Eurycorypha willschi, Hemp & Massa & Heller, 2025

Hemp, Claudia, Massa, Bruno & Heller, Klaus-Gerhard, 2025, Description and bioacoustics of three new Eurycorypha (Orthoptera, Tettigonioidea) species from Tanzania and Ghana, with notes on their biology, Journal of Orthoptera Research 34 (2), pp. 187-200 : 187-200

Eurycorypha willschi sp. nov.

Material examined. —

Holotype: IVORY COAST • ♂; Comoé, Zamou ; 10 Nov. 2014; light trap; leg. P. Moretto; MNHN . Paratypes: IVORY COAST • 1 ♂; same locality as holotype; 31 May 2016; light trap; leg. P. Moretto; MNHN • 2 ♂; same locality as holotype; 2 Nov. 2016; light trap; leg. P. Moretto; MNHN .

Additional material examined. —

IVORY COAST • 1 ♀; M’Banto; 6–8 Jul 2013; light trap; leg. P. Moretto; MNHN • 2 ♀; Comoé, Zamou; 2–10 Apr 2016; light trap; leg. P. Moretto; MNHN • 2 ♀; Comoé, Zamou; 19–22 Jun. 2017; light trap; leg. P. Moretto; MNHN • 1 ♀; Boudoukou, Zamou ; Jul 2004; light trap; leg. P. Moretto; MNHN • 2 ♀; Kolomabira; 5 Jun 2016; light trap; leg. P. Moretto; MNHN • 1 ♀; Kolomabira; 2 Nov 2016; light trap; leg. P. Moretto; MNHN • 2 ♀; Mt. Tonkoui ; 20 Jun 2015; light trap; leg. P. Moretto; MNHN • 2 ♀; Mt. Tonkoui ; 17 Oct 2015; light trap; leg. P. Moretto; MNHN • 1 ♀; Mt. Tonkoui ; 11 May 2017; light trap; leg. P. Moretto; BMPC • 1 ♀; Lamto, Toumodi, RBAP Bouhinta ; 26 Jul 1962; MNHN • 1 ♀; Lamto; 15–16 Feb 1969; coll. C. Girard; MNHN • 9 ♂, 4 ♀; Lamto ( Toumodi ); various dates: 20 Mar 1968, 15–30 Oct 1968, 15–21 Jan 1969, 1–12 Nov 1968, 20–30 Jul 1968, 14 Feb 1969, 15–25 Jul 1968, 15–30 Sep 1968, 24–31 Mar 1964, 24–31 Mar 1994, Nov 1966; coll. C. Girard; MNHN . • 1 ♀; Lamto (Toumodi), RBAP, Bauhinia ; 25 Jul. 1952; coll. Paul Planquilte; MNHN . CENTRAL AFRICAN REPUBLIC • 1 ♂; La Maboké; Sep 1963; coll. R. Pujol; MNHN . NIGER • 1 ♂; Haut Niger et Benque ; Ward 159-96; MNHN . BURKINA FASO • 1 ♂; Nazonga, Savane ; 18–25 Oct 1986; coll. N. Berti & Cl. Girard; MNHN . BURKINA FASO (Upper Volta) • 1 ♂; Bobo ; 3 May 1966; coll. Gamontellgrie; MNHN . GUINEA • 1 ♂; Nimba; Dec 1956 – May 1957; leg. Lamotte, Amiet; coll. Vanderplaetsen; MNHN • 1 ♀; Nimba; Feb – Jun 1942; MNHN • 1 ♀; Kindia, Damakanya ; 29–30 Jan 1951; coll. Bechyne; MNHN . BENIN (Dahomey) • 1 ♀; Ouidah ; 1925; coll. Millet-Horsin; MNHN . NIGERIA • 1 ♂; Azare; Oct 1928; coll. Dr. Li Lloyd; NHM . CAMEROON • 1 ♀; Obout; 29 Jul – 12 Aug 2023; coll. A. Willsch . GHANA • 3 ♂, 5 ♀; Larabanga, near Mole National Park ; 16–18 Oct 2022; coll. A. Willsch; CCH .

Description. —

Male. General habitus and color. A medium-sized, elongate species, predominantly green, with a faint pattern of white and yellowish, irregularly distributed veins on the tegmina. The head, pronotum, and body are green with whitish speckles, as observed in life (Fig. 5 A ). When preserved, the white-yellowish pattern fades (Fig. 6 A ). Head and antennae: Antennae typical of Eurycorypha , thin. Fastigium verticis approximately 2.2 times as wide as scapus of antenna; fastigium verticis meeting equally broad fastigium frontis along a well-developed horizontal line; face with evident frontogenal carinae; eyes typical for Eurycorypha , elongate and oval. Thorax: Pronotum with flat and smooth disc, anterior margin of pronotum broadly incurved, posterior margin rounded, lateral carinae evident. Wings: Tegmina elongate, rounded at tips, 3.5–3.8 times longer than broad. Legs. Fore femora dorsally unarmed, ventrally with 3–4 spines. Mid femora with 3 ventral outer spines. Hind femora with 5–7 ventral outer and inner spines. Fore tibiae with an open tympanum on both sides, with a ventral double row of 4–5 spines; mid tibiae with ventral double row of 4–6 spines. Hind tibiae with double row of 18–20 spines at ventral side; 3 slender sclerotized spurs at each side. Abdomen: Last abdominal tergite elongated like a stylus, formed by two parallel running parts; apex separated into two wing-like tips, the lateral sides expanded anteriorly to form two large tightly attached lobes (Fig. 6 B ). From the underside, the two tips are nicely seen with a median oval part formed by the widened ventral margins of the structure that unite further anteriorly (Fig. 6 C ). Cerci broad and laterally compressed with an inner lobe or dent midway; tips of cerci forming two wide lobes; the whole cercus strongly hairy. Subgenital plate of normal shape, broad at base and tapering to its apex; posterior margin broadly incised forming two short lateral processes; without styli (Fig. 6 C ).

