Rhiginia nicholsae Forthman & Gil-Santana, 2021

Forthman, Michael & Gil-Santana, Hélcio R., 2021, Two new species of Rhiginia Stål, 1859, with taxonomical notes on species in the “ cruciata-group ” of this genus and an updated key to the New World genera of Ectrichodiinae (Heteroptera, Reduviidae), Zootaxa 4952 (2), pp. 201-234 : 224-227

Rhiginia nicholsae Forthman & Gil-Santana , new species

( Figs. 71–83 )

Diagnosis. The male of this species can be distinguished from all other species of Rhiginia by the large body size, smooth and polished pronotal surface, uniformly dark brown-black legs, ovate head with a slightly elevated and dorsally rounded clypeus and strongly convex frons in lateral view, large eyes, large ocelli occupying about threefourths of ocellar tubercle and separated by a distance subequal to the diameter of an ocellus, anterior pronotal lobe distinctly concaved medially and approximately half the length of the posterior lobe, longitudinal sulcus on anterior pronotal lobe deep, transverse sulcus of the pronotum with a very deep paramedial punctation, proximal margin of the Cu+1A membranal cell about three times wider than the outer discal cell (M+Cu cell), and abdominal sternite II with slight medial transverse rugosity or with a medially rugose depression lacking distinct longitudinal ridges. Males of this species are similar to all other species in the cruciata -group that have a convex frons and uniformly dark brown to black legs. The new species is perhaps most similar to R. crudelis in general appearance (the new species was previously included in R. crudelis ), but it can be recognized by the larger body size, less ovate head shape in lateral view, larger eyes, more elevated clypeus, anterior pronotal lobe distinctly concaved medially (relatively straight in R. crudelis ) and approximately half the length of the posterior lobe (two-thirds the length in R. crudelis ), the transverse sulcus of the pronotum with a very deep paramedial punctation (absent in R. crudelis ), and the proximal margin of the Cu+1A membranal cell about three times wider than the outer discal cell (M+Cu cell) (twice the width in R. crudelis ). This species may also appear similar to R. crucifera , but it can be separated from this species by the large ocelli occupying three-fourths of the ocellar tubercle in lateral view (about half in R. crucifera ), the more prominently elevated ocellar tubercle, indiscernible anterolateral protuberances on the pronotum (discernible and rounded in R. crucifera ), and the wider proximal margin of the Cu+1A membranal cell (twice the width in R. crucifera ). Lastly, this species is also similar to R. bimaculata but differs by the more convex frons, distance between the ocelli subequal to the width of an ocellus (wider in R. bimaculata ), less elevated ocellar tubercle, deeper longitudinal sulcus on much of the anterior pronotal lobe (shallow near anterior margin in R. bimaculata ), deep paramedial punctation on the transverse sulcus (absent in R. bimaculata ), wider proximal margin of the Cu+1A membranal cell, and absence of longitudinal ridges on the medial region of sternite II.

