Ischiodon aegyptius (Wiedemann, 1830)

Mengual, Ximo, 2018, A new species of Ischiodon Sack (Diptera, Syrphidae) from Madagascar, African Invertebrates 59 (1), pp. 55-73 : 56

Ischiodon aegyptius (Wiedemann, 1830) Figure 1

Musca nigra Forsskål, 1775: xxiv. Type-locality: Egypt, Arabia. Type material most likely lost (not found in the digitised type collection of the ZMUC).

Syrphus aegyptius Wiedemann, 1830: 133. Type-locality: Eritrea and Ethiopia, as Abyssinia, here restricted. Lectotype ♂, SMF, here designated.

Syrphus senegalensis Guérin-Méneville, 1832: pl. 99. [Description in 1844: 545]. Type-locality: Senegal.

Sphaerophoria annulipes Macquart, 1842: 103. Type-locality: Egypt.

Syrphus longicornis Macquart, 1842: 154. Type-locality: South Africa.

Syrphus natalensis Macquart, 1846: 262 (134). Type-locality: South Africa, 'Port Natal’.

Syrphus felix Walker, 1852: 229. Type-locality: Canary Is.

Syrphus brachypterus Thomson, 1869: 496. Type-locality: Madeira.

Sphaerophoria pyrrura Bigot, 1884: 99. Type-locality: Senegal.

Sphaerophoria borbonica Bigot, 1884: 100. Type-locality: Réunion Is.

Xanthogramma catalonicum Andreu, 1926: 110. Type-locality: Spain: Prov. Barcelona, Moya.

Differential diagnosis.

Very common species in the Afrotropical region with yellow markings on abdomen reaching the lateral margins (Fig. 1A, C). Males of I. aegyptius have metatrochanters with a long calcar (Fig. 1E) (short calcar in I. scutellaris ) and the claws of the fore leg are asymmetrical (as in Fig. 5F) (males of I. feae also have asymmetrical claws but they do not have a calcar on the metatrochanters). The male genitalia are quite unique with a trilobed surstyli (Fig. 1F). Females are very difficult to distinguish from females of I. scutellaris as the pattern of tergite 2, very often used to distinguish them ( Sack 1932, Huang and Cheng 2012, Speight and Sarthou 2017), is variable. At this moment, conspecific males, DNA barcodes and/or collecting locality may help to distinguish them.

Geographical distribution.

African continent and archipelagos, southern Europe, Israel and Arabian Peninsula.

Type-locality.

Wiedemann (1830) studied an unknown number of specimens from Egypt and Nubia (currently divided into Egypt and Sudan). All the syntypes present in the ZMF collection, collected by Rüppell with original handwritten labels, were collected from Abyssinia, a historical region in northern Ethiopia and southern Eritrea, although sometimes east Sudan is also considered part of this kingdom. Thus, the type-locality is here restricted to Eritrea and Ethiopia based on the lectotype designation.

Material examined.

More than 300 specimens from UAE, Israel, Cyprus, Morocco, Canary Islands, Madagascar, Kenya, The Gambia, Central African Republic, Zimbabwe and South Africa.

Remarks.

Amongst the syntypes, deposited at the Senckenberg Forschungsinstitut und Naturmuseum (SMF, Frankfurt am Main, Germany), there is a pinned male labelled "Abyssinia // Dr.. Rüppell.” “289” [green] "Ischiodon // aegyptius Wd" "Lecto- // Typus" [red] "Dipt. // 300" [reverse] "LECTOTYPE // Ischiodon // aegyptius // det. X. Mengual 2017" [red, second and third lines handwritten]. This specimen is here designated lectotype to fix and ensure the universal and consistent interpretation of the name. The other syntypes, a male and a female without head, have been labelled as paralectotypes: "Abyssinia // Dr.. Rüppell.” "Ischiodon // aegyptius Wd" "Para- // typoid" [red] "Dipt. // 300" [reverse] "PARALECTOTYPE // Ischiodon // aegyptius // det. X. Mengual 2017" [yellow].

Some authors ( Huang et al. 1996, Huang and Cheng 2012) reported specimens identified as I. aegyptius from China, with a complete overlapping distribution inside this country with I. scutellaris (see Huang and Cheng 2012). In the author’s opinion, only I. scutellaris occurs in China and these specimens are misidentifications when the pattern of the tergite 2 is used in females for identification. These works ( Huang et al. 1996, Huang and Cheng 2012) do not specify if there are males of I. aegyptius amongst the studied material, which could be used to corroborate the author’s opinion.