Ischnopelta scutellata ( Signoret, 1851 )

Rosso, Pedro & Campos, Luiz Alexandre, 2021, Revision of Ischnopelta Stål, 1868 with the description of twenty new species (Hemiptera: Pentatomidae: Discocephalinae), Megataxa 6 (2), pp. 96-184 : 104-114

Ischnopelta scutellata ( Signoret, 1851) ( Figs. 2 ; 5A ; 9–10 )

Discocephala scutellata Signoret, 1851: 334 .

Discocephala (Ischnopelta) scutellata: Stål, 1868: 18 ; Stål, 1872: 6; Lethierry & Severin, 1893: 84.

Ischnopelta scutellata: Berg, 1891: 238 ; Kirkaldy, 1909: 215; Rolston, 1990: 20; Grazia et al., 2015: 712.

Holotype. VENEZUELA. Muséum National d’Histoire Naturelle ( MNHN), Paris, France (examined).

Material examined. 20 males and 28 females. BRAZIL, Mato Grosso, Santa Teresinha (close to the outfall of Tapirapé river), 1 male, 14. I.1963, Borys Malkin, [-10.616111, -50.613056], ( CAS); Campo Novo do Parecis, Utiariti (Papagaio river), 4 males and 7 females, 22-31.X.1966, Lenko & Pereira ( K. Lenko Col.), [-13.0215, -58.2870], ( UFRG); Chapada dos Guimarães, 1 female, homotype (det. H. Ruckes, 1961), [-15.433333, -55.75], ( AMNH, Acc:23739); 3 males and 3 females, 01. II.1961, J. & B. Bechyné, [-15.433333, - 55.75], ( MPEG); 1 male, March, [-15.433333, -55.75], ( USNM); Cuiabá, 3 males and 1 female, 14. II.1961, J. & B. Bechyné, [-15.5960, -56.0970], ( MPEG); Tocantins, Palmas (Fazenda Céu, Serra do Lageado), 1 female, XI.1992, Exp. MCN / MZSP, [-10.1669, -48.3328], 6-96 ( MCNZ); Distrito Federal, Brasília , Planaltina (32 km N Brasília ), 1 male and 2 females, 17–21.XI.1997, T. J. Henry, [-15.4548, -47.6130], ( USNM); Goiás, Corumbá de Goiás (Fazenda Monjolinho), 1 female, 14. VI.1942, F. Lane, [-15.9275, -48.8103], ( UFRG); Minas Gerais, Cardeal Mota (4 km SW Cardeal Mota and Rio Cipó, Rod. MG 10), 2 males and 2 females, 6.XI.1997, T. J. Henry & A. Paula, [-19.3564, -43.655], ( USNM); Paracatu, 1 female, VI.1960, Exp. Formosa, [-17.2211, -46.8741], ( MNRJ); Pirapora, 1 female, XI.1975, M. Alvarenga, [- 17.3374, -44.9271], ( AMNH); Goiás, Jataí, (Fazenda Cachoeirinha), 2 males and 3 females, X.1962, Exp. Dep. Zool., [-17.8872, -51.7182], ( UFRG); (Fazenda Nova Orlandia), 2 males and 2 females, 1964, Martins, Morgante & Silva, [-17.8872, -51.7182], ( UFRG); São Paulo, Pereira Barreto (old village from Lussanvira, Zone of the old Estrada de Ferro Noroeste Brazil— N. O. B.), 1 male and 1 female, 4.X.1938, Instituto Oswaldo Cruz, [-20.651389, -51.072222], ( FIOC); Ribeirão Preto, 1 female, 11.XII.1995, A. M. de Faria, [-21.1794, -47.7999], (UNIFESP), 1 female, III.1996, A. M. de Faria, [-21.1794, -47.7999], (UNIFESP).

Description. Male and female respectively 1.8 and 1.9 times longer than wide; dorsal surface somewhat glossy and dark yellowish; ventral surface pale yellow.

