Uromenus robustus ( Werner, 1933 )

Heller, Klaus-Gerhard, Puskás, Gellért, Szövényi, Gergely & Chobanov, Dragan P., 2021, Songs in the genus Uromenus (Orthoptera: Tettigoniidae: Ephippigerini): A review with new information about some species, Zootaxa 4991 (1), pp. 93-115 : 103

Uromenus robustus ( Werner, 1933)

MOROCCO, Ouaouizeght , N 32.13725, W 006.33720, 900 m a.s.l., 09 vi 2013, leg. Chobanov.

The nightly calling song consists of echemes with 7.7±1.6 (n=6) syllables ( Fig. 2 ; syllable period 660±52 ms; SRR 1.5 Hz). In these syllables, a short opening hemisyllable (65±7 ms) is followed by a longer closing hemisyllable (267±8 ms) containing 64±3 (n=6) impulses ( Fig. 3 ), both having approximately the same amplitude.

The frequency spectrum of the male song has a relatively low maximum around 10 kHz.

The male tegmina ( Fig. 6D ) are the largest of all species studied here. Interestingly, the non-functional file on the lower side of the right tegmen can be recognised from above. The male stridulatory file carries about 110 teeth ( Fig. 7 ; Tab. 2 ). In the middle of the file the teeth are widely spaced with inter-tooth intervals of about 83 µm.

Morphology. This species has been grouped together with U. maroccanus ( Saussure, 1898) , U. vaucherianus ( Saussure, 1898) , U. hastatus ( Saussure, 1898) , U. chamaeropis Werner, 1931 , and U. galvagnii Nadig, 1994 , into the Robustus Subgroup. The taxa within this group are distinguished based on the shape of the genital appendages. Females of the Robustus Subgroup differ from the Finoti Subgroup by the distal protuberances of the lower ovipositor valve pointing downwards or being only slightly outcurved; the copulatory area being at the lower edge of the eighth tergite, funnel-shaped. Male 10th tergum, epiproct, cerci and titillators are shown on Fig. 10C 1–2 and Fig. 11D . The studied specimens of this species were distinctly more robust and larger than the other taxa here reported.

Ecology. Our observation of the species is from a very dry partly ruderalized habitat dominated by bare soil with rare thistles, thorny bushes and palms ( Fig. 1L ). Though the locality generally fits the distribution of the Hot-summer Mediterranean climate in Morocco ( Verner et al. 2018), it falls under the climate shadow of the surrounding mountains and thus may classify within the Köppen climate type BSh (Hot semi-arid) .

Figures

FIGURE 1. General appearance and habitats of Uromenus species. A—U. elegans (Italy, Lazio), B–D—U. elegans (Crete; photos B and C taken by Ionuţ Iorgu), E, F—U. dyrrhachiacus, G—U. agarenus, H–J—U. finoti, K, L—U. robustus, M, N—U. tobboganensis, O—U. maroccanus, P, Q—U. melillae, R—U. innocentii, S, T—U. choumarae.

FIGURE 2. Oscillograms of male calling songs of the Uromenus species studied here, 10 second sections.

FIGURE 3. Oscillograms of male calling songs of Uromenus species studied here, 2 second sections.

FIGURE 6. Male tegmina in Uromenus. A—U. elegans (Crete), B—U. dyrrhachiacus, C—U. finoti, D—U. galvagnii, E—U. robustus, F—U. tobboganensis and G—U. innocentii.

FIGURE 7. Male stridulatory files in Uromenus. A—U. elegans (Crete), B—U. dyrrhachiacus, C—U. finoti, D—U. galvagnii, E—U. robustus, F—U. tobboganensis, G—U. melillae, H—U. innocentii, I—U. choumarae.

FIGURE 10. Cerci of the Moroccan species of Uromenus studied here and of U. dyrrhachiacus. A—U. finoti, B—U. galvagnii, C—U. robustus, D—U. tobboganensis, E—U. melillae, F—U. innocentii, G—U. choumarae, H—U. dyrrhachiacus

FIGURE 11. Titillators of U. dyrrhachiacus and of the Moroccan species of Uromenus studied here. A—U. dyrrhachiacus, B—U. finoti, C—U. galvagnii, D—U. robustus, E—U. tobboganensis, F—U. melillae, G—U. innocentii, H—U. choumarae. Scale 2 mm except for U. dyrrhachiacus - 0.9 mm.