Thyanta (Argosoma) brasiliensis Jensen-Haarup 1928
Creators: name: Rider, D. A.
name: Chapin, J. B.
Publisher: name: Zenodo
Year: 1991
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Pentatomidae
Thyanta
Thyanta brasiliensis

description: Thyanta (Argosoma) brasiliensis Jensen-Haarup
Figs. 245-259, Map 3
Thyanta brasiliensis Jensen-Haarup, 1928: 187, 189-190.
Thyanta humeralis Ruckes, 1956: 57-59, fig. 2. NEW SYNONYMY.
Diagnosis. Medium to large, robust; extremely variable in coloration. One form green to pale brown, usually with dark reddish-purple markings between humeral angles, on dorsal surface ofhead, and on apex of scutellum. Second form pale green to fuscous, sometimes tending to purplish, often with anterior two-thirds of pronotal disc much paler than rest, sometimes with numerous interstellate pale points on coria. Punctures usually concolorous with surface, sometimes brown.
Outer jugal margins nearly parallel for middle third of distance from eyes to apex (Fig. 246). Anterolateral margins of pronotum in dorsal view concave; humeral angles narrowly rounded to angulate, sometimes marked with black, extending beyond base of adjacent coria by one-half width of eye or more (Fig. 245); pronotal cicatrices not marked with black. Hemelytral membranes hyaline, often with a few brown flecks. Posterolateral angles of connexival segments usually piceous. Postspiracular black spots usually lacking, sometimes present in darker specimens; posterolateral angles of abdominal sternites piceous.
Mesia! margins of basal plates in caudoventral view nearly straight, separated basally; posterior margins sinuously convex; posteromesial angles narrowly rounded (Fig. 257). Sclerotized rod not at all swollen subapically, gradually tapering to a narrowly rounded apex; dilation of spermatheca single, but abruptly narrowed for distal third, ending a short distance from apex of sclerotized rod (Fig. 258); spermathecal duct with a moderate amount of coiling below proximal flange (Fig. 259). Posterior margin of pygophore in caudal view broadly U-shaped, medial portion nearly straight (Fig. 253); lateral angles ofpygophore and blunt chin-like protuberance prominent when viewed laterally (Fig. 256). Apex of each paramere narrowly rounded, nearly spinose in ectal view (Fig. 249); concave surface oriented more mediad than dorsad, apex narrowly rounded in medial view, shaft with prominent protuberance just below parameral head (Fig. 247); roughened, spiculate area on lateral surface obovate (Fig. 248). Each lateral conjunctiva! lobe of aedeagus with one acute diverticulum (Fig. 252); median penial lobes relatively large (Fig. 250); penisfilum medium in size; dorsomedial conjunctiva! lobe apparently absent (Fig. 251).
Types. Jensen-Haarup (1928) described T. brasiliensis from 1 ~ and l! i? without designating a holotype. The ~ labeled (a) "~" (b) " Type Coll. J=Hrp." (c) " Type " (d) " Thyanta brasiliensis J-Hrp Coll. Jensen Haarup." (e) "Lagoa Santa Reinhardt" is designated lectotype. The!i? labeled (a) "2" (b) " Type Coll. J=Hrp." (c) " Type " (d) "Rio de Janeiro Reinhardt" (e) " Thyanta brasiliensis Jensen-Haarup leg." is designated paralectotype. Both specimens were examined and are housed in the Universitets Zoologiske Museum (Copenhagen, Denmark).
Ruckes (1956) described T. humeralis from 9dd and 1022. The holotype was examined, although it is slightly larger than the type of T. brasiliensis, there is no other significant difference. The holotype of T. humeralis is located in the American Museum of Natural History (New York).
Distribution. Southern South America (Map 3).
Specimens examined. 163 specimens collected during every month of the year; deposited in AMNH, BMNH, CAS, CU, DAR, DBT, EGER, FSCA, IML, LHR, MCN, MGA, OSU, UEC, USNM, ZMB, ZMUC. PERU: Junfn: Satipo. Loreto: Guyabamba, near Iquitos. BRAZIL: Lagoa Santa; Rodcio. Esperfto Santo: Vitoria. Mato Grosso: Cuiaba. Mato Grosso do Sul: Corumba; Miranda. Minas Gerais: Varginha. Para: Jacareacanga. Parana: 5 mi E Maravilha. Rio de Janeiro: Rio de Janeiro; Teresopolis. Rio Grande do Sul: Porto Alegre. Santa Catarina: Anita Garibaldi Est.; Nova Teut6nia. Sii.o Paulo: Bebedouro; Campinas; Cosmopolis; Indiana; Piracicaba. BOLIVIA: Villa Vicencia. Cochabamba: Chapare, Christal-Mayu. El Beni: Trinidad. La Paz: Coroico; Rurrenabaque. Santa Cruz: Buena Vista; Montero; Saavedra. PARAGUAY: San Luis. Alto Parana: Puerto Presidente Stroessner. Caaguazu: Estancia Primera. Central: Nueva Italia. Concepcion: Horqueta. Cordillera: Inst. Agro. Nae., Caacupe; San Bernardino; 20 km NW San Bernardino. Guaira: Villarica. Itapua: Trinidad. Paraguarf: Sapucai. Presidente Hayes: Gran Chaco. ARGENTINA: Cordoba: Sierra de Cordoba, Cosquin. Misiones: Apartado; Eldorado; Leandro Alem; Let; Puerto Iguazu; Puerto Rico; Victoria.
Comments. This species occurs in two fairly distinct color forms, but an examination of the genitalia of both sexes and other morphological characters reveals no significant differences. Because some specimens intermediate between the two forms do occur, it is believed that all specimens belong to a single variable species.
This species can be recognized from other congeners by the robust shape, sometimes by the dorsal coloration, often by the distinctly prominent humeral angles and the posteroventral production of the pygophore when viewed laterally, and by the shape of the parameres. Females can be identified by the shape of the spermatheca. It is the only species with the sclerotized rod not swollen subapically and with a single dilation of the spermatheca that is abruptly narrowed distally for a short distance.
description: Published as part of Rider, D. A. & Chapin, J. B., 1991, Revision Of The Genus Thyanta Stal, 1862 (Heteroptera: Pentatomidae) I. South America, pp. 1-77 in J. New York Entomol. Soc. 99 on pages 49-51