Phthiarella, 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 : 70-71

Phthiarella gen. nov.

( Figs. 1, 10 )

Type species. Phthia decorata Stål, 1865: 184 .

Description. Head longer than or as long as wide; tylus in lateral view weakly 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 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, finely dentate; humeral angles robust 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 gently convex, smooth; calli rounded, slightly raised, posteriorly with two deep pits, each lateral to midline; triangular process absent; pronotal disk without longitudinal medial carinae; posterior margin with low transverse ridge ( Fig. 1 ); mesosternum with shallow sulcus; metathoracic peritreme bilobate, with two well separated lobes, anterior one longer and semicircular, posterior one shorter and barely rounded; opening obliquely directed. Scutellum wider than long.

Legs. Fore femur with two short and stout subapical spines and 1–2 spines in one row; middle femur with two subapical spines and one row with 3–4 short and stout spines; hind femora ventrally armed with two subapical spines and 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.

Abdomen. Abdominal sterna without medial furrow.

Male genitalia. Posteroventral edge of genital capsule gently sinuate to straight, lateral angles rounded and slightly folded inward ( Fig. 10 ).

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; following areas rather dull: rectangular fascia at anterior lobe of pronotal disk, hemelytra (except punctures), dorsal abdominal segments, rostral segments, pro-, meso- and metasternum, lower margin of acetabulae, coxae, trochanter and abdominal sterna III and IV; antennal segments I–III with or without metallic 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 moderately long, erect setae, segment IV with tiny adpressed setae; legs clothed with large, erect, bristle-like setae.

Differential diagnosis. Phthiarella gen. nov. shares with Phthiadema gen. nov. the following characters: head, abdominal sterna V–VII, male genital capsule and female genital plates entirely metallic green with or without blue and purple iridescence, tylus slightly lower than juga, anterolateral borders of pronotum dentate, pronotal disk without longitudinal medial carinae, and the posttylar depression forming simple sulcus. In Phthiarella gen. nov., the metathoracic peritreme is bilobate (like in Phthia ), and the posteroventral edge of male genital capsule gently sinuate to straight ( Fig. 1 ). In Phthiadema gen. nov. the metathoracic peritreme is simple and the posteroventral edge of male genital capsule has a deep medial notch ( Fig. 6 ).

Phthia is distinguished from Phthiarella gen. nov. by having the dorsal portion of head rather dull, the abdominal sterna V–VII dull and laterally with metallic iridescence, the anterolateral borders of pronotum smooth, the posterior lobe of pronotal disk with low longitudinal medial carinae (sometimes difficult to see) and the posteroventral edge of male genital capsule gently concave, bearing two broad spines on either side ( Fig. 9 ).

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

Distribution. Recorded from Brazil, Ecuador and Peru.

Included species. Phthiarella affinis (Distant, 1901) comb. nov., Ph. decorata ( Stål, 1865) comb. nov., Ph. femorata (Breddin, 1901) comb. nov., and Ph. sponsa (Breddin, 1901) 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.