Dithela longicaudata, Massa, 2017

Massa, Bruno, 2017, New genera, species and records of Afrotropical Phaneropterinae (Orthoptera, Tettigoniidae) preserved at the Royal Belgian Institute of Natural Sciences, Bruxelles, Zootaxa 4358 (3), pp. 401-429 : 403-405

Dithela longicaudata n. sp.

Figs 2A–2H

Material examined and depository. Democratic Republic of Congo, Kalulu 6.V.1939, H.J. Brédo (♂ holotype, 1♂ paratype, without hind legs) ( RBINS).

Other material examined. Dithela rectiloba Karsch, 1890 . Cameroon, Barombi Station, Preuss (♂ holotype) ( MfN); Equatorial Guinea, Fernando Poo (1♂, 1♀) ( MNCN); Dithela acuticercus Sjöstedt, 1912 . Cameroon, Victoria (1♂) ( MfN).

Measurements. Males. Body length: 15.2–15.7; length of pronotum: 2.7–2.9; height of pronotum: 2.1–2.3; length hind femur: 19.2; length of hind tibia: 20.0; length of tegmina: 19.7–21.0; width of tegmina: 3.7–4.2.

Diagnosis. It is an atypical Dithela , characterized by the presence of 1 spur on the dorsal fore tibiae, 2 spurs on dorsal mid tibiae, tegmina clearly shorter than hind wings, cerci pointed and up-curved, subgenital plate long, narrow with two parallel lobes, apically divergent.

Description of the male ( Fig. 2A ). Colour. Green with yellowish-green legs, antennae brown, stridulatory area of the left tegmen a little darkened. Head. Fastigium of vertex very narrow, sulcate above, separated from the fastigium of frons, which is tuberculated. Eyes rounded, well projecting, 2 times as smaller than subocular groove. Pronotum. Lobes very low and humeral sinus barely marked, anterior margin of pronotum straight, posterior rounded. Legs. Fore coxae unarmed. Fore tibiae furrowed superiorly, distinctly widening above tympanum. Tympanum open on inner and outer sides. Fore femora armed with 4–7 spines on ventral inner and 3–6 on ventral outer margins, fore tibiae with 6 spines + 1 spur on ventral inner and outer margins, and 2 spines + 1 spur on dorsal outer margin. Mid femora with 6–9 spines on ventral outer margin, mid tibiae with 8 spines + 1 spur on ventral inner and outer margins and 5–6 spines + 1 spur on dorsal inner and outer margins. Hind femora unarmed, hind tibiae with 5–6 spines on ventral inner margin and ca. 40 spines on dorsal inner and outer margins + 3 spurs on each side. Wings. Tegmina narrow. Stridulatory area of the left tegmen stout and long, mirror of the right tegmen wide. Stridulatory file short, ca. 1.2 mm long, consisting of less than 40 unevenly distributed teeth ( Fig. 2B ). Abdomen. 10th tergite unmodified, with a straight hind margin. Cerci long, pointed and up-curved ( Fig. 2D ), shorter than the subgenital plate. Subgenital plate long and narrow with two parallel lobes, apically divergent, styli absent ( Figs 2F, 2G ).

Female: unknown.

Affinities. D. longicaudata n. sp. differs clearly from the two known species of Dithela by the characters reported in the discussion of the genus. Only D. acuticercus ( Fig. 2C ) is vaguely similar to D. longicaudata n. sp., but it differs by the shape of wings and of the subgenital plate and cerci ( Figs 2E, 2H ).

Etymology. From Latin = with long tail.

Distribution. Actually known only from the Democratic Republic of Congo.

Figures

FIGURE 2. Dithela longicaudata n. sp. and Dithela acuticercus SjÖStedt, 1912. A) Lateral view of D. longicaudata n. sp. B) Stridulatory file of D. longicaudata n. sp. C) Lateral view of D. acuticercus. D) Lateral view of laSt abdominal SegmentS and cerci of D. longicaudata n. sp. E) Lateral view of laSt abdominal SegmentS and cerci of D. acuticercus. F) ventral view of the Subgenital plate of D. longicaudata n. sp. G) DorSal view of cerci and Subgenital plate of D. longicaudata n. sp. H) DorSal view of cerci and Subgenital plate of D.acuticercus.