Phthiadema, Brailovsky, 2009

Brailovsky, Harry, 2009, Revision of the Phthia generic complex with a description of four new genera (Hemiptera: Heteroptera: Coreidae: Coreinae: Leptoscelini), Acta Entomologica Musei Nationalis Pragae 49 (1), pp. 59-74 : 68-70

Phthiadema gen. nov.

( Figs. 2, 6 , 14–15, 17 , 20 )

Type species. Leptoscelis cyanea Signoret, 1862: 581 .

Description. Head usually longer than wide; tylus in lateral view slightly lower than juga; posttylar depression forming single sulcus; antennal segment I slightly thicker than following segments, cylindrical, weakly curved outward, thickening gradually from base to apex, longer than head; antennal segments II and III slender, cylindrical, segment IV fusiform; segment IV longest, segment III shortest, segment II longer than I; rostrum reaching posterior third of abdominal sternite III or middle third of sternite IV; rostral segment I at most slightly extending beyond base of head; rostral segment III shortest, segment IV longest, segments I and II subequal.

Thorax. Pronotum wider than long; anterolateral borders obliquely straight, dentate; humeral angles thick at base, tapering into short or large acute to subacute spine, pointing outward; posterolateral borders barely sinuate, outer third dentate, inner third smooth; posterior border straight to weakly concave, smooth ( Fig. 2 ); calli rounded, slightly raised, posteriorly with two deep pits, each lateral to midline; pronotal disk without longitudinal medial carinae; posterior margin with low transverse ridge; mesosternum with shallow sulcus; metathoracic peritreme undivided, simple, not bilobate ( Fig. 17 ); opening obliquely directed. Scutellum wider than long.

Legs. Fore femur with two tiny subapical spines and 1–2 spines in one row (difficult to see); middle femur with two subapical spines and one row with 3–4 short denticles; hind femora ventrally armed with two subdistal spines, two rows of stout and irregular spines, dorsally smooth; hind femur gradually incrassate in both sexes; fore and middle tibiae slender, unarmed, sulcate; hind tibiae ventrally armed with one row of stout and tiny denticles, sulcate, and longer than femur.

Abdomen. Abdominal sterna without medial furrow.

Male genitalia. Posteroventral edge of genital capsule with deep median notch, laterally bearing two short triangular expansions, each lateral to midline, lateral angles rounded, slightly folded inward ( Fig. 6 ). Paramere as in Figs. 14–15 .

Female genitalia. Abdominal sternite VII with fissura short, covering one third of length of sternite; plica subtriangular, apically truncate; gonocoxae I short, subquadrate, medially concave, inner margin open, raised and clearly exposed, upper and outer margins rounded and continuous.

Integument. Body surface shiny, metallic green with blue and purple iridescence; dorsally and ventrally clothed with short, erect, golden to silvery pubescence; pronotal disk, clavus and corium densely punctate; scutellum punctate and transversely striate; pro-, meso- and metacetabulae, propleura and posterior margin of mesopleura and metapleura finely punctate; head, calli, meso- and metapleura, pro-, meso- and metasternum, abdominal sterna, male genital capsule and female genital plates impunctate; antennal segments I–III clothed with short to medium size erect setae, segment IV with tiny adpressed setae; legs clothed with large, erect, bristle-like setae.

Differential diagnosis. Phthiadema gen. nov. can be distinguished from Phthiacnemia gen. nov. by having a shiny, metallic green body surface with blue and purple iridescence, a simple, undivided, not bilobate metathoracic peritreme ( Fig. 17 ), dentate anterolateral borders of the pronotum ( Fig. 2 ), a slightly lower tylus than juga, no longitudinal medial carina on the posterior lobe of pronotal disk, and no medial furrow on the abdominal sterna. In Phthia the body surface is rather dull, sometimes with metallic iridescence restricted to the ventral portion of head, calli, thorax, coxae, abdominal segments III–VI and abdominal sterna III–VII, the metathoracic peritreme is bilobate ( Fig. 16 ), the anterolateral borders of pronotum are smooth ( Fig. 5 ), the tylus slightly higher than juga, the posterior lobe of pronotal disk with a low medial carina (sometimes difficult to see), and the abdominal sterna with a medial furrow.

In Phthiacnemia gen. nov. the entire body surface is rather dull without metallic iridescence, the tylus higher than juga, the posttylar depression absent (present in Phthiadema gen. nov.), the metathoracic peritreme bilobate, and the humeral angles obtuse and truncate (acute to subacute in Phthiadema gen. nov.). Anterolateral borders of the pronotum are dentate in both genera.

Etymology. Named for its similarity to the genus Phthia ; gender feminine.

Distribution. Distributed in the Transandian region of Ecuador, Peru and Bolivia.

Included species. Phthiadema cyanea ( Signoret, 1862) comb. nov., Ph. ornata ( Stål, 1865) comb. nov. and Ph. smaragdina (Walker, 1871) comb. nov.

Figures

Figs. 1–10. 1–5 – pronotum: 1 – Phthiarella decorata (Stål, 1865); 2 – Phthiadema cyanea (Signoret, 1862); 3 – Phthiacnemia picta (Drury, 1770); 4 – Rhytidophthia splendida (Valdéz, 1910); 5 – Phthia lunata (Fabricius, 1787). 6–10 – male genital capsule in caudal view: 6 – Phthiadema cyanea; 7 – Phthiacnemia picta; 8 – Rhytidophthia splendida; 9 – Phthia lunata; 10 – Phthiarella decorata.

Figs. 11–17. 11–15 – paramere: 11–12 – Phthia lunata (Fabricius, 1787), 13 – Phthiacnemia picta (Drury, 1770), 14–15 – Phthiadema cyanea (Signoret, 1862), 16–17 – metathoracic scent gland peritreme: 16 – Phthia lunata, 17 – Phthiadema cyanea.

Fig. 20. Dorsal view of Phthiadema cyanea (Signoret, 1862).