Thyanta Stal, 1862

Thyanta Stal View in CoL

Thyanta Stal, 1862a:58 ; Stal, 1867:529; Stal, 1872:34-35; Distant, 1880:65; Summers, 1898:45;Kirkaldy, 1909:94; VanDuzee, 1917:5 l; Blatchley, 1926: 104, 112- 113; Jensen-Haarup, 1928:185- 186; Furth, 1974:21-22; Froeschner, 1981:71; McPherson, 1982:48, 76-77; Rolston and McDonald, 1984:74, 76.

Type species. Cimex perditor Fabricius, 1794 (by subsequent designation, Kirkaldy, 1909: XXX).

Diagnosis. Third (second visible) abdominal sternite lacking medial spine or tubercle. Each ostiolar ruga sulcate proximally, reaching at least ¾ distance from mesial margin of ostiole to lateral margin of metapleuron. Each buccula evanescent or arcuately truncate at posterior termination. Juga and tylus usually subequal in length; rostrum reaching at least to metacoxae. Femora unarmed; superior surface of each tibia usually sulcate. Width ofscutellum at distal end offrena ¾ or less basal scutellar width. Each paramere narrowly rounded to acute apically, lacking denticles, usually lacking lateral lobe, rarely with spinose lateral lobe.

Comments. The genus Thyanta is closely related to Cyptocephala Berg and Tepa Rolston and McDonald, from which it can be reliably separated only by differences in the male genitalia. Species of Cyptocephala and Tepa have the head of each paramere bearing a well-developed, apically rounded lateral lobe. Only two South American species of Thyanta have a similar lateral lobe, but in both species the apex of the lateral lobe is angulate or spinose. Cyptocephala further differs from Tepa and Thyanta in having a row of minute denticles between the lateral lobe and the apex of the paramere.

Jensen-Haarup (1928) described the subgenus Parathyanta within Thyanta . Rolston and McDonald (1984) placed Parathyanta as a junior synonym of Cyptocephala . At the same time they transferred four species from Thyanta to Cyptocephala and six species from Thyanta to Tepa . The species of both Cyptocephala and Tepa have been reviewed recently ( Rolston 1972, 1986; Rider 1986b).

The genus Thyanta is divided into three subgenera: Argosoma new subgenus, Phacidium Breddin , and Thyanta . Sixteen of the 20 species of Argosoma occur in South America. The eight species of Phacidium are all restricted to South America. The nominate subgenus contains nine species, only three of which are known to occur in South America.

KEY TO SOUTH AMERICAN SPECIES OF THYANTA

I. Juga distinctly longer than tylus and leaving small subquadrate sinus in front of tylus ( Fig. 49); superior surface of each tibia asulcate; segment 2 of each antenna at least 1.5 times length of segment 3 (southern South America) .... aeruginosa Berg Juga and tylus subequal in length or tylus slightly longer thanjuga; superior surface of each tibia sulcate; segment 2 of each antenna at most only slightly longer than segment 3 ............................................................................................. 2

2(1). Scutellum with medial longitudinal band calloused, pale ( Fig. 357), usually continuing onto pronotum; hemelytral membrane with vague fuscous band from distal end of scutellum to apex (Galapagos Islands) ................... similis Van Duzee Scutellum uncalloused, occasionally a thin medial line present on pronotum; hemelytral membrane not marked as above ................ 3

3(2). Inner basal angle of each hemelytral membrane fuscous ( Fig. 337); each humeral angle narrowly rounded to nearly acute, but not spinose ( Fig. 337) (Ecuador) .. - • - ........................................................... infuscata , n. sp. Inner basal angle of each hemleytral membrane hyaline, although membrane may have distal brown flecks; each humeral angle variable, but if inner basal angle of hemelytral membrane somewhat brownish then each humeral angle spinose.... 4

4(3). Posterior termination of each buccula roundly truncate ( Fig. 50); anterolateral pronotal margins slightly convex ( Fig. 64) (Ecuador, Peru) .......... convexa , n. sp. Posterior termination of each buccula evanescent ( Fig. 214); anterolateral pronotal margins straight to concave...................................... 5