Description. Male. MEASUREMENTS (in mm): total length, to tip of abdomen: 16.8–19.5, to tip of hemelytra: 17.2–18.8. Head (excluding neck): length: 2.7–3.1, height (maximum distance between upper and lower margin of the head): 1.7–1.9; length of anteocular portion (measured in lateral view): 1.3–1.4; length of postocular portion (measured in lateral view): 0.6–0.8; width across eyes: 2.5–2.7; minimum dorsal interocular distance (synthlipsis): 1.1–1.2; eye, dorsal view: width: 0.7–0.8, length: 1.0–1.1; distance between external margins of ocellar tubercle: 0.7–0.8; distance between ocelli: 0.20–0.25; maximum width of ocellus: 0.23–0.24; length of ocellar tubercle on midline: 0.5–0.6; maximum distance between antennal tubercles: 0.6–0.7; lengths of antennal segments: scape: 2.0–2.2, pedicel: 3.1–3.3, basiflagellomeres I: 1.6–1.8, II: 1.1–1.2, distiflagellomeres: I: 0.6–0.7, II: 0.5–0.6, III: 0.5, IV: 0.6–0.7; lengths of labial segments: II (first visible): 1.3–1.4, III: 1.3–1.4, IV: 0.6–0.7. Thorax: pronotum: anterior lobe: length: 0.9–1.1, maximum width: 3.3–3.7, posterior lobe: length 2.1–2.5, maximum width: 5.0–5.7; scutellum: length: 1.9–2.1, maximum width at base: 2.5–2.8. Fore legs: femur: length: 3.4–3.9, maximum width at midportion: 0.6–0.8; length of tibia: 3.8–4.6; length of spongy fossa: 0.6; length of tarsus: 1.3–1.5. Middle legs: femur: length: 3.4–3.9, maximum width at subapical portion: 0.6; length of tibia: 4.1–4.5; length of spongy fossa: 0.5–0.6; length of tarsus: 1.4–1.6. Hind legs: femur: length: 5.1–5.8, maximum width at subapical portion: 0.6–0.7; length of tibia; 6.4–6.9; length of tarsus: 2.0–2.1. Abdomen: length: 9.8–11.8, maximum width: 6.0–7.2. COLORATION ( Figs. 71–73 , 75–79 ): General coloration sanguineous with dark brown-black markings or regions. Head ( Figs. 71, 73 , 75–78 ): Dorsal surface mostly sanguineous, sometimes with dorsal surface adjacent to eyes yellow-orange; anterior margin of clypeus sometimes dark brown-black or yellow-orange; antennifers darkened apically and at inner and outer surfaces; ocellar tubercle concolorous with sanguineous head or slightly darker; lateral and ventral portions of head, including ventrolateral protuberance posterior to eye, dark brown-black; labrum dark brown-black, with apex lighter and more translucent; labial segments II and III dark brown-black, segment IV yellow-brown, at least apically; neck dorsally sanguineous or yellow-orange and dark brown-black laterally and ventrally; scape (except basal portion paler) and pedicel dark brown-black, basiflagellomere (except darker base) brown, distiflagellomeres (except darker base of first and apex of last segments) yellow-brown. Thorax ( Figs. 71– 72 , 75–77, 79 ): Pronotum mostly sanguineous, with the anterior and lateral margins of the anterior lobe and posterior margin of posterior lobe narrowly dark brown-black; medial longitudinal sulcus on anterior lobe often dark brown or black; transverse sulcus with two small paramedial dark brown-black spots; scutellum blackish, the apical scutellar processes sometimes dark red to brownish; pleurae and sterna mostly brownish to blackish brown; lateral portions of supracoxal lobes and medial portions of meso- and metasterna sometimes yellow-brown (medial portions can appear as two small paramedial spots); stridulitrum and posterior margins of prosternal process yellow-brown. Legs: Dark brown, almost black; coxae sometimes with a pair of faint brownish spots on anterior or external surface; tarsi brown. Hemelytra: Mostly blackish, with basal region orange or sanguineous, extending to basal fourth to fifth of costal margin; remainder of costal margin black or with irregular yellow-orangish markings throughout; irregular yellow-orangish marking at base of inner discal vein (1A vein), which is also pale basally (sometimes absent); another larger irregular yellow-orangish pale marking at medial region of hemelytron where the corium and membrane meet (sometimes absent), including the base of the M and Cu membranal veins. Abdomen ( Figs. 71–72 , 75–77 ): Mostly dark brown-black; outer portion of dorsal connexivum orange to sanguineous, ventrally entirely orange to sanguineous; sternites dark brown to blackish, except lateral areas adjacent to connexivum pale yellowbrown; sternites III–VII variably with medial pale yellow-brown patches (may be absent on some or all sternites and if present, patches can vary in size), which may join the lateral pale yellow-brown regions on sternites III and/or IV; sternites III and IV sometimes with small, irregular sublateral pale yellow-brown spots; area around spiracles concolorous with pale yellow-brown or faintly tinged red; sutures between sternites dark brown to blackish, except concolorous laterally with pale yellow-brown areas adjacent to connexivum; pygophore dark brown-black. VESTITURE ( Figs. 71–73 , 75–79 ): Body mostly glabrous. Head ( Figs. 71, 73 , 75–78 ): Few