Ischnopelta cordiformis Rosso & Campos

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 : 128-131

Ischnopelta cordiformis Rosso & Campos , sp. n. ( Figs. 5Q , 20–21 )

Etymology. The epithet refers to the shape of the male segment X. Latin: cordis = heart + formis = form, shape.

Type locality. BRAZIL, Mato Grosso, Santa Terezinha [-10.646111, -50.613056] .

Holotype. Male. BRAZIL, Mato Grosso, Santa Terezinha (mouth of Rio Tapirapé ), 26.XII.1962, B. Malkin. Deposited at Museu Paraense Emilio Goeldi ( MPEG), Belém ( PA), Brazil.

Paratypess. 1 male and 2 females. BRAZIL, Mato Grosso, Santa Terezinha (mouth of Rio Tapirapé ) , 1 female, 1.X.1963,[-10.646111, -50.613056],( CAS); Santa Terezinha ( Porto Velho ) , 1 female, 15.XI–15.XII.1962, R . Pinheiros, [-10.7728, -51.0056], ( DZUP); São Félix do Araguaia , 1 male, VI.1961, M . Alvarenga, [-11.6169, -50.6689], ( CAS) .

Description. The overall somatic morphology is as described for I. scutellata , except for the following features. Male and female respectively 2 and 2.1 times longer than wide. Head. Labium reaching the metacoxae. Labrum inserted anterior to half the distance between the anterior margin of the eyes and the apex of mandibular plates. Antennae segments I to III dark yellowish with brown blotches and punctures, segments IV and V brown; segments ratio: I>II<III<IV<V.

Thorax. Hemelytra: corium as long as scutellum; conspicuous spot at apex of radial vein.

Male. Apical margin of membrane of hemelytra convex; median portion of posterior margin of urosternite VII subrectilinear; urosternite VII reaching anteriorly the imaginary line connecting the spiracles of sternite V. Genitalia. Pygophore with dorsal rim concave ( Fig. 20C , dr) and ventral rim slightly concave ( Fig. 20D , vr). Posterolateral angles 0.5 times shorter than the rest of the pygophore, perpendicular to the frontal plane and divergent from the base ( Fig. 20C–E , pla). Setae short and sparse on posterior half of ventral and lateral surfaces of pygophore; setae long and dense on ventral rim and on ventral and apical margins of posterolateral angles. Segment X wider than long, surpassing the apex of posterolateral angles, but not the parameres; cordiform; apical margin sclerotized and emarginated; lateral margins sclerotized and covered by long setae, mid-longitudinal region membranous and with short and sparse setae ( Figs. 20C and E, X; 20L–M ). Parameres claviform, head wide, oblique to the frontal plane; outer margin sinuous, slightly concave on proximal half and strongly convex on distal half; inner margin sinuous, distal portion strongly sclerotized, sinuous; apical process convergent; setae covering the ventral distal half of the head, and the sclerotized area ( Figs. 20D , pa; 20F– I). Cup-like sclerites externally visible, apices rounded and subparalel. Phallus: proximal half of vesica broader laterally, dorsally flattened and ventrally expanded; distal half sinuous; secondary gonopore ventral and beveled ( Fig. 20J–K ).

Female. Membrane of hemelytra not reaching the posterior margin of mediotergite VIII, posterior margin convex; median portion of posterior margin of both mediotergite VIII and urosternite VII subrectilinear; projections on the lateral 1/3 of posterior margin of sternite VII undeveloped ( Fig. 21C ). Genitalia. Valvifers VIII wider than long; posterior margin sinuous, moderately oblique to the median line, portion on the sutural margins narrow and acutely rounded, lateral portion slightly concave; sutural margins subrectilinear and folded dorsally; surface convex, dark yellowish with brown punctures and setae on sutural margins and sutural angles ( Figs. 5Q ; 21C , vf8). Valvifers IX almost completely covered by valvifers VIII; lateral margin subrectilinear; setae on mid-basal portion of ventral surface ( Fig. 21C–D , vf9). Laterotergites IX not reaching the posterior margin of mediotergite VIII; lateral margin sinuous; setae on median portion of lateral margin and mid-basal portion of ventral surface ( Fig. 21C–D , la9). Thickening of vaginal intima subcircular, slightly wider than long; distal portion more sclerotized; apical margin slightly concave, ventral cone membranous, oval ( Fig. 21D , vi). Vesicular area: anterior portion to the collar 1/8 of the posterior portion; median duct anterior to the collar with slight proximal widening ( Fig. 21D , mdp); median duct posterior to the collar with both proximal and distal widening ( Fig. 21D , md); inner duct coiled in the proximal widening of the median duct ( Fig. 21D , id). Pars intermedialis and capsula seminalis not examined.

Measurements: Table 7.

Distribution. Brazil (Mato Grosso) ( Fig. 7 ).

Comments. Although the posterior margin of valvifers VIII of Ischnopelta cordiformis sp. n. is similar to I. montana sp. n., in I. cordiformis the sutural portion is more angular and the median portion is subrectilinear ( Figs. 5Q ; 21C , vf8), while in I. montana the sutural portion is strongly convex, and the lateral portion is concave ( Figs. 5R ; 37C , vf8). Besides that, the lateral abdominal margins in I. montana are delineate by an unpunctured narrow band where two subtriangular darkbrown spots are observed on the laterals of the urosternites (Fig, 37B), while in I. cordiformis the punctures extend close to the abdominal margins, leaving only small unpunctured areas, and the lateral spots are narrower and irregular, sometimes elongated (Fig, 21B). Lastly, females of I. cordiformis do not present sclerotized rims on the lateral 1/3 of posterior margin of urosternite VII. The undeveloped posterolateral angles, and the cordiform segment X with broad membranous area in I. cordiformis ( Figs. 20C–D , pla; 20L–M) allows to easily distinguish it from I. montana , whose posterolateral angles are more developed and subtriangular, and the segment X is rounded and strongly sclerotized ( Figs. 36C–D , pla; 36L–M).

Figures

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 7. Distribution of Ischnopelta cordiformis Rosso & Campos, sp. n.; Ischnopelta crassula Rosso & Campos, sp. n.; Ischnopelta cristulata Rosso & Campos, sp. n.; Ischnopelta guarani Rosso & Campos, sp. n.; Ischnopelta impunctata Rosso & Campos, sp. n.; Ischnopelta luteicornis (Walker, 1867); Ischnopelta magna Rosso & Campos, sp. n..

FIGURE 20. Ischnopelta cordiformis 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: dr, dorsal rim; pa, parameter; ph, phalloteca; pla, posterolateral angle; vr, ventral rim; vs, vesica; X, segment X.

FIGURE 21. Ischnopelta cordiformis Rosso & Campos, sp. n. Female. A, dorsal view; B, ventral view; C, genital plates ventroposterior view (45º); D, internal genitalia.Abbreviations: cl, collar; 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; od, external duct; odp, proximal external duct; t8, mediotergite VIII; va9, valvulae IX; vf8, valvifer VIII; vf9, valvifer IX; vi, thickening of vaginal intima; X, segment X.

FIGURE 36. Ischnopelta montana 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: dr, dorsal rim; pa, parameter; ph, phalloteca; pla, posterolateral angle; vr, ventral rim; vs, vesica; X, segment X.

FIGURE 37. Ischnopelta montana Rosso & Campos, sp. n. Female. A, dorsal view; B, ventral view; C, genital plates ventroposterior view (45º). Abbreviations: la8, laterotergite 8; la9, laterotergite 9; mpr, projection on the lateral third of posterior margin of sternite VII; t8, mediotergite VIII; vf8, valvifer 8; X, segment X.