5(4). Exocorium and apex of corium stramineous, remainder of corium somewhat translucent, brown to green; anterior disk of pronotum stramineous, contrasting with green to brown posterior disk; humeral angles nearly spinose ( Fig. 352) (Colombia, Ecuador) ......................................... straminea , n. sp. Exocorium pale brown to green, concolorous with corium, except sometimes corium reddish, corium not translucent; coloration of pronotum variable, but if bicolored then humeral angles not spinose.................................. 6

6(5). Anterolateral and posterolateral abdominal angles piceous; humeral angles spinose 7 Anterolateral abdominal angles never piceous; posterolateral abdominal angles variable; humeral angles variable.......................................... 8

7(6). Each humeral angle weakly spinose, spines short, protruding beyond base of adjacent corium by the width of an eye or less ( Fig. 16) (Galapagos Islands) ................................................................... setigera Ruckes jacent corium by more than the width of an eye (Fig. I) (southern U.S. to northern Argentina) ........................................... perditor (Fabricius) (part)

8(6). Ventral surface of each humeral angle distinctly margined with piceous; humeral angles distinctly angulate or spinose............................... 9 Ventral surface of each humeral angle usually concolorous with rest of propleuron, sometimes becoming reddish or brownish, but not piceous; humeral angles variable, but if coloration blackish then humeral angles rounded.................. I 0

9(8). Humeral angles robustly spinose, directed anterolaterad ( Fig. 124); in ventral and dorsal views posterolateral angles of pygophore appearing double-cone-shaped ( Figs. 133, 134) (southern Brazil) ........................... robusta , n. sp. (part) Humeral angles angulate but not spinose, somewhat retrorse ( Fig. 109); posterolateral angles of pygophore not double-cone-shaped in ventral and dorsal views ( Figs. 118, 119) (Bolivia, Argentina, Brazil).... acutangula Jensen-Haarup

10(8). Humeral angles distinctly spinose...................... 11 Humeral angles angulate, narrowly rounded, or broadly rounded............ 15

11(10). Anterolateral pronotal margins distinctly dentate for ¾ distance from head to humeral angles ( Fig. 32); lateral margins of body often pink; postspiracular black spots usually lacking (Chile)........... ........ rubicunda , n. sp. Anterolateral pronotal margins lacking teeth, or at most a few weak teeth near head; lateral margins of body not pink; postspiracular spots variable........ 12

12(11). Pronotum with transhumeral reddish band; mesial angles of pronotal cicatrices piceous; postspiracular black spots present; posterior margin of pygophore produced posterodorsad medially, with medial emargination ( Figs. 9, 10) (southern U.S. to northern Argentina).. perditor (Fabricius) (part) Pronotum lacking transhumeral reddish band, or if extensive areas ofred present on pronotum these forming two longitudinally oblong spots near middle on posterior disk; mesial angles of pronotal cicatrices and postspiracular spots variable; posterior margin of pygophore not produced medially ( Fig. 88), lacking medial emargination........................................................... 13

13(12). Humeral angles rather robust, directed anterolaterad ( Fig. 124); black spot on each posterolateral abdominal angle relatively large, larger than diameter of spiracle; in ventral and dorsal views posterolateral angles of pygophore appearing double-cone-shaped ( Figs. 133, 134) (southern Brazil) ......... robusta , n. sp. (part) Humeral angles smaller, directed laterad and usually only slightly anterad ( Figs. 139, 154); black spot on each posterolateral abdominal angle lacking or if present smaller than diameter of spiracle; posterolateral angles of pygophore not double-cone-shaped ( Figs. 148, 149, 163, 164) ..................................... 14

