Revision of Ischnopelta Stål, 1868 with the description of twenty new species (Hemiptera: Pentatomidae: Discocephalinae) Author Rosso, Pedro Author Campos, Luiz Alexandre text Megataxa 2021 2021-11-18 6 2 96 184 journal article 3114 10.11646/megataxa.6.2.3 80116c4c-868f-4c71-b68f-66c4489d1375 2703-3090 5752808 Ischnopelta confusa Rosso & Campos , sp. n. ( Figs. 5C , 16–17 ) Etymology . Epithet proposed by Dr. H. Ruckes as registered in the manuscripts found with the specimens used in the study. He considered the species could be easily confounded with I. scutellata , from which the epithet is inferred. Latin: confusio = mixture, disorder. Type locality. ARGENTINA , Formosa , Formosa [ - 26.366667 , -58.583333 ] . Holotype . Male. ARGENTINA , Formosa , Formosa ( 45 km SW Formosa ), 28.I.1989 , C . W . & L . B . O’Brien & G . Wibmer. Deposited at Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” ( MACN ), Buenos Aires , Argentina. Paratypes . 3 males and 4 females . ARGENTINA , Misiones , Loreto , 2 males and 2 females , IX.1954 , [ - 27.3364 , -55.5222 ], ( AMNH ) ; 1 female , XII.1955 , [ - 27.3364 , -55.5222 ], ( UFRG ); Santa Maria , 1 male and 1 female , XI.1962 , M . J . Viana, [ -27.9036 , -55.3854 ], ( MACN ) . Description . The overall somatic morphology is as described for I. scutellata , except for the following features. Dorsal body surface brownish. Head. Labium reaching the metacoxae. Labrum inserted posterior to half the distance between the anterior margin of the eyes and the apex of mandibular plates. Antennae: segments I to III dark yellowish, segments IV and V dark brown; segments ratio: I>II<III≤IV<V. Thorax. Hemelytra: conspicuous spot at apex of radial vein. Pro-, meso- and metapleura densely punctured. Setae on posterodorsal margin of protibiae as long as the others. Abdomen. Dark spots at the lateral of urosternites wide and irregularly shaped. Male . Apical margin of the membrane of hemelytra subrectilinear; urosternite VII not reaching anteriorly the imaginary line between the spiracles of sternite V; posterolateral angles of urosternite VII unarmed. Genitalia . Dorsal rim of pygophore concave, ventral rim slightly concave ( Figs. 16C , dr; 16D, vr) with 1 + 1 lateral subtriangular projections ( Fig. 16C–E , pr). Posterolateral angles almost as long as the rest of the pygophore, perpendicular to the frontal plane and subparallel to each other ( Fig. 16C–E , pla). Setae short and sparse on posterior half of ventral and lateral surfaces of the pygophore, and on the outer surface of posterolateral angles; long setae on ventral rim, forming a 1 + 1 tufts on median portion; setae on the inner surface of posterolateral angles. Segment X slightly wider than long, surpassing the apex of posterolateral angles and parameres; apical margin subrectilinear; lateral margins strongly convex; basal and apical margins and mid-basal regions membranous; covered by long setae ( Fig. 16L–M ). Parameres spatulate, flat, longer than posterolateral angles and subparallel to the frontal lobe; outer margin sinuous on proximal half and strongly convex on distal half; inner margin sinuous, distal portion with a recession followed by a short process, truncate and convergent; apical margin convex; head ventral surface with an oblique crest, setose ( Fig. 16F–I ). Cup-like sclerites externally visible and with subparallel apices ( Fig. 16D , cls). Phallus: proximal half of vesica almost as wide as phallotheca; distal half of vesica strongly sclerotized, sinuous, and gradually tapering, distal portion posteriorly directed; secondary gonopore circular ( Fig. 16J–K ). FIGURE 16. Ischnopelta confusa 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; pr, ventral rim projection; vr, ventral rim; vs, vesica; X, segment X. FIGURE 17. Ischnopelta confusa 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. TABLE 5. Measurements (mean, standard deviation, minimum and maximum) and number of Ischnopelta confusa Rosso & Campos , sp. n. specimens evaluated (n).