sparse, curved, somewhat stout brownish setae on ventrolateral portions of base of first visible labial segment; last labial segment with few scattered erect, thin, pale setae on its distal half. All antennal segments, except the glabrous mid-dorsal portion of scape, covered by very numerous short, oblique or adpressed thin setae, pale to yellow-brownish; scape, pedicel and basiflagellomeres also covered by numerous long, pale to yellow-brownish erect setae, which are approximately as long as (scape) or one and half or twice (pedicel and basiflagellomeres) the width of the respective segment; some additional few sparse longer erect straight brownish setae scattered on pedicel and flagellomeres, approximately two to three times as long as these segments, respectively. Thorax ( Figs. 71–72 , 75–77, 79 ): Pronotum and scutellum glabrous, except for a tuft of pale brownish setae on inner margin of posterior border of pronotum lateral to the scutellar base; pleurae and hemelytra glabrous, except the ventrolateral margin of the base of the hemelytron with spare, curved, oblique brownish setae; thoracic sterna mostly glabrous; borders of posterior prolongation of prosternum with numerous thin, longer, dark golden setae; some scattered pale silver to golden thin setae on postacetabular area of prosternum, laterally to the prosternal process; a patch of short, pale setae on medial walls of fore and middle coxal cavities. Legs: Coxae glabrous; trochanters with two rows of yellowish to golden, curved, short thin setae on ventral surface (specimens may appear to lack these), and a single, very long, erect seta on the basal ventral surface, papillae apparently absent; femora mostly glabrous; base of ventral surface of fore femora with a single elongated, somewhat curved, pale seta; all femora with few, small, mid-dorsal and lateral subapical curved brownish setae; basal half to three-fourths of fore and middle femora with a ventral fringe of minute, adpressed, thin, brownish setae; tibiae dorsally glabrous, distal one-third to half of sub-dorsal and lateral surfaces with short, straight, somewhat stout, suberect brownish to golden setae; fore and mid tibiae with similar vestiture on entire ventral surface (sometimes narrowly fringed basally), hind tibiae similar except glabrous basally; tarsi covered with numerous brownish to golden setae, which are longer on ventral surface. Abdomen ( Figs. 71–72 , 75–77 ): Glabrous. STRUCTURE ( Figs. 71–73 , 75–83 ): Integument mostly shiny and smooth. Head ( Figs. 71, 73 , 75–78 ): Ovate, slightly shorter than pronotum (excluding neck); anteocular portion about twice as long as postocular portion (excluding neck); ratio between the total length (including neck) and maximum width across eyes of the head: 1.23; minimum distance between eyes in dorsal view (synthlipsis) longer than the width of each eye; base of antennifers adjacent to the anterior margin of the eyes, their integument with moderately shallow transverse curved striations; between them, integument presenting several thin, shallow, subparallel transverse striations similar to those on antennifers; frons strongly convex; vertex not elevated; eyes prominent, rounded in dorsal view, suboval in lateral view; antennae inserted slightly closer to anterior margin of eyes than to the apex of the head; transverse sulcus anterior to the ocellar tubercle distinct but laterally becoming faint; ocellar tubercle prominent, undivided, ocelli rounded, distance between them subequal to the diameter of an ocellus, occupying about three-fourths of ocellar tubercle in lateral view; scape surpassing apex of head by more than its distal half, somewhat curved and enlarged towards apex, shorter than pedicel and longer than anteocular portion of head; pedicel almost straight, slightly curved at midportion; flagellum slender, divided into two basiflagellomere and four distiflagellomere pseudosegments; basiflagellomeres more slender than the pedicel and becoming gradually more slender apically, the first basiflagellomere longer than the second; distiflagellomeres thinner than basiflagellomeres, the first and last segments subequal in length and longer than the middle two distiflagellomeres; clypeus slightly wider at base, prominently and roundly elevated in lateral view; maxillary plate rugose; postocular region with a conspicuous, rounded ventrolateral protuberance behind posterior margin of eye; labium thick, length ratio between labial (visible) segments about 2.1:2.1:1.0; labial segment II (first visible) relatively straight distally, as long as segment III, its apex slightly anterior to the level of the anterior margin of eyes; labial segment III almost straight, its apex near the level of posterior limit of the head (excluding neck); labial segment IV shorter, tapering; ventral surface of head with scattered and irregular, thin, shallow (sometimes almost indiscernible) transverse impressions, somewhat