Thyanta (Argosoma) infuscata Rider, 1991

Thyanta (Argosoma) infuscata Rider , new species

Figs. 337-351, Map 2

Description. Dorsal surface pale green; posterior third of pronotum dark green, margin between pale and dark areas irregular; medial longitudinal band on scutellum yellowish-green; punctures reddish-brown.

Apex ofhead broadly rounded; outer jugal margins nearly parallel for middle third of distance from eyes to apex ( Fig. 338). Antennae pale reddish-brown, distal two and one-half segments darker. Anterolateral margins of pronotum weakly concave in dorsal view; humeral angles narrowly rounded, almost angulate, produced beyond margin of adjacent coria by about one-half width of eye, piceous apically ( Fig. 337). Mesia! margin of each pronotal cicatrice marked with fuscous or piceous, sometimes only vaguely so. Punctures on pronotum crowded anterior to cicatrices, sparse along anterolateral margins. Hemelytra uniformly and shallowly punctate, punctures slightly more dense on exocorium than corium; posterior margins nearly straight; posterolateral angles narrowly rounded, extending nearly to posterior margin of penultimate connexival segments. Hemelytral membranes hyaline with numerous brown flecks; inner basal angle distinctly infuscated ( Fig. 337). Connexiva pale green; posterolateral angles piceous.

Ventral surface yellowish-green; punctures concolorous to reddish-brown. Rostrum pale yellowish brown, apical half of segment 4 black, reaching onto base of third (second visible) abdominal sternite. Ostiolar canals acuminate apically. Femora and tibiae pale yellowish-green; vague brown spot present on superior surface of each femur at distal third. Postspiracular black spots absent. Posterolateral angles of abdominal sternites piceous.

Mesial margins of basal plates in caudoventral view slightly convex, separated basally; posterior margins slightly concave; posteromesial angles slightly emarginate, fuscous ( Fig. 349). Sclerotized rod swollen subapically, abruptly narrowed apically ( Fig. 350); spermathecal duct moderately swollen below proximal flange, length of duct from proximal flange to sclerotized rod short relative to congenors ( Fig. 351). Posterior margin of pygophore broadly and sinuously U-shaped in caudal view, medial portion slightly sinuous ( Fig. 345); posteroventral surface only weakly produced into blunt, chin-like protuberance, surface between protuberance and posterior margin appearing only slightly depressed in lateral view ( Fig. 348); posterior margin slightly concave in ventral and dorsal views ( Figs. 346, 347). Apex of each paramere narrowly rounded in medial view, apex bent dorsad ( Fig. 339); narrowly rounded in ectal view ( Fig. 341); roughened, spiculate area on lateral surface ovoid, localized ( Fig. 340). Aedeagus with conjunctiva! lobes large, each lateral lobe with 2 obtuse diverticula ( Fig. 344); median penial lobes and penisfilum relatively small, obscured by conjunctiva! lobes ( Fig. 342); dorsomedial conjunctiva! lobe relatively large ( Fig. 343).

Measurements. Total length 7.41-9.46 (7.41); total width 5.20-5.83 (5.20); medial length of pronotum l.66-1.88 (l.66). Medial length of scutellum 3.39-3.90 (3.39); basal width 3.31-3.68 (3.31); width at distal end of frena 1.10-1.40 (1.10). Length ofhead 1.46-1.64 (1.46); width 2.08-2.21 (2.08). Length of segments 1 -5 of antennae 0.39--0.44 (0.39), 0.77--0.88 (0.77), 1.03-1.10 (1.03), 1.10-1.29 (1.10), and 1.10- 1.21 (1.10), respectively. Length of segments 2-4 of rostrum 1.23-1.29 (1.23), 0.74--0.77 (0.77), and 0.74--0.75 (0.75), respectively.

Holotype. -3 labeled " ECUADOR: Pichincha Prov. Tinalandia; 12 km E Sto. Domingo de los Colorados . ca. 2,500 ft, 11-17-V-1986. J. E. Eger, coll." Deposited in the Florida State Collection of Arthropods (Gainesville) .

Paratype. 1 ~. Labeled same as holotype (~ FSCA).

Distribution. Ecuador ( Map 2).

Comments. No other species of Thyanta has the inner basal angle ofeach hemelytral membrane distinctly infuscated.

Etymology. Named for the infuscated basal angle of the hemelytral membrane.