Gryllodes sigillatus (Walker, 1869)

Gryllodes sigillatus (Walker, 1869)

Figs 139 View Figure 139 , 140 View Figure 140 , 141 View Figure 141

References for Socotra.

Taschenberg 1883: 185 [as Cophogryllus sp. ?]; Burr 1898: 385 [as Landreva sp. n.?]; Burr 1903: 412, 422 [as Cophogryllus sp. ?]; Burr 1903: 412, 423 [as Landreva sp. n.?]; Krauss 1907: 30 [as Cophogryllus sp. and Landreva sp. ]; Uvarov (in Uvarov and Popov (1957)): 365 [as Cophogryllus sp. and Landreva sp. ]; Gorochov 1993: 82 [as Gryllodes supplicans ]; Wranik 2003: 316, plates 147, 149 [as Gryllodes supplicans ].

Diagnostic notes.

Gryllodes sigillatus is a typical true cricket with a light brown colour, flattened body and a small head. Males have short, square wings ending halfway to the abdomen (Fig. 139 View Figure 139 ). Females have tiny, reduced scaly wings. The head is light sandy with a broad dark line between the eyes. The pronotum has a characteristic dark hind margin.

Taxonomic notes.

Amongst taxonomists, there is no unanimity about the status of Gryllodes sigillatus and G. supplicans (Walker, 1859) . Otte (2006) considered both as valid species, based on genital morphology. This view is followed by many authors and is accepted by OSF ( Cigliano et al. 2024 a). On the other hand, G. sigillatus is treated as a junior synonym of G. supplicans by Chopard (1967), Kevan and Kevan (1995), Gorochov and Llorente (2001) and Gorochov (2017). Gorochov (1993) mentioned G. supplicans to be present on Socotra. Since we follow OSF, we chose to list the taxon present on Socotra as G. sigillatus .

Taschenberg (1883), Burr (1903), Krauss (1907) and Uvarov (in Uvarov and Popov (1957)) mentioned an unidentified cricket as Cophogryllus sp. , collected by Riebeck in 1881. The museum in Halle ( MLUH) sent a photo of this specimen, which depicts a Gryllodes sigillatus (confirmed by A. Gorochov in litt. 2022, as G. supplicans ).

Burr (1898; 1903), Krauss (1907) and Uvarov (in Uvarov and Popov (1957)) mentioned another unidentified cricket Landreva sp. , collected by Bennet in 1897. Burr (1898) gives a short description, but considers the specimen not good enough for description: “ It is small, testaceous, with truncate tegmina and no wings. The tympanum is only visible on the exterior side of the anterior tibiae (subg. Ectolandreva Sauss.); the posterior tibiae are armed with five spines on each margin above and four terminal spines ”. Based on a photo from the Oxford Museum ( OUMNH), this is also a Gryllodes sigillatus (A. Gorochov in litt. 2022).

Distribution and occurrence.

Gryllodes sigillatus has a worldwide distribution and is widespread on Socotra (Fig. 140 View Figure 140 ).

Habitat and biology.

It is found in various habitats, ranging from sandy plains to shrubland and woodlands and not limited to urbanisation. Nocturnal and hiding by day in all kinds of crevices. Found from 0–1000 m a. s. l.

Bioacoustics.

The calling song of Gryllodes sigillatus is an echeme, lasting about 50 ms and repeated at about 10 per second. Echemes consist of three syllables, the first shorter than the other two. The carrier frequency of the song is around 6.8–7.0 kHz and it has many harmonics at higher frequencies (Fig. 141 View Figure 141 ; https://xeno-canto.org/877942).