Body structure Measurements performed n Male Measurements (mm) n Female Measurements (mm)
Body tl mw 4 8.13±0.50; (7.75–8.82) 4.22±0.19; (4.00–4.45) 4 9.60±0.32; (9.17–9.93) 5.11±0.15; (4.90–5.21)
hl 1.73±0.10; (1.64–1.88) 1.91±0.10; (1.79–1.97)
cl 0.52±0.03; (0.49–0.55) 0.60±0.01; (0.59–0.60)
Head hw 4 3.26±0.10; (3.14–3.38) 4 3.60±0.06; (3.53–3.64)
iod 0.90±0.02; (0.89–0.92) 1.01±0.01; (1.00–1.03)
ied 2.61±0.05; (2.53–2.66) 2.90±0.04; (2.87–2.95)
pl 1.64±0.07; (1.59–1.74) 1.94±0.03; (1.91–1.97)
Pronotum haw 4 3.77±0.16; (3.58–3.95) 4 4.33±0.07; (4.26–4.40)
aaw 3.22±0.10; (3.11–3.35) 3.57±0.06; (3.53–3.64)
sl 4.56±0.21; (4.36–4.85) 5.53±0.19; (5.35–5.69)
fll 1.80±0.05; (1.74–1.84) 2.14±0.06; (2.09–2.22)
Scutellum pfl 4 2.77±0.24; (2.57–3.12) 4 3.39±0.22; (3.13–3.58)
bsw 2.42±0.08; (2.31–2.49) 2.78±0.14; (2.58–2.90)
fcw 1.69±0.05; (1.63–1.75) 1.97±0.12; (1.81–2.06)
I 0.51±0.02; (0.50–0.53) 0.51±0.02; (0.50–0.53)
Antennae II III 3 0.39±0.02; (0.37–0.40) 0.81±0.05; (0.78–0.87) 3 0.45±0.02; (0.43–0.47) 0.81±0.04; (0.78–0.84)
IV 0.84±0.05; (0.81–0.90) 0.82±0.11; (0.74–0.90)
V 1.21±0.11; (1.15–1.33)
I 0.53±0.00; (0.53–0.53) 0.53±0.09; (0.47–0.59)
Labium II III 2 1.12±0.04; (1.09–1.15) 0.47±0.00; (0.47–0.47) 2 1.27±0.04; (1.24–1.30) 0.54±0.02; (0.53–0.56)
IV 0.33±0.02; (0.31–0.34) 0.33±0.02; (0.31–0.34)
Legend : tl, total length; mw, maximum width (at the sternite III level); hl, head length; cl, clypeus length; hw, head width; iod, interocellar distance; ied, interocular distance; pl, pronotum length; haw, pronotum width at the level of humeral angles; aaw, pronotum width at the level of anterolateral angles; sl, scutellum length; fll, frenal lobe length; pfl, post-frenal lobe length; bsw, basal scutellum width; fcw; scutellum width at the level of frenal constriction; I, II, III, IV and V, antennal and labium segments length. Female. Membrane of hemelytra not reaching the posterior margin of mediotergite VIII, posterior margin convex; median portion of posterior margin of mediotergite VIII and median portion of posterior margin of sternite VII concave; projections of urosternite VII as described for I. scutellata ( Fig. 17C , mpr). Genitalia : Valvifers VIII as wide as long, posterior margin sinuous; sutural margins subrectilinear and dorsally folded; surface dark yellowish, with brown punctures and setae on the distal portion of sutural rim; longitudinal grooves narrow and shallow on basal surface; a wide and deep groove forming a fold on the distal half of sutural margins ( Figs. 5C ; 17C , vf8).Valvifers IX covered by valvifers VIII, lateral margin convex ( Fig. 17D , vf9). Laterotergites IX not reaching the posterior margin of mediotergite VIII; lateral margin convex; setae on mid-basal portion of lateral margin and ventral surface ( Fig. 17C–D , la9). Thickening of vaginal intima barrel shaped, wider than long; proximal and distal margins concave, the distal one more sclerotized; extensive central area and elliptical areas on the laterals membranous ( Fig. 17D , vi). Vesicular area: anterior portion to the collar 1/5 of the posterior portion; median duct anterior to the collar with proximal widening ( Fig. 17D , mdp), median duct posterior to the collar with proximal and distal widening ( Fig. 17D , md). Distal ductus receptaculi 0.35 times the length of vesicular area posterior to the collar ( Fig. 17D , drd, drp). Pars intermedialis conical, broader distally ( Fig. 17D , pi); annular crests convergent, the proximal one half the diameter of distal one ( Fig. 17D , dac, pac). Capsula seminalis oval, longer than wide and with long laterobasal projection directed to the pars intermedialis ( Fig. 17D , cs, pr). Measurements: Table 5 .
Distribution . Argentina ( Formosa , Misiones) ( Fig. 6 ). Comments . The males of Ischnopelta confusa sp. n. ( Fig. 16A–B ) differ from other species by the the posterolateral angles of pygophore divided in two portions, being the ventral portion easily observed in posterior view ( Fig. 16C–E , pla, pr). The females can be identified by the presence of a fold following the distal half of the sutural margin of valvifers VIII ( Figs. 5C ; 17C , vf8). Although this feature also occurs in Ischnopelta magna sp. n. ( Figs. 5D ; 33C , vf8), I. confusa is shorter in size and with the projections of urosternite VII laminate and slightly oblique ( Fig. 17C , mpr), while in I. magna the projections are thickened and perpendicular to the urosternite surface ( Fig. 33C , mpr).