Gryllotalpa aff. G. africana Palisot de Beauvois, 1820, 1802

Gryllotalpa aff. G. africana Palisot de Beauvois, 1820 View in CoL

Figs 182 View Figure 182 , 183 View Figure 183 , 184 View Figure 184

References for Socotra.

Uvarov and Popov 1957: 366; Townsend 1983: 183; Wranik 2003: 317, plate 149; Chintauan-Marquier et al. 2016: 58, 67.

Diagnostic notes.

Mole crickets carry a highly distinctive morphology within Orthoptera , including modified forelegs built for digging (Figs 182 View Figure 182 , 183 View Figure 183 ). The specific status of the mole crickets on Socotra is unclear.

We used Townsend’s (1983) key to identify our male specimen collected in 2009 at Ridah, Momi. Most characteristics point to G. africana : the stridulatory teeth of the file are more widely spaced at the centre than at its extremities, the radius is divided distally into two branches and the phallic structure is large (3 mm). Unfortunately, our specimen’s phallic structure is incomplete; only the pseudepiphallus, which is partly damaged, is present (Fig. 183 C View Figure 183 ). It differs from the pseudepiphallus of G. africana , as depicted in Townsend (1983). It also differs from the pseudepiphalli of G. unispina Saussure, 1874 , G. gryllotalpa (Linnaeus, 1758) and G. stepposa Zhantiev, 1991 , as shown in Iorgu et al. (2016), while it is superficially similar to the one of G. krishnani Prassanna 2012 , depicted in Prassanna et al. (2012) and Frank (2020).

Taxonomic notes.

Palisot de Beauvois (1820) described Gryllotalpa africana from several small specimens collected in Oware, a former kingdom bordering Benin ( Palisot de Beauvois 1804).

Townsend (1983) revised the Afrotropical mole crickets and since the syntypes of G. africana were lost, he designated a neotype. He erroneously considered Oware to refer to a river running into Etosha Pan in northern Namibia. The nearest locality from Etosha, where he had specimens suitable as neotypes at his disposal, was South Africa. Therefore, the current G. africana with its neotype from South Africa may belong to a different taxon from Palisot de Beauvois’ original syntypes from Oware ( Benin).

For his revision, Townsend (1983) examined the Socotran Gryllotalpa specimens deposited in the NHMUK and identified them as G. africana . We only found specimens from the Oxford expedition in the London collection, not Popov’s material ( Uvarov and Popov 1957). It is not clear to us which material has been examined by Townsend and if, indeed, he examined the genitalia. Gorochov (1983), in his study on Arabian Grylloidea , examined several specimens of the Gryllotalpa in the collection of NHMUK, but he did not mention any from Socotra.

Since we only have one specimen with an incomplete phallic structure, we tentatively name it Gryllotalpa aff. G. africana , following Uvarov (in Uvarov and Popov (1957)) and Townsend (1983). A thorough study of the genitalia of the London specimens and preferably a new series of Gryllotalpa from Socotra is necessary to properly shed light on this matter.

Distribution and occurrence.

G. africana is found throughout Africa, on the Canary Islands and mentioned for Socotra ( Townsend 1983). Records on Socotra are from several sites across the island, from the lowlands and limestone plateaus to the Hagher (Fig. 184 View Figure 184 ). Most historical records are from Hadiboh and the surrounding plain (Oxford expedition and Popov’s specimens). Some tens of individuals were recorded at night in Feb 2009 at Qeysoh in the west and Momi Plateau in the east. On 30 Oct 2010, individuals were singing deep down the valley from the base camp at Adho Dimello.

Habitat and biology.

Uvarov (in Uvarov and Popov (1957)) mentioned beds of shallow, stagnating, permanent streams overgrown with Juncus and sedges as the primary habitat on Socotra (Fig. 6 View Figure 6 ). In 2009 and 2010, we found Gryllotalpa in wet soils along stagnant waters with Juncus (Zerig) , semi-dry wadis (Momi) and grassy spring areas (Adho Dimello and Qeysoh). On Socotra, Gryllotalpa occurs at a wide elevational range of 60–1000 m a. s. l. The species is attracted to light. Male territories are often easily located due to the loud-calling songs. However, burrows often occur underground from wet riverbanks or submerged in marsh, where they can be difficult to pinpoint.

Bioacoustics.

The song of Gryllotalpa on Socotra is a loud, raucous trill given from a burrow, similar to other species in the genus. The sound is given nocturnally and can be challenging to locate. Unfortunately, we did not make a recording.

Remarks.

Our specimen from Momi has been genetically analysed by Chintauan-Marquier et al. (2016). Sequences are stored in GenBank as G. africana , with voucher numbers KR 903963.1 and KR 903445.1.