Head two times wider than long; anterior margin slightly emarginated. Clypeus 0.4 times the length of head. Distance between ocelli 0.3 times the distance between the eyes, on the line connecting the inner angles of the eyes. Maxillary plates and ventral ocular peduncles paleyellow; punctures on bucculae scarce, denser on ocular peduncles. Bucculae low, not concealing the first labial segment. Labium slightly surpassing the metacoxae. Labrum inserted halfway between the anterior margin of the eyes and the apex of mandibular plates. Antennae light brown, with irregular reddish striated blotches on segments II and III; segments ratio: I=II<III<IV<V.

Thorax. Pronotum as long as the head; width at the anterolateral angles as wide as the head. Scutellum surpassing the apical angles of urosternite VI, 1.8 times longer than wide at base; post-frenal lobe 1.6 times longer than frenal; post-frenal lobe narrowly rounded at apex. Hemelytra: corium slightly shorter than scutellum; in some specimens the radial vein is continued by a reddish line; apical margin of hemelytral membrane convex. Pro-, meso-, and metapleura pale-yellow, moderately punctured. Evaporatorium reaching the lateral margin of mesopleura. Legs dark yellowish, femora with punctures and reddish striated blotches on distal half, tibiae moderately punctured, setae on posterodorsal margin of protibiae longer than the others.

Abdomen dark yellowish; urosternites weakly punctured on median third, more densely on lateral thirds. Dark spots at the lateral of urosternites narrow, the anterior one longer than the posterior; minute spine present at apical angles of urosternite VII.

Male. Median portion of the posterior margin of urosternite VII subrectilinear; urosternite VII surpassing anteriorly the imaginary line connecting the spiracles of urosternite V. Genitalia. Dorsal rim of pygophore subrectilinear ( Fig. 9C , dr); ventral rim shallowly concave ( Fig. 9D , vr). Posterolateral angles 1.3 times longer than the rest of the pygophore, perpendicular to the frontal plane, slightly bent ventrally, divergent from the base and slightly convergent at apex ( Fig. 9C–E , pla). Setae short and sparse on the posterior half of the ventral and lateral surfaces of the pygophore, and on the lateral surface of the posterolateral angles; setae long and dense on the ventral rim, and on the ventral margin of the posterolateral angles. Segment X longer than wide, not reaching the apex of the posterolateral angles and parameres; oval, and deeply emarginated apically; lateral and apical margins sclerotized and covered by setae; basal margin and mid-longitudinal surface membranous ( Figs. 9C and E, X; 9L–M ). Parameres falciform, flat, as long as the posterolateral angles; distal portion oblique to the frontal plane; outer margin convex, inner margin sinuous, with strong excavation on the distal half; apex aculeiform, convergent, ventroposterioly directed; setae covering the posterior half of the ventral surface ( Fig. 9F–I ). Cup-like sclerites little developed. Phallus: vesica broader on proximal half, bearing ventral and lateral expansions, followed by a lateral curvature; distal half ( Signoret, 1851) specimens evaluated (n). curved ventrally; secondary gonopore ventrally directed and beveled ( Fig. 9J–K ).

Female. Membrane of hemelytra not reaching the posterior margin of mediotergite VIII; median portion of the posterior margin of mediotergite VIII and of sternite VII subrectilinear; projections on the lateral1/3of posterior margin of sternite VII laminate, semicircular and slightly oblique in relation to the sternite surface ( Fig. 10C , mpr).

