Thyanta (Argosoma) maculata (Fabricius)

Rider, David A. & Chapin, J. B., 1992, Revision of the genus Thyanta Stal, 1862 (Heteroptera: Pentatomidae) II. North America, Central America, and the West Indies., Journal N Y Ent Soc 100 (1), No. 1, pp. 42-98 : 80-83

Thyanta (Argosoma) maculata (Fabricius)

Figs. 138-152, Map 8

Cimex maculatus Fabricius, 1775: 704 .

Thyantacasta Stal, 1862b: 104; Stal, 1872:35; Uhler, 1876:7; Distant, 1880:66; Uhler, 1886:7; Uhler, 1894a: 23 l (part); Lethierry and Severin, 1893: 147; Kirkaldy, 1909: 94 (part); Malloch, 1919: 217, fig. 74; Torre-Bueno, 1939:231 (part); Froeschner. 1988:593 (part). NEW SYNONYMY.

Euschistus castus: Walker, 1867: 244 .

Thyanta maculata: Stal, 1872:35 ; Distant, 1893: 334; Lethierry and Severin, 1893: 148; Kirkaldy, 1909:94; Rolston and McDonald, 1984:fig. 29.

Diagnosis. General color green to brown; often with varying amounts of reddish on pronotum between humeral angles, often forming two oblong spots, one on each side of middle. Apices of scutellum and coria occasionally rubiginous.

Lateral jugal margins sinuous, not quite parallel ( Fig. 139). Anterolateral margins of pronotum nearly straight in dorsal view; humeral angles rounded to angulate, usually produced beyond base of adjacent corium by less than half width of eye ( Fig. 138); pronotal cicatrices immaculate. Ostiolar canals acuminate apically. Posterolateral angles of abdominal sternites piceous, sometimes only minutely so. Postspiracular spots usually absent, though sometimes present in brown form.

Basal plates with mesial margins slightly convex in caudoventral view, separated basally; posterior margins convex; posteromesial angles slightly emarginate ( Fig. 150). Sclerotized rod swollen subapically, narrowed apically ( Fig. 151); spermathecal duct moderately swollen and coiled below proximal flange ( Fig. 152). Posterior margin of pygophore broadly and shallowly U-shaped in caudal view ( Fig. 146); lateral angles prominent in ventral and dorsal views, chin-like protuberance relatively small ( Figs. 147, 148); emarginate below middle in lateral view ( Fig. 149). Apex of each paramere obtusely rounded in ectal view ( Fig. 141); concave surface oriented more mediad than dorsad, shaft rather robust with small medial protuberance ( Fig. 140); roughened spiculate area on lateral surface circular ( Fig. 142). Aedeagus with lateral and dorsomedial conjunctiva! lobes large ( Fig. 144), each lateral lobe with single, slightly sclerotized diverticulum ( Fig. 143); penisfilum and median penial lobes obscured by conjunctiva ( Fig. 145).

Types. Fabricius (1775) described Cimex maculatus from "America" without designating a holotype or paratypes. It is not possible to determine from his original description how many specimens he examined, but evidently he had more than one, as he mentions a variation. Only one syntype was located and examined. It is a 2 in poor condition (apex of abdomen destroyed, left forewing missing, etc.), but it does possess the characters that define this species. It has the following label data: (a) "maculatus" (b) "Thyanta maculata F.," and is here designated the lectotype. This specimen is housed in the Universetetets Zoologiske Museum (Copehagen, Denmark).

Stal (1862b) described T. casta from Mexico without designating a holotype or paratypes. One syntype, a!i!, was located and examined. Although it lacks the reddish markings that many specimens of T. maculata possess, it differs structurally in no significant manner from T. maculata. Because it is not possible to determine the number ofspecimens upon which Sill's description was based, the syntype specimen is designated the lectotype. It is labeled as follows: (a) "Mexico Coll. Signoret." (b) "Casta det. Stal" (c) " TYPE " (d) "Coll. Nat.-Mus. Wien" (e) "Thyanta casta STAL." The lectotype is housed in the Naturhistorisches Museum (Vienna, Austria).

Distribution. Southern Texas southward through Mexico and Central America to southern Panama ( Map 8).

Specimens examined. 499 specimens collected during every month of the year; deposited in AMNH, ARH, BMNH, CAS, CNC, CUC, DAR, DBT, EGER, ENGL, FSCA, INHS, LACM, LHR, LSU, MSU, MSUE, OSU, OSUC, SMEK, TAMU, UAT, UCB, UCS, UGA, UMAA, UNAM, UNSM, UUSL. UNITED STATES: Texas: Brazos . Burnet: Inks Lake State Park . Cameron: Boca Chica ; 3 mi SW Boca Chica ; Brownsville ; Harlingen ; Sabal Palm Grove Sanctuary near Southmost . Hidalgo: Bentsen Rio Grande Valley State Park ; Edinburg ; McAllen ; Progresso ; Santa Ana Natl Wildlife Refuge . Kleburg: Kingsville . Presidio: Presidio . San Patricio: Corpus Christi Lake State Park ; Nueces River , 5 mi SW Mathis . Starr: Falcon Heights ; 4-15 mi N Roma . Webb: Laredo . Zapata: 1 mi E Falcon Lake ; Falcon State Park .

