Revision of the genus Hellica Stål, 1867 and the description of three new genera of South American Lanopini (Hemiptera: Acanthosomatidae: Blaudusinae)

Three new genera are described, Epactiohellica based on a new species, E. farinai, Alloeohellica based on another new species A. faundezi, and Hellicoides based on the known species Hellica johni Froeschner. The genus Hellica is redescribed with two known species H. nitida Haglund and H. johnpolhemi Froeschner and one new species, H. kolla. Fifth nymphal instar of Hellicoides johni is described for the first time and fifth nymphal instar of H. nitida is redescribed. Distributional (biogeography, distributional patterns), ecological (coloration, host plants) and biological characters (nymphs, eggs) of these genera are discussed.


INTRODUCTION
The genus Hellica, currently belonging to the family Acanthosomatidae, subfamily Blaudusinae, tribe Lanopini, was described by Stål in 1868, in his "Bidrag till Hemipterernas Systematik" (Contributions to Hemiptera Systematics) in an extensive work containing only keys of the Pentatomoidea and a key to higher levels in the Coreoidea, new and known until that moment. He included Hellica within the "Acanthosomatidum", Pentatomidae (page 533). At that time, Stål did not designate a type species because he originally did not include any species in the genus. It was a barren genus. Haglund (1868) added a single species, nitida, to the genus, so this became the type species by subsequent monotypy. This type-species, Hellica nítida Haglund ( Fig. 1) was described based on, at least, one male specimen from "Amazonas" Brazil.
In 1884, Carlos Berg described Banasa pulchella based on six specimens, including both males and females from Uruguay. One of them is deposited in the Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (Bachmann, 1999) and three others are in the Museo de La Plata . The deposition of the remaining two syntypes is unknown. Berg does not make reference to the type-locality nor the number of nymphs that he briefly describes there, and they are probably also lost.
Under the name Banasa pulchella, Pennington (1920) cites the species for the first time for Buenos Aires province, Argentina. This species was also mentioned by  from Uruguay. Kumar (1974) briefly described the male of H. nitida (the female was not known at that time) in the context of a review of the acanthosomatid genera of the world. Rolston and Kumar (1974) Rev. Mus. Argentino Cienc. Nat.,n.s. 21(2): 2019 included this genus in their key to the genera of the Western Hemisphere. Banasa pulchella was finally synonymized with H. nítida by Thomas & Yonke (1990) and confirmed by Froeschner (2000). Concerning the taxonomy of Hellica, the last and most extensive study was the work of Froeschner (2000) in which he diagnosed and discussed H. nitida and described two new species: H. johni and H. johnpolhemi. More recently, Carpintero & De Biase, 2011 (list), 2015 (lists), Coscarón et al., 2015 (type-species), Di Iorio & Turienzo, 2015 (list), Dellapé, 2016 (list), Coscarón, 2017 (catalogue), mentioned this species. In this work, the authors propose to describe new taxa, redescribe known taxa and comment on previously unknown biological and ecological aspects of this "genus complex" (Hellica -Hellicoides -Epactiohellica -Alloeohellica). Not having yet a final phylogenetic analysis of the Lanopini (Carvajal et al., 2017), we will use this concept to refer to this group, which we consider to be a sister-group of genera, of the same lineage or clade, based on the following characters: small size, small and particular shape of ostiolar peri-treme, and as Kumar (1974) said: "Its distally broad and flattened anteclypeus is an uncommon feature in Acanthosomatidae". It is also to highlight its isolated geographical distribution, the different environment in which they are found, and the host plants that are quite different from the host plants of other South American acanthosomatid species. We will also discuss the differences that separate these new taxa from Hellica, and separate them from each other in the discussions of each of them.

MATERIALS AND METHODS
The photographs were taken with an Olympus DP 25 digital camera mounted on an Olympus SZF16 magnifying glass, using the Cell-Sense Standard program. The terminology concerning morphology and descriptive format follows Faúndez et al. (2014) for description of adults, and Martinez et al. (2003) for description of nymphs.
