Uromenus elegans ( Fischer, 1853 )

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 : 96

Uromenus elegans ( Fischer, 1853)

GREECE: Crete, Lasithi, Kato Zakros, N 35.1, E 026.25, 5 m a.s.l., 15 viii 1991, leg. Heller & Volleth (CH2296; Fig. 4A , Fig 6A ). Crete , Lasithi , 3 km north of Maronia , south of Sitia , N 35.167, E 26.083, 100 m a.s.l., 15 viii 1991, leg. K.-G. Heller ( CH 2897); sound record in Cigliano et al. 2021. Crete , Chania , Chora Sfakion , N 35.201, E 024.143, 100 m a.s.l., 25 v 2016, leg. M. Heller (CH8226–9, 2 males, 2 females, all recorded; Fig. 2 , 4B, C, D ). Crete, Chania, Skaloti, N 35.1969, E 024.2597, 21 v 2018, leg. D. Chobanov ( Fig. 3 ) .

GREECE: Peloponnese, Messinia: Pilos, [N 36.913, E 021.696], 14 vii 87, leg. & recorded F. Willemse (studied by Heller 1988 and figured in Ragge & Reynolds 1998; recording probably overload).

In the field, the songs of all our specimens were recorded in the evening or at night. They consisted of long sequences of syllables (largest recorded duration of a sequence 203 s). The syllables follow each other quite closely ( Fig. 2 , 3 ), but are separated by short intervals during which the tegmina are motionless ( Fig. 4A ). The long syllables are presented in a quite slow rhythm ( SRR 0.5–1.2 Hz) and contain each about 100 impulses ( Tab. 1 ) with the exception of one specimen with shorter syllables (only 41 impulses). This animal, however, has roughly the same high number of stridulatory teeth as one with ‘normal’ song ( Tab. 1 ).

The frequency spectrum of the male calling song has a broad maximum around 15–20 kHz ( Fig. 5 ) or near 30 kHz (another animal).

Males and females produce also sounds when roughly handled or disturbed. These sounds are variable, but contain long series of impulses probably produced during opening and closing of the tegmina ( Fig. 4C, D ) and can in males be similar to syllables of the calling song (compare Fig. 4B and C ).

Compared to the other studied species, the male tegmina are intermediate in size ( Fig. 6A ; from specimen preserved in ethanol) with a relatively small mirror on the right tegmen. The stridulatory file of the male is situated on the underside of the left tegmen and carries about 125 teeth ( Fig. 7 ; Tab. 2 ). In the middle of the file the inter-tooth intervals are about 43 µm. The stridulatory file of the female is situated on the upper side of the concave surface of the right tegmen ( Fig. 8A ). Here the teeth are quite regular ( Fig. 8B ) with inter-tooth intervals about 28 µm in the middle of the file. Other short veins near to the outer edge of the tegmen carry also mostly irregular pegs, but they are certainly not used for sound production. On the left tegmen at the corresponding place a non-functional file (no scraper available) is situated ( Fig. 9A ). On some veins of the upper side of the tegmina, e.g. on those framing the mirror at the posterior edge, the males have also pegs which are similar in size to that of the females (compare Fig. 8B, C ).

Ecology. The species is widespread in Crete with most localities below 450 m a.s.l. ( Willemse & Kruseman 1976). It is found in dry habitats, often on low prickly bushes, as described by Willemse et al. (2018).

Figures

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 4. Oscillograms of sounds of Uromenus elegans from Crete ((A–D) and U. dyrrhachiacus (E). A—Oscillogram of stridulatory movement and song [synchronous registration of left tegmen movement and sound (upper line: upward deflection represents opening, downward closing; lower line: sound)] of two syllables from male calling song (CH2296), B—Single syllable from male calling song (CH8226), C—Male disturbance sound (CH8227), D—Female disturbance sound (CH8229), E Male disturbance sound.

FIGURE 5. Power spectra of the calling songs of the Uromenus species studied here.

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 8. Stridulatory organs and related structures of Uromenus elegans (Crete). A—Female stridulatory file, overview, B—Female stridulatory file, detail, C—Pegs on vein on upper side of right male tegmen. Scale 1 mm.

FIGURE 9. Female tegmina in Uromenus. A—U. elegans (Crete), B—U. dyrrhachiacus, C—U. rugosicollis, D—U. agarenus, E—U. finoti, F—U. tobboganensis and G—U. innocentii. Note the long stridulatory vein on the upper side of the right tegmen crossing the mirror-like translucent tegmen membrane.