respectively, with lateral margins distinctly rounded; LL short, with sinuate lower margin, distinctly raised anteriorly ( Fig. 17C View FIGURE 17 ). TI with a short, oval inner tympanum; no outer tympanum; two long, apical ventral spurs; no dorsal spurs. TII with three long apical spurs, the ventral the longest; dorsal outer spur missing. FIII very wide ( Fig. 17F View FIGURE 17 ), longer than TIII. TIII slightly furrowed dorsally except near base and apex; serrulated on inner and outer ridges, between and above subapical spurs; with four inner and four outer subapical spurs, short and subequal in size, the outers slightly located more basally; with three inner and three outer apical spurs; dorsal inner spur the longest, slightly longer than median inner spur, both about two third basitarsomere III length, flat on inner side and quite wide; median outer apical spur the longest, more than twice as long as dorsal outer spur; inner and outer ventral spurs short and thin, the inner slightly longer than the outer and about one third the median inner spur. Basitarsomeres III with outer spines, growing bigger toward apex; apical spine only on inner side. Cerci shorter than FIII.

Male. FWs very short, not reaching abdominal tergite 2 midline ( Fig. 17B View FIGURE 17 ); overlapping in their midline only; without a stridulatory design. Dorsal field with 5 longitudinal veins, the two most lateral largely separated and ivory coloured ( Fig. 17C View FIGURE 17 ); few transverse veins. Lateral field with two longitudinal veins, in addition to the thick vein separating the dorsal and the lateral fields. Metanotum glandular (17D): in anterior part, a wide, setose depression; in posterior part, a strong median relief with two lateral crests, bordered on each side by a wide setose area, and connected to the inflated posterior margin of metanotum bearing a pair of lateral reliefs separated by a median depression. Abdomen without glandular structures. Subgenital plate short and flat.

Male genitalia. Fig. 17G–J View FIGURE 17 . Flat and ovoid. Distal margin of pseudepiphallic sclerite deeply indented, with a pair of very small apical lobes (median lophi) located on the distal angle of the emargination and directed anteriorly. Latero-distal margin produced ventro-posteriorly into a pair of sclerotized hooks (lateral lophi?), thick at base but abruptly thinner before apex, making an angle <90 with pseudepiphallic sclerite. Rami thick, convex; distal apex bifid, the dorsal branch extremely reduced. Pseudepiphallic parameres with two large sclerites, one undivided, dorsal, concave, and one ventral, bifid as a broad forceps. Ectophallic apodemes long and straight, regularly diverging from the arc. Ectophallic arc very wide, convex dorsally at midwidth. Ectophallic fold membranous dorsally, exceeding pseudepiphallic distal margin, truncated apically. Endophallic sclerite long and narrow, wide and less sclerotized laterally. Endophallic apodeme with a short, distal median crest. No endophallic cavity.

Female. Fig. 18A View FIGURE 18 . Apterous. Subgenital plate transverse; distal margin indented. Ovipositor compressed laterally, regularly narrowed toward its tip, only a small depression delimiting the apex; apex acute, without ornementation ( Fig. 18B View FIGURE 18 ).

Female genitalia. Copulatory papilla ( Fig. 18C–E View FIGURE 18 ) short, very flat and almost rectangular; distal margin bisinuate; papilla largely sclerotized and somewhat concave ventrally.

Habitat. Native forests above 500 m ( Matyot 1998).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Orthoptera

Family

Gryllidae

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