Genitalia. Valvifers VIII as long as wide, sutural angles subrectilinear, lateral angles slightly concave; sutural margins subrectilinear and dorsally folded; surface dark yellowish with brown punctures and setae on the distal half of the sutural margins; longitudinal grooves narrow and shallow at the basal portion ( Figs. 5A ; 10C , vf8). Valvifers IX almost completely covered by the valvifers VIII; lateral margin convex; setae on the mid-basal portion of the ventral surface ( Fig. 10C–D , vf9). Laterotergites IX not reaching the posterior margin of mediotergite VIII; lateral margin convex; setae on the median portion of the lateral margin and mid-basal portion of the ventral surface ( Fig 10C–D , la9). Thickening of vaginal intima barrel-shaped, slightly wider than long; distal portion more sclerotized; lateral margins convex; distal margin sinuous with 1+1 processes on the laterals, ventrodistal cone with membranous subcircular apex ( Fig. 10D , vi). Vesicular area: anterior portion to the collar 1/5 of the posterior portion; median duct anterior to the collar slightly widened ( Fig. 10D , mdp); median duct posterior to the collar with proximal and distal widening ( Fig. 10D , md); inner duct coiled in the proximal widening ( Fig. 10D , id). Distal ductus receptaculi 0.54 times the length of vesicular area posterior to the collar ( Fig. 10D , drd, drp). Pars intermedialis barrel shaped, longer than capsula seminalis ( Fig. 10D , pi); annular crests convergent, diameter of the proximal crest slightly smaller than the distal one ( Fig. 10D , dac, pac). Capsula seminalis with two filiform lateral projections, one long and sinuous and the other short and slightly curved, both directed to the pars intermedialis ( Fig. 10D , cs, pr).

Measurements: Table 1 .

Distribution. Venezuela, Brazil (Tocantins, Mato Grosso, Goiás, Minas Gerais, Brasília (DF) , São Paulo) ( Fig. 6 ).

Comments.Males of this species are easily recognized by the parameres aculeiform at apex, convergent and ventroposteriorly directed (observed in posterior view of the pygophore) ( Fig. 9E , pa). Female identification is possible through the analysis of the posterior margin of valvifers VIII shaped as an open “V” with sutural angles subrectilinear and laterals slightly concave ( Figs. 5A , vf8; 10C, vf8).

Ischnopelta alalonga Rosso & Campos , sp. n. ( Figs. 5O ; 11–12 )

Etymology. The epithet refers to the length of the wings, which in this species surpass the posterior margin of mediotergite VIII. Latin: ala = wing + longus = long.

Type locality. BRAZIL, São Paulo, Piracicaba [- 22.7274, -47.6448] .

Holotype. Male. BRAZIL, São Paulo, Piracicaba, 3.IX.1986, F. D. Bennett. Deposited at Museu de Zoologia da Universidade de São Paulo ( MZSP)], São Paulo ( SP), Brazil.

Paratypes. 2 males and 14 females. BRAZIL, São Paulo, Piracicaba , 1 female, 3.IX.1986, F . D. Bennett, [- 22.7274, -47.6448], ( J. E. Eger, Personal collection) ; 3 females, 11. III .1987, F . D. Bennett, [-22.7274, -47.6448], ( J. E. Eger, Personal collection) ; 1 female, 28. I .1988, D. H. Haback & F . D. Bennett, [-22.7274, -47.6448], ( J. E. Eger, Personal collection) ; 1 male and 1 female, 20. II .1988, F . D. Bennett, [-22.7274, -47.6448], ( J. E. Eger, Personal collection); Campinas ( Campus UFU) , 1 male and 2 females, 19.XI.1990, [-22.9095, -47.0674], ( MZSP) ; 6 females, 19.XI.1990, [-22.9095, -47.0674], ( UFRG) .

Description. The overall somatic morphology is as described for I. scutellata , except for the following features. Head. Bucculae slightly higher than the first labial segment. Antennae yellow dorsally, and dark yellowish ventrally; segments ratio: I>II<III<IV<V.

Thorax. Pro-, meso- and metasternum not punctured. Evaporatorium not reaching the outer margin of mesopleura. Setae on posterodorsal margin of protibiae as long as the others.

Abdomen. Dark spots at the lateral of urosternites subtriangular, wide.