MEXICO: Campeche: Calkini ; 12 mi E Campeche ; El Remate ; Escarcega ; Ruinas Edzna ; km 54 , Carr. Campeche-Merida . Chiapas: Aguacero , 16 km W Ocozocoautla ; Chicoasen Dam Area ; 13 mi W Cintalpa ; 2 mi N Ocozcoautla ; Ruinas Bonampak ; San Cristobal de las Casas ; Santo Domingo , 15 mi SE Simojovel ; Simojovel ; Suchiapa . Coahuila: Arroyo de la Zorra . Colima: 2 mi N Manzanillo . Guerrero: Acapulco de Juarez ; 3.7 mi E Marquelia ; Tecpan de Galeana . Hidalgo: Otongo . Jalisco: Chamela ; Estacion de Biologia Chamela . Michoacan: Acahuato . Morelos: 4.4 mi E Cuernavaca ; Villa dtt Ayala . Nayarit: l 5 km E San Blas . Nuevo Leon: Apodaca ; 3 mi E Galeana ; 16 mi S Linares , Anegade Arroyo ; 4.1 mi S Montemorelos ; Monterrey ; 4 mi S Monterrey ; 5 mi S Monterrey , Valle Alto ; 6 mi S Monterrey . Oaxaca: 2. 7 mi NW El Camaron ; El Charquito ; 6 mi W Jalapa del Marques ; 8 mi N La Ventosa ; Puerto Escondido ; Salina Cruz ; Tehuantepec ; 11 mi W Tehuantepec ; 12 mi W Tehuantepttc ; 13 km W Tehuantepec ; 44 mi W Tehuantepec ; 2.1 mi NW Totolapan . Queretaro: 1 mi NW Ayutla . Quintana Roo: 1 km N Coba ; 20 km N Felipe Carrillo Puerto ; 54 mi SE Peto ; San Isidrio Puerto Morelos ; 2 mi NE San Miguel ; River El Ramonal ; Rancho El 24 ; Xcun Nuevo ; km 146, Carr. Chetumal-Cancun ; km 146, Carr. Chetumal-Pto Juarez . San Luis Potosi: 12 mi S Ciudad Mante ; Ciudad Valles ; l l km E Ciudad Valles ; El Banito ; El Saito Falls ; Tamazunchale ; 5 mi N Tamazunchale ; 30 mi S Tamazunchale ; Tamuin . Sinaloa: l mi NW El Venadillo ; Mazatlan ; 5 mi N Mazatlan ; 10 mi S Mazatlan ; Presidio River near Caton . Sonora: 7 mi W Alamos . Tamaulipas: Abasolo ; Antiguo Morelos ; Bocatoma , Ciudad Victoria ; 6 mi S Ciudad Victoria ; 25 mi S Ciudad Victoria ; 5 mi SSE Gomez Farias ; 6 mi S Gomez Farias ; Guemes ; Hidalgo ; 8 mi N Jimenez ; La Pesca ; Llera ; 5 mi N Llera ; 13 km E Magiscatzin ; Punta Piedras ; Rio Corona , 30 km N Ciudad Victoria ; San Fernando ; 6.2 mi S San Fernando ; 25 mi SE San Fernando ; Tampico ; Villagran . Veracruz: Cordoba ; Cotaxtla ; Cotaxtla Expt Stn ; Cuitlahuac ; Lake Catemaco Area ; Ojo de Agui ; Puente Nacionale ; San Andres Tuxtla ; 5 mi S Santiago Tuxtla ; Tolome ; 10 mi W Veracruz . Yucatan: Chichen Itza ; Piste ; Progreso ; 12 km N Quintana Roo, Hwy 295 ; 13 mi E Valladolid ; 13.3 mi S Valladolid ; 1 km S Xcalacoop ; IO km N Xcalacoop .

BELIZE: Belize: 12 mi NW Belize City . EL SALVADOR: Ruinas San Andres .

HONDURAS: Choluteca . Comayagua: 5 mi NW Comayagua . Cortes: Puerto Cortes .

NICARAGUA: Chinandega; N side Cosgoina Volcano , Gulf of Fonseca . Managua: Jiloa ; Masachapa . COSTA RICA: Limon. Guanacaste: La Pacifica , near Canas. PANAMA: Chitre; La Chorrera . Canal Zone: Barro Colorado Island ; Base of Cerro Galera . Darien: Santa Fe.

Commenis. Thyanta maculata was originally distinguished from other congeners by the presence of two oblong reddish macules, one on each side of the middle of the pronotum. Fewer than half the specimens of T. maculata actually exhibit this character. Also, several other species of Thyanta are known to have the same type of maculation in at least some specimens ( T. pseudocasta Blatchley , T. brasiliensis Jensen-Haarup , T. curvata Rider ).

Thyanta maculata can be separated from other congeners except T. pseudocasta by the structure of the male genitalia. Each paramere is rather robust with the apex rounded, and the dorsomedial concave surface is oriented more mediad than dorsad. Thyanta pseudocasta has very similar male genitalia, but the aedeagus is slightly different. The aedeagus of T. maculata has a dorsomedial conjunctival lobe, while the same structure is apparently absent in T. pseudocasta. The two forms can usually be separated based upon the prominence of the humeral angles. Each humeral angle in T. maculata is usually produced beyond the base of the adjacent corium by less than half the width of an eye, while in T. pseudocasta each humeral angle usually protrudes beyond the corium by more than half the width of an eye.

Thyanta maculata is a variable species, especially with respect to size and coloration. For example, specimens from the Yucatan peninsula ofMexico average much smaller than specimens from other parts of the range, but they do not differ in any other significant manner.