The measurements are given in millimeters (mm), giving number of specimens measured (n), minimum measure, maximum measure and in between, in parentheses, the mean. The studied material is deposited in the entomological collection of Museo Argentino de Ciencias Naturales "Bernardino Rivadavia" (MACN) of Buenos Aires city and entomological collection of the Mu-entomological collection of the Museo Municipal de Ciencias Naturales Lorenzo Scaglia (MMLS) of Mar del Plata (Buenos Aires province, Argentina). Fig. 1. Hellica nitida Haglund. The first author received this photograph for determination; the photographer's name was not provided. It comes from the "Reserva Natural Municipal del Pilar" (Buenos Aires). The authors thank the photographer who sent this beautiful photograph, regrettably for the moment remaining anonymous.
ing a very small angle (compared to Hellica nitida) (Fig. 2C). Dorsal surface covered with small, deep punctures, densely dispersed throughout its entire dorsal surface. Head (Fig. 5A). Anteclypeus densely punctured all along its length, extending slightly beyond anterior end of paraclypei; the latter flattened in their lateral margin; apically its mesial margin slightly overlapping anterior margin of an-teclypeus. Lateral margins of head slightly concave. Antennae short, all five segments of similar length; antennal segment I reaching near the middle of paraclypei; second segment reaching apex of clypeus. Bucculae wide with subparallel dorsoventral margins, covering nearly entire broadness of labial segment I, only ventral margin slightly visible, with a basal punctured line and other points beyond it. Labial segment I slightly surpassing posterior end of bucculae, labium extending to metacoxae. Head ventrally densely punctured. Thorax. Pronotum subquadrangular; cicatrices immaculate; lateral margins of pronotum straight, strongly carinate, more broadly on its anterior half; humeral angles rounded, a little produced. Scutellum longer than wide at its base, with an ivory callus on each side of base. Hemelytra not covering connexiva on its apical half; basal margin of membrane arising near apex of abdomen. Sternal area without median carina. Each ostiolar peritreme short, twisted, protruding, apically with spiniform process; evaporatoria densely punctured similarly as remainder of thoracic venter. Legs short; femora robust; each tibia flattened ventrally on its apical half, with tuft of spiniform, dark bristles near middle, this tuft may have a stridulatory function as observed in all other species of this genus-complex, and in many other genera of this family. Abdomen. Strongly, densely punctured except medially. Connexiva with very small, shallow punctures. Basi-abdominal spine present, short, apically rounded, reaching to middle of hind trochanters. Pendergrast's organs absent in females. In males, lateral margins of 7th sternites nearly straight; pygophore subrhomboid, posterior margin strongly convex, slightly prominent in mesial portion of posterior edge. Etymology. prefix Epaktios -from the Greek, meaning "coastal, from the coast" (Brown, 1985), because the four collection sites of this species were on the marine coast, and -hellica from the closely related genus Hellica. The gender is feminine. Discussion. Beyond its functional importance (Fischer, 2006;Tsai et al., 2015) the Pendergrast's organ is a character not yet used in the definition of Acanthosomatidae genera. Its form and relative location, and even its presence/absence are nonetheless constant and very characteristic of each genus. From this study, the authors present this character as useful and complementary to other characters for the discernment of the South American genera of this family. Epactiohellica differs from the closely related genus Hellica by its smaller size, the density of the punctures on its body, the shorter antennal segments and legs, the wider bucculae, and by the absence of Pendergrast's organs in the female (Fig.  3). In addition to the above, it differs from Hellicoides by the flattened (not concave) paraclypei. Head. (Fig. 5A). Wider than long (0.2 times), entirely covered by dense, dark brown punctures, which are homogeneously distributed throughout except around eyes and in two short, smooth, longitudinal bands between ocelli. Antennal segment II very short, but longer than third, and subequal in length to fourth; fifth segment longer. Eyes small, prominent, rounded laterally, their mesial and basal margins straight, junctures between margins angulate; ocelli rounded, larger than surface punctures, not contiguous with pronotum. Posterior margin of bucculae at level with middle of eyes; apex of labium reaching mesosternum; labial segment II longest, third segment