Genus Thionia Stål, 1859

Thionia Stål, 1859: 321 . Type species: Issus longipennis Spinola, 1839 .

Diagnosis. Metope wide, almost square, with distinct median and sublateral carinae joined at one point on its upper margin which is straight (Fig. 1). Metope and coryphe joined at obtuse angle (in lateral view) (Fig. 3). Coryphe transverse (Fig. 2). Fore wings long and narrow, rounded apically, far surpassing the apex of abdomen. Forewing vein sequence: R 2–3, with first furcation near to basal cell; M 2, furcating before wing middle; CuΑ 1. Clavus long, open –Pcu+Α1 runs into apex of clavus. Hind wings well developped, 3-lobed. Hindwing vein sequence: R 2, furcating after wing middle; M 1; CuΑ 2, furacting apically; CuP 1; Pcu 2, furcating apically and partly fused with Α1.1 at mid length; Α1 2; Α2 2, furcating at mid length (Fig. 2).

Notes. Thanks to kind help of Dr. Gunvi Lindberg the type specimen of Issus cinctifrons Stål, 1854 is located in the collection of Naturhistoriska Riksmuseet in Stockholm (Sweden). This single male perfectly matching with Stål’s original description of the species (Stål 1854: 247). In particular I. cinctifrons is characterized by wide almost square metope with median carina running from its upper margin to its middle and full sublateral carinae turned to median line above clypeus (Fig. 1). Metope with two rows of yellow spots—traces of larval sensory pits. Fore wings long and narrow, light brown yellowish with green spots besides of claval suture and with longitudinal veins yellow greenish (Figs 2, 3). From other side according to Spinola’s description of Issus rubrocostatus this species is characterized by metope much longer than wide, without carinae—“Front, plus long que large…sans traces de divisions en trois facettes…” and “Base du front…sans arête médiane.” (Spinola 1839: 357). In coloration I. rubrocostatus is distinguished by red longitudinal veins of fore wings—“Nervures principales, rouges…” (Spinola 1839). Thus it is clear that M. Spinola and C. Stål described two different species from Brazil.