Male. Apical margin of membrane of hemelytra convex; urosternite VII not reaching anteriorly the imaginary line connecting the spiracles of urosternite V. Genitalia. Dorsal rim of pygophore sinuous ( Fig. 11C , dr); ventral rim slightly concave ( Fig. 11D , vr). Posterolateral angles 1.6 times longer than the rest of the pygophore, base and apex respectively perpendicular and oblique to the frontal plane, convergent from the base, dorsal margin folded into the pygophore ( Fig. 11C–E , pla). Setae short on the posterior half of ventral and lateral surfaces of the pygophore, and on the outer and inner surfaces of the posterolateral angles; setae long and dense on the lateral portions of the ventral rim, and on the ventral and apical margins of the posterolateral angles. Segment X longer than wide, surpassing the parameres, but not reaching the apex of the posterolateral angles, subrectilinear and strongly emarginated apically; lateral margins sclerotized and densely covered with long setae; mid-longitudinal region membranous and with sparse setae ( Figs. 11C and E, X; 11L–M ). Parameres clubshaped, swollen, and perpendicular to the frontal plane; inner and outer surfaces sinuous, distal portion of inner surface slightly concave, with transverse lines and a minute apical process; ventral surface sinuous; dorsal surface narrow, distal half strongly convex longitudinally; setae covering the apex ( Figs. 11D , pa; 11F–I). Cup-like sclerites externally visible and with apices rounded and slightly convergent ( Fig. 11D , cls). Phallus: proximal portion of vesica laterally biconcave, ventrally expanded; median portion subcylindrical, gradually narrowed and bent ventrally; distal portion subcylindrical and sinuous; secondary gonopore ventroposterior and beveled ( Fig. 11J–K ).

Female. Hemelytral membrane surpassing the posterior margin of mediotergite VIII, posterior margin convex; median portion of posterior margin of urosternite VII, and projections on its lateral 1/3 ( Fig. 12C , mpr) as described for I. scutellata . Genitalia. Valvifers VIII wider than long; posterior margin strongly sinuous, sutural portion slightly convex; lateral portion sinuous, slightly oblique to the midline and with slender cut on the lateral; sutural margins subrectilinear and folded dorsally; surface dark yellowish with brown punctures and setae on the distal half of the sutural margins and on the posterior margin; longitudinal grooves narrow and shallow at the basal portion ( Figs. 5O ; 12C , vf8). Valvifers IX exposed; lateral margin subrectilinear; setae on mid-basal portion of ventral surface ( Fig. 12C–D , vf9). Laterotergites IX not reaching the posterior margin of mediotergite VIII; lateral margin convex; setae on median portion of lateral margin and on mid-basal portion of the ventral surface ( Fig. 12C–D , la9). Thickening of vaginal intima subcircular, slightly wider than long; proximal margin concave and wider than the distal one; distal margin weakly emarginated; mid-ventral area with membranous elliptical cone, dorsal longitudinal ridges divergent distally and reaching the margins ( Fig. 12D , vi). Vesicular area: anterior portion to the collar 1/6.5 of the posterior portion; median duct anterior to the collar with slight proximal widening ( Fig. 12D , mdp); median duct posterior to the collar with proximal and distal widening ( Fig. 12D , md); inner duct coiled in the proximal widening ( Fig. 12D , id). Distal ductus receptaculi 0.40 times the length of the vesicular area posterior to the collar ( Fig. 12D , drd, drp). Pars intermedialis wider distally ( Fig. 12D , pi); proximal annular crest perpendicular to pars intermedialis, the distal one facing the pars intermedialis and almost twice the size the proximal ( Fig. 12D , dac, pac). Capsula seminalis globose, with a long and sinuous laterobasal projection directed to the pars intermedialis; & Campos, sp. n. specimens evaluated (n).

in some specimens, a lateral projection of variable size may occur ( Fig. 12D , cs, pr).

Measurements: Table 2.

Distribution. Brazil (São Paulo) ( Fig. 6 ).

