Thyanta (Phacidium) robusta Rider, 1991

Thyanta (Phacidium) robusta Rider , new species

Figs. 124- 138, Map 4

Description. Medium to large; dorsal surface dusky brown to greenish brown; broadly ovate, robust. Punctures brown, usually becoming fuscous near each humeral angle and in irregular band just posterior to transhumeral pale subcalloused line.

Apex of head evenly rounded; outer jugal margins nearly parallel for middle third of distance from eyes to apex ( Fig. 125). Antennae brown, segments 1-2 sometimes vaguely marked with fuscous, segments 3-5 often reddish. Anterolateral margins of pronotum concave in dorsal view; humeral angles produced anterolaterad and dorsad, spinose ( Fig. 124). Mesia! angle of each pronotal cicatrice marked with fuscous, sometimes only vaguely so. A raised transhumeral subcalloused line usually present. Disc of pronotum anterior to cicatrices depressed, punctures crowded, small. Hemelytra with exocorium of each more densely punctate than rest of corium; posterior margin of corium convex, costal angle narrowly rounded, usually reaching beyond middle of penultimate connexival segment ( Fig. 124); hemelytral membranes hyaline with numerous fuscous flecks. Connexiva green to brown, posterolateral angles black, sometimes posterior margin of each segment marked with fuscous.

Ventral surface pale brown to green; punctures usually concolorous with surface, sometimes pale brown. Rostrum pale brown to green, apical half ofsegment 4 piceous, reaching to anterior margin of third (second visible) abdominal sternite. Ostiolar canals acuminate apically. Humeral angles often piceous. Femora and tibiae pale brown, tarsal segments darker, reddish; femora sometimes marked with a few pale brown spots, usually one dark brown to fuscous spot on superior surface at distal third. Postspiracular black spot usually present on each side of each abdominal sternite; posterolateral angle of each abdominal sternite piceous.

Mesial margins of basal plates in caudoventral view nearly straight; posterior margins sinuously convex; posteromesial angles weakly emarginate ( Fig. 136). Sclerotized rod swollen subapically, distinctly narrowed apically ( Fig. 137); spermathecal duct slightly swollen and coiled below proximal flange ( Fig. 138). Posteroventral surface ofpygophore arcuately rounded; posterior margin in caudal view U-shaped, medial portion concave ( Fig. 132). Pygophore in lateral view emarginate on dorsal half ( Fig. 135); each lateral angle appearing double-cone-shaped in both ventral and dorsal views ( Figs. 133, 134). Each paramere robust, apex nearly spinose in medial view ( Fig. 126); apex narrowly rounded, curved slightly mediad in ectal view ( Fig. 128); roughened, spiculate area on lateral surface linear, short ( Fig. 127). Each lateral conjunctiva! lobe ofaedeagus with 1-2 diverticula ( Fig. 131); dorsomedial conjunctiva! lobe apparently absent ( Fig. 130); penisfilum and median penial lobes prominent ( Fig. 129).

Measurements. Total length 7.41-9.78 (7.41); total width 6.47-8.04 (6.47); medial length ofpronotum 1.71- 1.99 (1.71). Medial length of scutellum 3.31-4.08 (3.40); basal width 3.20-3.84 (3.28); width at distal end of frena 1.21-1.66 (1.40). Length ofhead 1.62-1.81 (1.62); width 2.08-2.36 (2.12). Length of segments 1-5 ofantennae 0.40-0.52 (0.40), 0.81-0.94 (0.81), 1.07-1.20 (1.07), 1.14-1.25 (1.14), and 1.16- 1.21 (1.21), respectively. Length of segments 2-4 ofrostrum 1.25-1.62 (1.25), 0.74-0.81 (0.74), and 0.77-0.96, respectively.

Holotype. 5 labeled "ANA RECK (MUN. CAXIAS DO SUL R. S. 9-IV-55, BRASIL E. W. GRUMAN leg." Deposited in the Florida State Collection of Arthropods (Gainesville) .

Paratypes. 255, 522. Labeled same as holotype (5 FSCA) ; (a) " SAO PAULO Br., Mraz " (b) "Z.M.B. Hem." (5 ZMB) ; (a) " Gramado, R.G. do Sul, Brasil 6-1-50 J. Becker 123" (b) " Thyanta det RISailer" (c) " Thyanta acuta Ruckes varietal form" (d) "Compared with type. Much more robust. H. Ruckes" (2 USNM) ; " GRAMADO 2. 1954 RGS BRASIL " (2 MZRS) ; " Brazil, Parami 30 mi. W Irati 23 FEB 1980 D.B. Thomas Coll." (2 DBT) ; (a) " Tasimbe 2411 57'' (b) "218" (2 MZRS) ; and (a) " Pinheinal 28 I 53 " (b) "217" (2 MZRS) .

Distribution. Brazil ( Map 4).

Comments. This is a fairly distinctive species, although it is closely related to T. acuta and T. cornuta . It can be separated from these species by the larger, more robust shape, and by the characters of the male genitalia. The double-cone-shaped posterolateral angles of the pygophore in ventral and dorsal views will separate this species from both T. acuta and T. cornuta .

Etymology. Named for the robust form of the humeral angles.