14(13). Apex of head broadly rounded ( Fig. 140); black spot on each posterolateral abdominal angle distinctly present; pygophore in lateral view sinuously convex ( Fig. 150); in caudal view posterior pygophoral margin broadly U-shaped ( Fig. 147) (southern and central South America) ............................. acuta Ruckes Apex of head narrowly rounded ( Fig. 155); black spot on each posterolateral abdominal angle lacking or minute; pygophore in lateral view concave ( Fig. 165); in caudal view posterior pygophoral margin broadly V-shaped ( Fig. 162) (Venezuela, Bolivia, Brazil)....................... ...... cornuta Ruckes

15(10). Males.................................. 16 Females .................................................. 28

16(15). Posteroventral surface of pygophore arcuately sulcate; posterior margin of pygophore with dense fringe of long hairs (southern South America) ...................................................................... fimbriata , n. sp. (part) Posteroventral surface ofpygophore asulcate; posterior margin ofpygophore with at most a few short hairs.............. ............................ I 7

17(16). Posteroventral surface of pygophore arcuately rounded, not produced into blunt chin-like protuberance (Chile, western Argentina) ............... juvenca StAI (part) Posteroventral surface of pygophore produced into blunt chin-like protuberance ......................................................................... 18

18(17). In ectal view each paramere armed with either a spinose or angulate lateral lobe ( Figs. 203, 219)............ .. .................... ..... .............. 19 Each paramere unarmed laterally.......................................... 20

19(18). In ectal view lateral lobe of each paramere triangular ( Fig. 219); in medial view apex of each paramere curving dorsad and caudad forming a distinct hook ( Fig. 217) (Colombia, Peru) ................................... hamulata , n. sp. (part) In ectal view lateral lobe of each paramere spinose ( Fig. 203); in medial view apex of each paramere curving gently dorsad, but not forming distinct hook ( Fig. 20 I) (southern South America) .............................. acuminata Ruckes (part)

20( I 9). Lateral walls of genital cup each with elongate black carina; roughened spiculate area on lateral surface of each paramere linear, elongate ( Fig. 233) (Peru, Bolivia, northern Argentina)................................... boliviensis , n. sp. (part) Lateral walls of genital cup each with black tubercle; roughened spiculate area on lateral surface of each paramere circular, localized............ 21

21 (20). Occurring north of the equator...................... 22 Occurring south of the equator.............................. 26

22(21). Posterior margin of pygophore in caudal view broadly and sinuously V-shaped ( Fig. 302) (Colombia, Venezuela) ........................... sinuata , n. sp. (part) Posterior margin ofpygophore in caudal view broadly U-shaped............. 23

23(22). In medial view apex of each paramere rounded, angled dorsad nearly 60 degrees from longitudinal axis of head ofparamere ( Fig. 287) (Venezuela) ...................................................................... curvata , n. sp. (part) In medial view apex of each paramere variable, but if rounded then not angled dorsad beyond 45 degrees from longitudinal axis of head of paramere......... 24

24(23). In ectal view apex of each paramere obtusely rounded ( Fig. 312) (Colombia, Venezuela) ................................................ obtusa , n. sp. (part) In ectal view apex of each paramere narrowly rounded to spinose............. 25

25(24). In medial view each paramere with apex straight or bending slightly ventrad ( Fig. 272), concave ectal surface oriented more mediad than dorsad (Trinidad and Tobago, Venezuela) ....................................... vadosa , n. sp. (part) In medial view each paramere with apex curving gently dorsad ( Fig. 171), concave ectal surface oriented more dorsad than mediad (Lesser Antilles, northern South America) ............................................... testacea (Dallas) (part)

26(21). In medial view apex of each paramere spinose, lacking obtuse protuberance on shaft ( Fig. 186) (central and southern South America) ......... patruelis (Stal) (part) In medial view apex of each paramere usually rounded, presence of obtuse protuberance on shaft variable, but if apex of paramere is nearly spinose then protuberance is well-developed............................................... 27

27(26). In medial view apex of each paramere narrowly rounded, shaft with prominent obtuse protuberance ( Fig. 247) (central and southern South America) ........................................................ brasiliensis Jensen-Haarup (part) In medial view apex of each paramere broadly rounded, shaft lacking obtuse protuberance ( Fig. 324) (coastal desert from southern Ecuador to northern Chile) ......................................................... xerotica , n. sp. (part)