shorter than second but slightly longer than fourth segment; third and fourth segments smaller in diameter than observed in species of Hellica. Thorax. Pronotum two times wider than long; dorsal surface covered by dense, strong, brown punctures; calli, anterior and posterior margins of pronotal collar smooth. Scutellum apically narrow, with uniform, disperse, brown punctures, except along sublateral margins and within a median line, which are smooth; a small, ivory callus in each humeral angle, associated with a fovea (on each side) with dark brown punctures. Hemelytra slightly convex; clavi and coria densely punctured; membrane hyaline, each with a median brown stripe, and a few weak longitudinal veins. Thoracic sterna covered with dense brown punctures, interspersed with a few smooth patches. Legs concolorous with body, tibiae and tarsi with broad, suberect, golden hairs on their inner margins, becoming more dense towards their apical halves; second tarsal segment longer than first.
Abdomen. Connexival segments concolorous with body, punctured. Genitalia: Pygophore (Fig. 2D) slightly punctured along lateral margins, ventral rim slightly concave medially, with two tufts of golden, erect hairs, which are visible in dorsal and ventral views; parameres narrow, elongate, with basal portions laterally black, extremely curved, touching apices of both parameres; apices of parameres sharpened, apically pointing forward.  Diagnosis. This genus is characterized by the long hairs on the labium and legs, by the large eyes, and by the elongate hemelytra, which exceeds beyond the apex of the abdomen. Description. Oval elongate, medium-sized species; in lateral view, pronotum (without lateral carina) and head forming medial angle with respect to dorsal profile (Fig. 4B). Dorsal surface covered with narrow, scattered punctures. Head (Fig. 5B). Short, wide; lateral margins not flattened; head ventrally sparsely punctured. Anteclypeus with few punctures on basal third, extending well beyond apices of paraclypei, which are apically narrow and lateral margins curved, and mesial margins opening towards apices, causing anteclypeus to be twice as wide apically than basally. Antennae long, surpassing base of pronotum (when stretched posteriorly); segment I reaching, or sometimes slightly surpassing apex of head; segment II slightly longer than III; segments II and III longer than segments IV and V. Bucculae narrow, covering less than half the broadness of labial segment I, with a few basal punctures, appearing smooth. Labium short, only reaching base of mesosternum; covered by erect hairs which are longer than broadness of labial segments, aligned along its ventral margin (Fig. 4E); labial segments I and II narrow in diameter, segment III slightly enlarged in diameter, segment IV less enlarged.
Thorax. Lateral margins of pronotum straight, not carinate. Scutellum 0.2 times wider along base than medial length. Ostiolar peritremes small, twisted, protruding, each with apical spiniform process. Legs with sparse, long, erect hairs on ventral surfaces (Fig. 4D); femora broader than tibiae, but not particularly short or robust; tibiae not flattened ventrally on apical halves; tarsomere I much shorter than segment II, also with long hairs.
Abdomen. Basi-abdominal spine present, somewhat more elongate than in other genera of this complex, reaching bases of posterior coxae, apically rounded. Extreme margins of connexival segments smooth. In males, lateral margins of 7th sternites slightly curved; pygophore with setae along posterior margin, grouped in loose patches. Etymology. prefix Alloios -from the Greek, meaning "of another kind, different" (Brown, 1985) and -hellica, from Hellica, the first described genus of this group. The gender is feminine. Discussion. Alloeohellica gen. nov. differs from the closely related genus Hellica by the shorter and wider head, the larger eyes, the longer antennae, the erect pilosity on the ventral surfaces of labium and legs, which is greater in length than the width of the segments (much more so than in the other species of this complex), and by the particular shape of pygophore and the apically spatulate parameres.  Head. (Fig. 5B). Wider than long (0.5 times), entirely covered with sparse, dark-brown punctures. Eyes large, prominent, rounded laterally, their mesial and basal margins straight, juncture between these margins angulate; ocelli rounded, larger than surface punctures, nearly contiguous with pronotum. Posterior margins of bucculae ending near level with middle of eyes. Labium reaching base of mesosternum; labial segment I short, not surpassing posterior margins of bucculae, second segment longest, third segment shorter than second, but slightly longer than fourth.
