Tuarega insignis (Lucas, 1851)

Massa, Bruno, 2013, Pamphagidae (Orthoptera: Caelifera) of North Africa: key to genera and the annotated check-list of species, Zootaxa 3700 (3), pp. 435-475 : 442-443

Tuarega insignis (Lucas, 1851)

Material examined. Tunisia: Ludien 23. IV.1873, 2 ♂; Mamelissa V.1873, 1 ♀ (MSNG); Sidi Mansoun 28. VI.76, 1 ♀ (MSNT); Gabés-Gafsa 1. VI.79, 1 ♀ (BMCP); Bled Segui IV.1884, ♀; Dj. Bou Hedma, ♂ (MNCN); Algeria: Bou Saada 20. IV.77, 1 ♂; Tassili 15. IV.71, 1 ♂ (MZR); Tassili 16. V.72, 1 ♀ (MSNT); Biskra, 3♀; Hoggar, Ehangas 18.V.1951, ♀; Hoggar, Terhenanet, ♀; Beni Abbès 27.III.1952, ♀; Beni Abbès, ♀ paratype of T. sahara ; Morocco: Ouarzazate 25. IV.95, 1 ♂ (BMCP); El Adoua, ♀; Seguiat el Amara, ♂ paratype of T. sahara ; Smara, ♂ paratype of T. sahara ; Rio de Oro, 2♂, 1♀; Morocco, Smara, ♀; Tifariti, 13 ♂, 2♀; Draa, ♀ holotype and ♀ paratype of T. parisi ; Mauritania, Bir Um Grhein, ♀ (MNCN); Libya: Bin Ulid, 1♀; Gheddaia, Bir Seifa, 1♂; Bir Tar, 1♀ (MSNG); Ghadames, 1♀ (MSNT).

Lucas (1851) described Oedipoda insignis from Algerian desert (Kefoum-Tebouc, the ♀ holotype, that should be preserved at MNHN, is not present there and probably it has been lost). According to Kirby (1910), its synonyms are Eremobia jamini Lucas, 1853 (type-locality Biskra, Algeria) and Batrachotettix elephas Saussure, 1884 (type-locality South Africa). Following authors have repeated his opinion. Nevertheless, Saussure (1884) described only the female of B. elephas and from his writing it seems evident that he referred to a species of Pamphagidae with sexual dimorphism (winged male, apterous female); in fact he wrote: “ Elytra et alae? ”; additionally, he described a femur shape (with enlarged upper and lower borders) that is different from that of T. insignis ; thus, seemingly he referred to a species of South African Porthetinae , not a Thrinchinae , subfamily absent South of Sahara . Consequently, this taxon should be removed from the synonyms of T. insignis .

Recently Yin et al. (2011) and Yin & Li (2011) have described other three species from Sahara desert, namely T. ouarzazatensis Yin, Husemann et Li, 2011 ( Morocco), T. parisi Yin et Li, 2011 ( Morocco) and T. sahara Yin et Li, 2011 ( Algeria and Morocco). According to Yin et al. (2011), T. ouarzazatensis differs from T. insignis by the following characters: width of metazona of the pronotum is longer than the length of metazona (in T. insignis it should be shorter), median vein of tegmina is not combined with cubital vein (in T. insignis it is combined at posterior end), and cubital vein of tegmina has two branches (in T. insignis it has three branches). According to Yin & Li (2011), T. parisi differs from T. insignis by the following characters: width of metazona of the pronotum is longer than the length of metazona, median vein of tegmina is not combined with cubital vein, median vein of tegmina has two branches (in T. insignis it has only one branch), and cubital vein of tegmina has two branches; T. sahara differs from T. insignis by the following characters: width of metazona of the pronotum is longer than the length of metazona, median vein of tegmina is not combined with cubital vein, radius vein of tegmina has five branches (in T. insignis and T. parisi it has seven branches), and cubital vein of tegmina has two branches.

Within the series of specimens examined by me, tegmina veins and the number of their branches appeared more or less variable ( Figs. 60–71 ), independently from the geographic area of origin, including also topotypical locality of T. ouarzazatensis . This occurs frequently also in the related genus Tmethis ; these characters indeed are not used to separate taxa in Thrinchinae . Concerning the ratio between the width and the length of metazona, I measured it in 50 specimens of both sexes with characters of T. insignis sensu Yin et al. (2011) , and found in 40 cases a width shorter than length, in 2 cases width and length resulted equal, and in 8 width was longer than length. I carefully examined latter specimens and actually they showed a stout pronotum, clearly laterally enlarged. However, this sometimes occurs in Pamphagidae , mainly in species with dorso-ventrally compressed body, as Tuarega , and also Tmethis , where this ratio is very variable (cf. Figs. 73, 75 and compare them with Fig. 74 ). Within long series of Pamphagidae it is possible to observe single specimens showing stouter and wider body, as previously reported by Uvarov (1943). In addition, Tuarega insignis is a long-winged insect ( Fig. 72 ), that is able to carry very long flights; this consents to cross wide desert areas without being subject to any kind of isolation. In absence of additional elements (e.g., biomolecular analysis), this is a further reason to consider the newly described species of Tuarega from Sahara as synonyms of T. insignis , a species that covers all Sahara desert.

Figures

FIGURES 60 – 75. 60 – 71. Tegmina of Tuarega insignis from different North African localities to show the variability of vein branches, including topotype locality of T. ouarzazatensis (63, 65) and types of T. parisi (68 – 69) and T. sahara (70 – 71). 72. Lateral view of T. insignis. 73 – 75. Tmethis maroccanus and T. cisti from above to show variability of body stoutness.