Female. — As the male, but with broader tegmina being 3.4–3.5 times longer than broad (Figs 5 B , 7 A ). Ovipositor well-developed and strongly upcurved. The subgenital plate is a triangular flap with an almost rounded posterior margin, only slightly indented in middle. Gonangulum longish, ventrally bulbous. The margins of the lower valves form a thickened ridge within which the ventral bulbous part of the gonangulum is embedded.

Nymphs. — As seen in many Eurycorypha species with known nymphal stages, the first three stages of E. willschi resemble black ants. The nymphs gain more green color while growing and in stage 4 begin to lose their ant-like appearance, changing to leaf camouflage (in Fig. 5 C , three nymphal stages are seen together: L 1, L 2, and L 4). Eggs are oval and black and are laid singly into the margins of leaves (Fig. 5 D ).

Measurements. —

(mm). Males (n = 4). Body length: 18.8–22.1; pronotum length: 4.3–4.8; pronotum depth: 3.9–4.2; length of tegmina: 27.1–28.1; width of tegmina: 7.2–8.0; length of hind femur: 13.5–14.5. Females (n = 8). Body length: 20.3–21.6; pronotum length: 4.3–5.0; pronotum depth: 4.3–4.8; length of tegmina: 29.3–32.1; width of tegmina: 8.4–9.2; length of hind femur: 15.0–16.5; length of ovipositor: 6.0–7.0.

Diagnosis. —

E. willschi , E. stylata Stål, 1873 , and E. stenophthalma Chopard, 1963 are similar, differing in the males in the length of the stylus and the shape of the cerci (see images in OSF). They all have a distinct (but differently shaped) inner cercal tooth, missing in most Eurycorypha species (e. g., in all species known from East Africa). There are also new species belonging to this group of Eurycorypha species with a “ stylus-like ” 10 th abdominal tergite. These species will be treated in a revision of the genus currently in preparation.

The females of E. willschi have widened margins of the ventral valves of the ovipositor that form ear-like structures when viewed from above, as well as having bulbous parts of the ventral gonangulum (Fig. 7 B, C ). Similar to E. willschi are the females of E. stenophthalma known from Chad that also have large bulbs beside the subgenital plate. The female of E. stylata is unknown. The male holotype of E. stylata was collected in Sierra Leone, and there are records also from Senegal ( Hemp and Massa, in prep).

Etymology. —

E. willschi is named after Mr. Achim Willsch, collector of the life specimens of this species in Ghana.

Distribution. —

Widespread in West Africa.

Bioacoustics. —

In the male song, two different elements were observed. At first glance, both are quite similar (see Fig. 8 ), but they differ in SRR and function. Typically, several (to many) similar elements were repeated one after another. One of these elements invariably consists of pairs of syllables (Fig. 9 D ; syllable period 34–38 ms; means of three males, n = 10–18 per male; SRR 26–29 Hz; T = 20–23 ° C). The period of the pairs — called slow echemes — is quite variable (period 4–28 s; means of three males, n = 10–11 per male; range of measurements 2.7–65 s; T = 20–23 ° C). These slow echemes could be heard for relatively long times (up to 10 minutes recorded). More typically, however, a male switched to a series of the other element after a shorter time. This element consisted of 2–3 syllables (Fig. 9 E ; syllable period 20–22 ms; means of three males, n = 18–23 per male; T = 20–23 ° C), thus showing a clearly higher SRR (45–50 Hz); it is therefore called a fast echeme. Most of these series begin with elements of low amplitude and increase then in loudness (Fig. 11 C ).

The females responded exclusively after these fast echemes. Their responses occurred 63–86 ms (means of three females, n = 10–12 per female; T = 20–23 ° C) after the beginning of the last (and loudest) syllable of the male echeme and 99–125 ms after the beginning of the first male syllable. Quite often the male added a series of very short syllables after the female’s response, occasionally even when the female had not answered. See discussion for the function of the parts of the song.

The spectrum of the male song showed a broad peak around 16.5 kHz; that of the female was similar but even broader (Fig. 11 ; see Table 1 for other details). Male stridulatory file, tooth number, and inter-tooth intervals are in the range typical for Eurycorypha (Table 1 ; for comparison, see Heller and Hemp 2020).

Spermatophore. —

During mating, the males transfer a spermatophore to the female as is typical for tettigonioids. At 51.5 mg (10 % male body mass), the size of the spermatophore is typical for the genus (see Table 2 for comparative data mainly based on specimens studied by Heller and Hemp 2020).

Figures

Fig. 5. Eurycorypha willschi. A. Male; B. Female; C. Nymphal stages; D. Eggs.

Fig. 6. Male holotype of Eurycorypha willschi. A. Habitus; B. Lateral view on abdominal apex; C. Subgenital plate.

Fig. 7. Female paraytpye of Eurycorypha willschi. A. Habitus; B. Ovipositor; C. Subgenital plate.

Fig. 8. Oscillograms of male calling songs, overviews (10 s sections). In E. willschi, two slow are followed by one fast echeme.

Fig. 9. Oscillograms of male calling songs and male – female duets, details (1 s sections).

Fig. 11. Power spectra of male calling song of Eurycorypha species. In species with restricted frequency range, short black lines mark its end. Blue lines indicate power spectra of female responses, and the green broken line in E. binasuta indicates the power spectro of the short pulse-like male syllables.