Thorax. Pronotum subquadrangular, two and a half times wider than long, lateral margins rounded, without lateral carinae; dorsal surface covered by sparse, strong, brown punctures, anterior lobe more sparsely punctate. Scutellum apically narrow, with uniform, disperse, brown punctures, except along sublateral margins which are smooth, and two small, ivory calli one in each humeral angle. Hemelytra slightly convex, sublinear; clavi densely punctate; coria sparsely punctate; membranes long, extending far beyond apex of abdomen, hyaline with a few weak longitudinal veins. Thoracic sterna covered with dense brown punctures interspersed with some smooth patches. Legs concolorous with body, tibiae and tarsi with broad, suberect, golden hairs on their inner margins, becoming more dense towards their apical halves.

Female: Unknown.
Etymology. The specific name is dedicated to Dr. Eduardo I. Faúndez in recognition of his contributions towards our studies of South American Acanthosomatidae. Distribution. ARGENTINA: Buenos Aires (Fig. 7). Host plant. Unknown. Discussion. Unfortunately, the only known specimen is dotted with a substance that complicates seeing some details. On the other hand, those characters important for its separation from other related genera and species are visible.

Hellicoides new genus (Fig. 6)
Type species: Hellica johni (Froeschner, 2000), by present designation. Diagnosis. This genus is characterized by having the paraclypei marginally concave and subequal in length to anteclypeus, antennal segment II always longer than III and in females, and the Pendergrast's organ vestigial. Description. Oval, medium-sized species with paraclypei depressed, curved anteriorly. Dorsal surface covered with strong, deep, dense punctures. Head (Fig. 5D). Lateral margins of head flattened; head sparsely punctate ventrally. Anteclypeus extending apically almost at the same level as the paraclypei with many punctures only on the basal half; the latter depressed, concave, subapically flattened along their lateral margins; apically, their mesial margins slightly overlapping lateral margins of anteclypeus anteriorly; anteclypeus approximately of uniform width for its entire length. Antennae long, segment I not reaching apex of head, segment II always longer than III; segments II + III together longer than IV or V. Bucculae narrow, covering less than half the broadness of labial segment I, with some basal, shallow punctures, appearing smooth. Labium short, only reaching base of mesosternum; labial segments I and II narrow in diameter, segment III not particularly enlarged in diameter, segment IV less enlarged.
Thorax. Lateral margins of pronotum straight, without well-developed carinae. (Fig. 6C). Scutellum with ratio of medial length/basal width subequal. Ostiolar peritremes small, twisted, protruding, each with apical spiniform process. Legs with femora broader in diameter than tibiae, but not particularly short or robust; tibiae not flattened ventrally on their apical halves; tarsomere I much shorter than II.