more numerous and deeper at anterior portion near labial base and adjacent to ventrolateral protuberance of postocular region; constriction between postocular region and neck distinct. Thorax ( Figs. 71–72 , 75–77, 79 ): Pronotum smooth (sometimes appearing faintly wrinkled along transverse sulcus or posterior pronotal disc), shiny; collar thin; anterolateral protuberances indiscernible; anterior margin medially concaved; anterior lobe rounded on anterior margin, shorter and narrower than hind lobe; mid-longitudinal sulcus on anterior lobe thin and deep, except more shallow near anterior margin, interrupted before the median fovea by a shallow transverse ridge, with the remaining posterior part of the midlongitudinal sulcus represented by punctations, the two more anterior ones deeper and larger, followed by several progressively smaller and shallower punctations towards posterior margin, exceeding the distal half of the hind lobe where the sulcus becomes a very thin line that does not reaching the posterior margin; transverse sulcus distinct, shallow, interrupted paramedially to median fovea by a pair of short, curved shallow ridges, with a very deep paramedial punctation (where paramedial black spot on furrow exists); transverse sulcus continuing laterally on propleura, where it is formed by somewhat larger and deeper depressions, forming a somewhat curved lateral furrow that ends a short distance anteriorly to the posterior margin of propleura; posterolateral furrows of pronotum thin transverse striations, very shallow anteriorly but becoming prominent posteriorly before the posterior margin, and extends medially approximately to the level of lateral margin of scutellum; humeral angles rounded; posterior margin of pronotum somewhat prolonged posteriorly at the level of inner half of clavus, below a rugose area described above; scutellum sculptured, with a shallow, wrinkled, median depression; scutellar prongs moderately short, narrowly separated at the base and convergent towards their apices; supracoxal lobes of pro- and mesopleura somewhat prominent, those of metapleura not prominent; integument of anterior portion of propleura with few deep irregular punctations along the dorsal and anterior margins of the supracoxal lobe; integument of mesopleura slightly wrinkled, with small to moderately large punctations along the anterior and ventral margins and one to three larger, irregular depressions near the dorsal margin; metapleura coarsely rugose, with several linear, subparallel, irregular ridges, dorsal margin thickened and curved; prosternum wider on approximately anterior half in which there is a pair of short, rounded, lateral processes directed forward and narrowing posteriorly; a cylindrical median process on posterior half of prosternum, which surpasses fore coxae for a short distance, median portion occupied by stridulitrum and lateral margins with a rugose integument; postacetabular area of prosternum with smooth integument, except somewhat wrinkled medially towards prominent longitudinal ridges; between postacetabular area of prosternum and a pair of shallow depressions of mesosternum, a wide transverse ridge, which forms at its median portion a pair of anteriorly converging longitudinal ridges ending just posterior to apex of prosternal process; area between the longitudinal ridges adjacent to postacetabular area of prosternum with distinct transverse ridges; remainder of mesosternum mostly smooth; middle coxae bordered by elevated margins anteriorly and medially; medial area of mesosternum with a moderately elevated area that is subquadrate on the middle and posterior area of the mesosternum but that convergently narrows towards the anterior margin, integument marked by several shallow transverse lines that become more frequent anteriorly; metasternum convex, medially with a very shallow depression, integument with several shallow transverse lines, some of them incomplete or interrupted; area just anterior to hind coxa and posterior margin of metasternum somewhat elevated; fore coxae close, separated by a distance shorter than the width of each of them; middle and hind coxae distant from each other by a distance approximately 2 and 1.5 times the width of each coxa, respectively; all trochanters apparently without papillae; femora and tibiae generally slender; hind legs longer; fore and middle femora somewhat curved at distal third; middle and hind femora somewhat thickened subapically; hind femora straight; fore and middle femora ventrally with a very shallow and narrow medial crest ending near the apex; tibiae straight; fore tibiae conspicuously thicker at apex, in which the anterior margin is prominent, with a mesal comb; mid and hind tibiae slightly thicker at apex; spongy fossa on fore and middle tibiae small; tarsi slender, three-segmented; length ratio between tarsal segments is approximately the following: fore tarsus: 1:1.2:1.8, middle