Comments. Ischnopelta alalonga sp. n. ( Figs. 11A–B ; 12A–B ), although similar to Ischnopelta crassula sp. n. ( Figs. 23A–B; 23A–B ), presents the corium slightly shorter than the scutellum, and the lateral abdominal stripe unpunctured, better delimited and with dark-brown blotches, whilst in I. crassula the corium and scutellum are subequal, and the lateral abdominal stripe presents, besides the blotches, few irregularly distributed punctures. The dorsal rim of the pygophore is sinuous in I. alalonga ( Fig. 11C , dr) and slightly concave in I. crassula ( Fig. 22C , dr), the parameres with more developed apical process, and the area with differentiated texture in the inner surface is longer and narrow in I. alalonga ( Figs. 11F–I ; 22F–I ); the proximal portion of vesica is laterally biconvex in I. alalonga ( Fig. 11K , vs), while in I. crassula it is wider at the base and gradually narrows up to the curvature ( Fig. 22K , vs). The female hemelytral membrane surpasses the posterior margin of mediotergite VIII in I. alalonga ( Fig. 12A–B ), but not in I. crassula ( Fig. 23A–B ). The thickening of the vaginal intima forms a median and elliptical membranous cone, and the dorsal longitudinal ridges are sinuous and divergent distally reaching the margins in I. alalonga ( Fig. 12D , iv), while in I. crassula the cone is subtriangular, and the ridges are sinuous and not reaching the margins ( Fig. 23D , iv).

Figures

FIGURE 2. Ischnopelta scutellata (Signoret, 1851). A−C, antennal segments II and III, dorsal and laterodorsal views (30º and 45º), respectively; D−F, protibiae, lateral, dorsal and ventroposterior views, respectively. Abbreviations: gr, longitudinal groove; int, intumescence; rbr, row of bristles. Scale bars = 0.5 mm.

FIGURE 5. Female genital plates.A, Ischnopelta scutellata (Signoret, 1851); B, Ischnopelta bechyneorum Rosso & Campos, sp. n.; C, Ischnopelta confusa Rosso & Campos, sp. n.; D, Ischnopelta magna Rosso & Campos, sp. n.; E, Ischnopelta cylindrata Rosso & Campos, sp. n.; F, Ischnopelta impunctata Rosso & Campos, sp. n.; G, Ischnopelta luteicornis (Walker, 1867); H, Ischnopelta cristulata Rosso & Campos, sp. n.; I, Ischnopelta coralinae Rosso & Campos, sp. n.; J, Ischnopelta ruckesi Rosso & Campos, sp. n.; K, Ischnopelta pellucidula Rosso & Campos, sp. n.; L, Ischnopelta parvula Rosso & Campos, sp. n.; M, Ischnopelta vellozia Rosso & Campos, sp. n.; N, Ischnopelta wigodzinskyi Rosso & Campos, sp. n.; O, Ischnopelta alalonga Rosso & Campos, sp. n.; P, Ischnopelta crassula Rosso & Campos, sp. n.; Q, Ischnopelta cordiformis Rosso & Campos, sp. n.; R, Ischnopelta montana Rosso & Campos, sp. n.; S, Ischnopelta guarani Rosso & Campos, sp. n.; T, Ischnopelta marginella Rosso & Campos, sp. n.. Abbreviations: vf8, valvifers VIII; la8, laterotergites VIII; la9, laterotergites IX; mpr, projection on the lateral third of posterior margin of sternite VII; t8, mediotergite VIII; X, segment X. Scale bars = 1 mm.

FIGURE 6. Distribution of Ischnopelta alalonga Rosso & Campos, sp. n.; Ischnopelta anangulata Rosso & Campos, sp. n.; Ischnopelta bechyneorum Rosso & Campos, sp. n.; Ischnopelta cylindrata Rosso & Campos, sp. n.; Ischnopelta confusa Rosso & Campos, sp. n.; Ischnopelta coralinae Rosso & Campos, sp. n.; Ischnopelta scutellata (Signoret, 1851).

