Eurycorypha spicula, 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 spicula sp. nov.

Material examined. —

Holotype: TANZANIA • ♂; Nguru Mts; 1900 m a. s. l.; montane forest above Dibago / Maskati ; November 2021; CCH . Paratypes: • 11 ♂, 11 ♀; same data as holotype; CCH .

Description. —

Male. Habitus and color. A roundish medium-sized species, green with lighter veins on the tegmina and speckled with white dots and patches on pronotum and head (Fig. 2 A ). Color pattern white to yellowish veins on dark green background on the tegmina, rest of body also speckled yellowish-green. Head and antennae: Antennae typical of Eurycorypha , thin, about as long as flexed tegmina. Fastigium verticis about 2.4 times as wide as scapus of antenna; fastigium verticis meeting equally broad fastigium frontis along a well-developed horizontal line; face with callose frontogenal carinae, yellow when alive; eyes typical for Eurycorypha , elongate and oval. When alive, with yellow fasciae. Thorax: Pronotum with flat and smooth disc, anterior margin of pronotum broadly incurved, posterior margin broadly rounded. Wings: Tegmina roundish, only about 2.5 times longer than broad; alae only slightly protruding. Stridulatory file comparatively long, evenly curved, and about 2.2 mm long, consisting of very densely packed teeth. Legs: Fore coxa with very short, broad-based spine. Fore and mid femora dorsally unarmed, ventrally with 2–4 spines on outer side and without inner spines. Hind femora ventrally with 4 spines at apical end. Fore and mid tibiae with ventral double row of few spines (3–8). Hind tibiae with 4 rows of spines and three spurs at each side. Abdomen: Last abdominal tergite with two broad-based short spines at posterior margin (Fig. 3 A ). Cerci thick at base, narrowing to their apices and ending in a sclerotized small ridge (Fig. 3 A, C, E ). Subgenital plate with broad base. Posterior margin incised forming two short processes with small styli (Fig. 3 C ).

Female. — Very roundish and compact, of same color pattern as male (Fig. 1 B ). Ovipositor well-developed, upcurved (Fig. 3 B ). Subgenital plate forming a triangular flap. Lateral margins of the lower valves are thickened, running in parallel to the subgenital plate and forming an ear-like grove or hole lateral at base of pronotum (Fig. 3 B, D, F ).

Nymphs. — The first stages resemble black ants, gaining more color in stages two and three (Fig. 2 C, E ). Unlike most other Eurycorypha species where nymphal stages are known, the nymphs of E. spicula are dorsally black on the head, the pronotum, and the abdomen, and the legs are partly black. The black coloration persists in the last two stages four and five (Fig. 2 F ) and vanishes when molting to the adult, which is predominantly green (Fig. 2 A, B ). Eight nymphs (L 1 – L 3) were collected in November 2024 at the same locality as in 2021, suggesting that this species hatches in November, coinciding with the onset of the short rains and rising temperatures.

Biology. —

L 1 and L 2 nymphs were collected in November 2021 from a flowering Bidens kilimanjari at an elevation of about 1900 m a. s. l. in the Nguru Mountains above Dibago / Maskati. They were taken to the laboratory and reared to adults on various leaves from trees and bushes at Mt Kilimanjaro. The first adults emerged on the 12 th of January 2022. Thus, as in most other Eurycorypha where development time from hatching to the adults is known, E. spicula takes about 2 months from hatching to the adult.

Some specimens were infected by Nematoida while reared in the lab. Fig. 4 shows a nematoid approximately 10 times the length of the insect that emerged from an adult female of E. spicula .

Measurements. —

(mm). Males (n = 13). Total length: 27.2–32.6; body length: 12.7–19.3; pronotum length: 4.1–4.6; pronotum depth: 3.1–3.5; length of tegmina: 20.8–27.1; width of tegmina: 9.2–10.6; length of hind femur: 13.4–15.2. Females (n = 9). Total length: 27.1–28.7; body length: 15.7–16.9; pronotum length: 4.2–4.8; pronotum depth: 3.2–3.7; length of tegmina: 22.7–24.6; width of tegmina: 9.5–11.5; length of hind femora: 13.9–16.6; ovipositor: 5.5–5.6.

Diagnosis. —

Males of E. spicula are somewhat roundish but less so than in the closely related E. paraspicula . They are distinguished by the presence of two relatively short spines at the posterior margin of the tenth abdominal tergite, and slender, tapering cerci with narrow tips that end in a small sclerotized point. Although morphologically very similar to E. paraspicula , the male of E. spicula can be differentiated by its more elongated appearance and less robust cerci. The female is known and displays a compact, roundish habitus, a well-developed upcurved ovipositor, and a triangular subgenital plate bordered by thickened ridges.

Bioacoustics. —

The male song consists of complicated and quite characteristic echemes. One relatively long syllable is followed by a series of shorter elements (Figs 8 B , 9 B ). Surprisingly, some parameters of these echemes were quite variable in the three recorded males. The duration of the long syllables varied between 38.4 and 84.4 ms, the number of short syllables ranged between 6.8 and 11.8, and variation of the duration of the complete echeme was also not small (324–441 ms; all means of 3 males; n = 10 per male; T = 21 ° C). More constant were the periods between the beginning of the long syllable and that of the series of short syllables (138–152 ms) and between the short syllables (28.5–31 ms corresponding to 32–35 Hz SRR; measured from the beginning of the 5 th to that of the 6 th syllable). The echemes were repeated at intervals of several seconds. When two males were singing in acoustical contact, the structure of their echemes became more irregular (‘ leader’ in Fig. 10 A, B ; upper line), while the other (‘ follower’ in Fig. 10 ; lower line) placed his echemes immediately after that of the first. Occasionally the leader also produced long series of short syllables.

The first answer of females was recorded approximately 417 ± 27 ms (mean ± SD; n = 10) after the beginning of the echeme, 281 ± 27 ms after the beginning of the syllable series, and 76.5 ± 30 ms after the end. However, in other situations (e. g., when several males were singing), the females responded more variable with latencies of the first response very close to the end of the male echeme (0.6 ± 50.1 ms – 2.6 ± 35.6 ms). The amplitude modulation of their response was also very variable, from single impulses (Fig. 9 B ) to series of impulses, probably produced by repeated tegmen movements (Fig. 9 C ). If they were not answers to their own songs, males reacted to these sounds, sometimes by producing a series of short syllables (Fig. 9 C ). See the discussion for the function of the parts of the song.

The spectrum of the male song showed a broad peak around 13 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).

Figures

Fig. 1. Eurycorypha paraspicula. A, B. Male; C. Lateral view of male abdominal apex of alive specimen; D. Dorsal view of male abdominal apex; E. Ventral view of male abdominal apex with subgenital plate.

Fig. 2. Eurycorypha spicula. A. Male; B. Female; C. Second instar; D. Molting from L 1 to L 2; E. Third instar; F. Fourth instar.

Fig. 3. Eurycorypha spicula. A. Semi-dorsal view of male abdominal apex; B. Lateral view of ovipositor; C. Semilateral view of male subgenital plate; D. Subgenital plate of female; E. Semilateral view of male abdominal apex of alive specimen; F. Subgenital plate of alive female specimen.

Fig. 4. Nematomorpha parasite emerging from adult female of Eurycorypha spicula.

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. 10. Oscillograms of male – male interactions (A, B. Upper line leader, lower line follower; blue) and male – female duets (C. Five slow echemes followed by a series of fast echemes).

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.