tarsus: 1:1.7:2.4 and hind tarsus: 1:2.4:2.7; hemelytra generally dull, moderately shiny at basal portions in which the coloration is sanguineous, its apex either far from posterior margin of last tergite by no more than 0.7 mm or surpassing the abdominal apex; inner discal cell of hemelytral membrane (Cu+1A cell) with veins subparallel; the proximal margin of the Cu+1A membranal cell about three times wider than the outer discal cell (M+Cu cell). Abdomen ( Figs. 71–72 , 75–77 ): Connexival segment II with posterolateral angle slightly prominent; dorsal connexival integument finely transversely wrinkled, much more prominent on the inner areas and becoming weakly visible on the outer margin (sometimes smooth); sternites shiny; sternite II narrower than the following segments, integument somewhat transversely rugose or irregularly rugose medially (but without distinct longitudinal ridges), somewhat depressed medially, separated from sternite III partially by canaliculae which are more prominent medially and sublaterally, becoming weakly prominent to absent at the lateral third to half near the connexivum; sternites III–VII mostly smooth, with fine, shallow transversely or irregular wrinkles laterally and sublaterally; intersternite furrows between sternites III–VI more prominent at lateral portion, without canaliculae, the furrow between sternites VI and VII somewhat more marked at median portion; spiracles on sternites II–VII elliptical, diagonally oriented in relation to the abdominal margin, approximately 0.15 mm in its maximum length, closer to the connexival suture by a distance approximately 1.3 times its maximum length, except about twice its maximum length on sternite II and 2.5 times on VII; on sternite II, the spiracle is located approximately at the midportion of basal half of the segment; on sternites III–VI, the spiracles are placed slightly anterior to the medial point between the intersegmental furrows; on sternite VII, the spiracle is closer to the level of the basal portion of pygophore than to the intersegmental furrow; segment VIII not visible externally, sclerotized on ventral portion, which becomes wider towards curved posterior margin; dorsal portion of segment VIII membranous and narrower; spiracles on dorsal margin of ventral portion. Male genitalia ( Figs. 80–83 ): Pygophore in ventral and lateral views: exposed portion of pygophore subpentagonal ( Figs. 72 , 76 ) and rounded, respectively; integument glabrous, smooth with few shallow wrinkles laterally, shiny; not pigmented in the ventral non-exposed portion; in dorsal view ( Fig. 80 ): between anterior and posterior genital openings, a well-sclerotized dorsal (transverse) bridge; membranous areas of posterior genital opening smooth; proctiger subrectangular, posterior margin slightly curved, with an apical row of straight setae; short medial process of pygophore sclerotized, subrectangular with dorsolateral margins rounded, apical margin almost straight, even more sclerotized ( Fig. 80 ). Parameres mildly exposed when genital capsule is in situ or in ventral view ( Figs. 72 , 80 ), their apices in contact in resting position; symmetrical, elongated, very curved at approximately middle third, basally very narrow with distal two-thirds become very wide and robust, with apex truncated and a short subapical blunt tubercle on dorsal and ventral margin, the latter almost imperceptible; mostly glabrous, with a few subapical very short straight setae on dorsal surface and small tuft of stouter, longer, straight setae between subapical tubercles. Phallus ( Figs. 81–83 ): articulatory apparatus with basal plate extension much shorter than basal plate, the latter with moderately short and curved basal plate arms connected by a narrow basal plate bridge; dorsal phallothecal sclerite symmetrical, enlarged to the apex, apex emarginated in center and somewhat sinuate laterally; mid-lateral portions with several grooves; lateral portions mostly smooth apically, wrinkled basally, moderately thickened, with an elongated dorso-lateral process prominently curved inwards and rounded at tip ( Figs. 81–83 ); endosomal struts converging towards apex of dorsal phallothecal sclerite, larger and subparallel at basal portion, fusing at the distal third with the dorsal phallothecal sclerite (the fused region appearing elongate ovoid); endosomal wall transversely striated on dorsal portion, ventrally smooth basally, becoming progressively spiny towards apex (spines minute); endosoma ( Fig. 83 ) with a median process at the apex and two subparallel and subrectangular regions leading to the median process weakly sclerotized; median process of endosoma formed by a pair of suboval, flat, sclerotized portions, narrowly united at its apex, with this point of union and surrounding parts even less sclerotized than most part of the process; endosomal wall with a small pair of subapical, lateral membranous lobe ( Fig. 83 ).

