Thabena Stål, 1866

Gnezdilov, Vladimir M., 2009, Revisionary notes on some tropical Issidae and Nogodinidae (Hemiptera: Fulgoroidea), Acta Entomologica Musei Nationalis Pragae 49 (1), pp. 75-92 : 77-78

Genus Thabena Stål, 1866

Thabena Stål, 1866a: 208 . Type species: Issus retractus Walker, 1857 , by subsequent designation ( STÅL 1866b: 393).

Cibyra Stål, 1861: 209 (preoccupied). Type species: Issus testudinarius Stål, 1854 (= Issus spectans Walker, 1858 ), by original designation.

Gelastyra Kirkaldy, 1904: 280 , syn. nov. New name for Cibyra Stål, 1861 .

Gelastyrella Yang, 1994 in CHAN & YANG (1994): 90, syn. nov. Type species: Gelastyrella litaoensis Yang, 1994 in CHAN & YANG (1994), by original designation.

Borbonissus Bonfils, Attié & Reynaud, 2001: 217 , syn. nov. Type species: Borbonissus brunnifrons Bonfils, Attié & Reynaud, 2001 , by original designation.

Redescription. Body wide in dorsal view ( Fig. 1 ). Metope wide, weakly enlarged towards clypeus, with median keel crossed by transverse keel below upper margin ( Fig. 3 ). Coryphe transverse, with keeled margins, anterior margin convex or obtusely angulate, posterior margin concave ( Fig. 4 ). Pronotum and scutellum without keels. Fore wings narrowing apically, without hypocostal plate, clavus with cuspidal caudo-dorsal angle ( Fig. 2 ). Radius bifurcate, median tri- or tetrafurcate, cubitus anterior simple or bifurcate (vein formula R 2 M 3–4 CuA 1–2). Hind wings almost equal in length to fore wings, bilobed, with well-developed remigium and vannus, separated by deep cleft, with many transverse veins, costal margin concave, anal lobe of vannus rudimentary. Hind tibia with two lateral spines distally. First metatarsomere apically with 8–33 intermediate spines arranged in several rows. Female sternum VII with large median process on posterior margin.

Differential diagnosis. Thabena is distinguished within the Issini by the combination of the following characters: metope wide with median keel crossed by transverse keel inferior to its upper margin; clavus of fore wing with cuspidal caudo-dorsal angle; hind wing bilobed with well-developed remigium and vannus, separated by deep cleft, with many transverse veins, and rudimentary anal lobe of vannus.

Comments. Examination of the type species of the genera Thabena Stål, 1866 and Gelastyra Kirkaldy, 1904 has revealed that both species are congeneric. The genus Gelastyrella erected by Yang (in CHAN & YANG 1994) differs from Thabena Stål (= Gelastyra Kirkaldy ) in the large number of intermediate spines on the first metatarsomere, but other external morphological features, such as the shape of and keels on the metope, the shape and venation of fore and hind wings, and the structure of male genitalia, suggest that Gelastyrella species can be accommodated under Thabena as well. However, Issus patulus Walker, 1857 (= Issus sobrinus Walker, 1857 ), which has been treated as belonging to Thabena ( METCALF 1958, LIANG 2001), differs from other Thabena species in having a narrow metope, elongate coryphe, trilobed hind wings (with well-developed anal lobe of vannus) and different structure of the male genitalia, and should be included in a distinct genus (GNEZDILOV, in prep.).

The genus Borbonissus Bonfils, Attié & Reynaud, 2001 , erected for two species from Réunion Island ( BONFILS et al. 2001), is a polyphyletic group. The type species of the genus, Borbonissus brunnifrons Bonfils, Attié & Reynaud, 2001 , belongs to Thabena based on the characters listed in the generic diagnosis above. The other species, Borbonissus vayssieresi Bonfils, Attié & Reynaud, 2001 , is not related to B. brunnifrons and should be included in a separate genus, Euroxenus gen. nov., which is probably closely related to the Oriental Eusarima Yang, 1994 in CHAN & YANG (1994).

Thabena thus now includes 13 species distributed in continental China, Indonesia, Malaysia, Philippines, Singapore, Taiwan, Thailand and Réunion Island. The centre of speciation and apparently the centre of origin of this genus are probably situated in Southeastern Asia, where nine species are distributed. Thabena brunnifrons ( Bonfils, Attié & Reynaud, 2001) , comb. nov., is the only species of Thabena known from outside the Oriental Region. Besides Réunion Island, it is newly recorded here also from Singapore.

Figures

Figs. 1–6. 1–4 – Thabena retracta (Walker, 1857), specimens from Sarawak: 1 –J, holotype, dorsal view; 2 – same, lateral view; 3 – same, face; 4 –♀, head, dorsal view. 5–6 – Gergithoides carinatifrons Schumacher, 1915, specimens from Taiwan: 5 – J, dorsal view; 6 – ♀, frontal view.