FIGURE 9. Ischnopelta scutellata (Signoret, 1851). Male.A, dorsal view; B, ventral view; C–E, pygophore: dorsal, ventral, and posterior views respectively; F–I, parameters: dorsal, ventral, external and internal lateral views, respectively; J–K, phallus: lateral and dorsal views, respectively; L–M, segment X, dorsal and ventral views, respectively. Abbreviations: dr, dorsal rim; pa, parameter; ph, phalloteca; pla, posterolateral angle; vr, ventral rim; vs, vesica; X, segment X.

FIGURE 10. Ischnopelta scutellata (Signoret, 1851). Female.A, dorsal view; B,ventral view, C, genitalplates ventroposterior view (45º); D, internal genitalia. Abbreviations: cl, collar; cs, seminalis capsule; dac, distal annular crest; drd, distal ductus receptaculi; drp, proximal ductus receptaculi; id, internal duct; idp, proximal internal duct; la8, laterotergite VIII; la9, laterotergite IX; md, medium duct; mdp, proximal medium duct; mpr, projection on the lateral third of posterior margin of sternite VII; od, external duct; odp, proximal external duct; pac, proximal annular crest; pi, pars intermedialis; pr, projection; t8, mediotergite VIII; va9, valvulae IX; vf8, valvifer VIII; vf9, valvifer IX; vi, thickening of vaginal intima; X, segment X.

FIGURE 11. Ischnopelta alalonga Rosso & Campos, sp. n. Holotype male.A, dorsal view; B, ventral view; C–E, pygophore: dorsal, ventral, and posterior views respectively; F–I, parameters: dorsal, ventral, external and internal lateral views, respectively; J–K, phallus: lateral and dorsal views, respectively; L–M, segment X, dorsal and ventral views, respectively. Abbreviations: cls, cup like sclerites; dr, dorsal rim; pa, parameter; ph, phalloteca; pla, posterolateral angle; vr, ventral rim; vs, vesica; X, segment X.

FIGURE 12. Ischnopelta alalonga Rosso & Campos, sp. n. Female. A, dorsal view; B, ventral view; C, genital plates ventroposterior view (45º); D, internal genitalia. Abbreviations: cl, collar; cs, seminalis capsule; dac, distal annular crest; drd, distal ductus receptaculi; drp, proximal ductus receptaculi; id, internal duct; idp, proximal internal duct; la8, laterotergite VIII; la9, laterotergite IX; md, medium duct; mdp, proximal medium duct; mpr, projection on the lateral third of posterior margin of sternite VII; od, external duct; odp, proximal external duct; pac, proximal annular crest; pi, pars intermedialis; pr, projection; t8, mediotergite VIII; va9, valvulae IX; vf8, valvifer VIII; vf9, valvifer IX; vi, thickening of vaginal intima; X, segment X.

FIGURE 22. Ischnopelta crassula Rosso & Campos, sp. n. Holotype male.A, dorsal view; B, ventral view; C–E, pygophore: dorsal, ventral, and posterior views respectively; F–I, parameters: dorsal, ventral, external and internal lateral views, respectively; J–K, phallus: lateral and dorsal views, respectively; L–M, segment X, dorsal and ventral views, respectively. Abbreviations: cls, cup like sclerites; dr, dorsal rim; pa, parameter; ph, phalloteca; pla, posterolateral angle; vr, ventral rim; vs, vesica; X, segment X.

FIGURE 23. Ischnopelta crassula Rosso & Campos, sp. n. Female. A, dorsal view; B, ventral view; C, genital plates ventroposterior view (45º); D, internal genitalia. Abbreviations: cl, collar; cs, seminalis capsule; dac, distal annular crest; drd, distal ductus receptaculi; drp, proximal ductus receptaculi; id, internal duct; idp, proximal internal duct; la8, laterotergite VIII; la9, laterotergite IX; md, medium duct; mdp, proximal medium duct; mpr, projection on the lateral third of posterior margin of sternite VII; od, external duct; odp, proximal external duct; pac, proximal annular crest; pi, pars intermedialis; pr, projection; t8, mediotergite VIII; va9, valvulae IX; vf8, valvifer VIII; vf9, valvifer IX; vi, thickening of vaginal intima; X, segment X.