Distribution. Mexico.

Etymology. The new species is named in honor of the senior author’s (MF) grandmother, Brenda Joyce Nichols Forthman, who has always been greatly enthusiastic and supportive of his interests and pursuits in entomology.

Type material. Holotype: La Playa Escondida / 16 Km N. Sontecomapan / Veracruz, MEXICO / 2–9 August 1980 // Sierra de las Tuxtlas / Coll. at blacklight / L. G. Bezark & C. Y. Kitayama, Collectors (1 ♂) ( CSCA). Paratypes: Mexico / Coll. Signoret. // crudelis / det. Stal // Rhiginia / crudelis / Stål // B.C.A.Rhyn. II. / Ectrichodia / crudelis , / ♂ St // Syntypus / Rhiginia / crudelis Stål, 1862 / etik. Hecher 1996 / REDV. 107/1 (1 ♂) ( NHMW). La Playa Escondida / 16 Km N. Sontecomapan / Veracruz, MEXICO / 2–9 August 1980 // Sierra de las Tuxtlas / Coll. at blacklight / L. G. Bezark & C. Y. Kitayama, Collectors (3 ♂) ( CSCA).

Figures

FIGURES 71–74. Rhiginia crudelis Stål, 1862, syntype male (now treated as a paratype of R. nicholsae sp. nov.) deposited in NHMW (© Hemiptera Image Collection, Natural History Museum, Vienna). 71, dorsal view, scale bar 5 mm; 72, ventral view; 73, head, lateral view; 74, labels.

FIGURES 75–79. Rhiginia nicholsae Forthman & Gil-Santana, sp. nov., male holotype. 75–77, scale bar 2 mm; 75, dorsal view; 76, ventral view; 77, lateral view; 78 & 79, dorsal view; 78, head and anterior portion of fore lobe of pronotum, scale bar 0.5 mm; 79, posterior portion of head, pronotum and scutellum, scale bar 1 mm.

FIGURES 80–83. Rhiginia nicholsae Forthman & Gil-Santana, sp. nov., holotype, male genitalia, scale bar 0.5 mm. 80, pygophore and parameres, dorsal view; 81–83, phallus; 81 & 82, with endosoma not expanded; 81, dorsal view; 82, lateral view; 83, with endosoma expanded, dorsal view.