28(15). Posteromesial angle of each basal plate distinctly and moderately excavated... 29 Posteromesial angle of each basal plate rounded or only slightly emarginate.... 31

29(28). Concavity resulting from excavations in basal plates with sides distinctly divergent ( Fig. 282) (Trinidad and Tobago, Venezuela) ................. vadosa , n. sp. (part) Concavity resulting from excavations in basal plates with sides subparallel or slightly convergent....................................................... 30

30(29). Concavity resulting from excavations in basal plates nearly as long as wide ( Fig. 262); surface of basal plates distinctly rugose; distal end of sclerotized rod nearly linear, gradually becoming narrower towards apex ( Fig. 263) (Peru) ................................................................. emarginata , n. sp. (part) Concavity resulting from excavations in basal plates distinctly wider than long ( Fig. 267); surface of basal plates weakly rugose; distal end of sclerotized rod swollen subapically, narrowed apically ( Fig. 268) (Colombia, Venezuela) .......... .................................................... excavata , n. sp. (part)

31 (28). Distal end of sclerotized rod nearly linear, gradually becoming narrower towards apex .................................................................... 32 Distal end of sclerotized rod swollen subapically, narrowed apically........... 34

32(31). Dilation of spermatheca constricted in middle, appearing doubly inflated ( Fig. 228) (Colombia, Peru) ................................... hamulata , n. sp. (part) Dilation ofspermatheca not constricted in middle, may be narrowed apically, but appearing as single inflation............................................ 33

33(32). Dilation of spermatheca with inflated portion abruptly narrowed for apical third, ending near apex of sclerotized rod ( Fig. 258) (central and southern South America) ............................................... brasiliensis Jensen-Haarup (part) Dilation of spermatheca with inflated portion not abruptly narrowed, reaching about ¾ distance from base to apex of sclerotized rod ( Fig. 243) (Peru, Bolivia, northern Argentina)..................... boliviensis , n. sp. (part) 34(31). Spermathecal duct swollen into distinct cylindrical structure below proximal flange ( Fig. 93) (southern South America) ........................ fimbriata , n. sp. (part) Spermathecal duct may be swollen and coiled below proximal flange, but not forming distinct cylindrical structure...................................... 35

35(34). Dorsal punctation minute, dense, surface appearing matte (Chile, western Argentina) ....................................................... juvenca Stal (part) Dorsal punctation coarse, relatively sparse, surface glossy, shiny............... 36

36(35). Spermathecal duct with large amount of swelling and coiling below proximal flange, swelling carrot-shaped ( Figs. 183, 198)........ ...................... 37 Spermathecal duct with relatively small amount of swelling and coiling below proximal flange, swelling not carrot-shaped................................. 38

37 (36). Occurring in Lesser Antilles, Colombia, Venezuela, and Surinam ..................................................................... testacea (Dallas) (part) Occurring in southern Peru and central Brazil south to Argentina ...................................................................... patruelis (Stal) (part)

38(36). Occurring north of the equator............................................ 39 Occurring south of the equator............................................ 41

39(38). Usually with two longitudinally oblong reddish transhumeral spots, one on each side of middle (Colombia, Venezuela) ....................... curvata , n. sp. (part) Dorsal surface lacking all reddish markings................................. 40

40(39). Outer jugal margins subparallel for middle third of distance from eyes to apex of head ( Fig. 309) (Colombia, Venezuela) ....................... obtusa , n. sp. (part) Outer jugal margins sinuous, not parallel ( Fig. 301) (Colombia, Venezuela) .............................................................. sinuata , n. sp. (part)

41(38). Occurring in the coastal desert from southern Equador to northern Chile .............................................................. xerotica , n. sp. (part) Occurring in Bolivia, Brazil, Paraguay, and Argentina ..... acuminata Ruckes (part)