Abdomen. Strongly but sparsely punctured, except in a medial, longitudinal band. Basiabdominal spine present, short, apically rounded, reaching to middle of hind trochanters. Extreme margins of connexival segments smooth. Pendergrast's organs present, but only slightly developed, restricted to anterior half of sternite VII (last pregenital segment), scarcely darker than rest of ventrite, glabrous, with punctures inside. In males, lateral margins of 7th sternite slightly curved; pygophore subrhomboid. Etymology. Suffix -oides from the Greek, meaning "like, resembling, having the form of" (Brown, 1985) after the prefix hellic-from the closely related genus Hellica. The gender is feminine. Discussion. The more elongate habitus, the distinctive shape of the anteclypeus and the paraclypei (concave and of subequal length), characters already highlighted by Froeschner (2000), along with the relative lengths of antennal segments II and III (II longer than III), and the characteristics of Pendergrast's organs, lead us to propose that this species is not congeneric with Hellica. ish, transverse, well-delimited "H" on anterior lobe. Scutellum whitish with two light-brown blotches along base, and a light brown longitudinal medial band. A small, dark-brown longitudinal band in centre of each corium, which is continued as a long, sublateral stripe on each membrane. Ventral surfaces yellowish-brown, with a tapering, longitudinal, fuscous area of varying width on each side; some specimens may have abdominal venter dark brown, except for abruptly-delimited yellow lateral margins, as in the other members of the genus-complex.
Head. (Fig. 5D). Wider than long (0.3 times), entirely covered by dense dark-brown punctures, which are distributed uniformly throughout, except for smooth, impunctate bands on internal margins between eyes and ocelli. Eyes small, prominent, rounded laterally, their mesial and basal margins straight, the juncture angulate.
Ocelli rounded, larger than surface punctures, not contiguous with pronotum. Posterior margins of bucculae ending at level near middle of eyes. Labial segment I slightly surpassing posterior margins of bucculae, second segment longest, third segment shorter than second, but slightly longer than fourth; third and fourth segments smaller in diameter than observed in species of Hellica. Thorax. Pronotum subquadrangular, more than two times wider than long; humeral angles rounded; dorsal surface covered by dense, strong, brown punctures, except for characteristic H-shaped spot of anterior pronotal lobe, and two sublateral bands and extreme base near scutellum, smooth. Scutellum apically narrow, with a few disperse, brown punctures medially, and two small ivory calli, one on each humeral angle. Hemelytra slightly convex; clavi densely punctured; coria densely punctate; hemelytral membranes hyaline, each with a median brown stripe, and a few weak longitudinal veins. Thoracic sterna covered with dense, brown punctures interspersed with some smooth patches. Legs concolorous with body; tibiae and tarsi with broad, suberect, golden hairs on their inner margins, becoming much more dense towards their apical halves.

Discussion. See under genus.
Nymphs. There is only one nymph I and two nymphs V (see studied material). We believe, however, that it is interesting to give these measurements and descriptions since, even though we do not have enough material to see the variability, this is the first study that is made of the nymphs of this species. Fifth instar. (Fig. 12D) dark-brown submedian longitudinal stripes, each with two medial light-brown circles; sparse and homogeneously punctured, subglabrous. Mesoand metatergum light brown, with dark brown stripes; punctured, subglabrous. Wing pads with similar stripes and punctures. Legs pale brown, a few short setae on femora and basal halves of tibiae, becoming more abundant, long on apical halves of tibiae and tarsi. Abdomen: yellowish brown with intersegmental margins reddish, with short lines parallel to them of same color; densely punctured near lateral margins, along intersegmental sutures, and around scent glands, except area between scent glands; scent glands between segments III-IV, IV-V, V-VI and VI-VII: the first divided into two, more separated from remaining scent glands; second not divided, entire, somewhat wider than third, and last very small, non-functional. Abdomen with similar red lines as in dorsal view; punctures only along lateral margins; spiracles 2 to 8 sublateral; no visible setae. Ventrally pale brown, with two sublateral dark-brown stripes on pleural regions. Discussion. Due to the distinct differences in shape, measurements, and coloration observed between the fifth instar nymphs of this species and Hellica nitida, we speculate that the immature forms present characters of high taxonomic value and as such, future projects on this family should include the study of immature forms. Description. Broadly oval, small to mediumsized species; in lateral view, margin of hemelytra and lateral margin of pronotum showing a wellmarked angle (Fig. 8C). Dorsal surface covered with strong, deep and sparse punctures. Head (Fig. 5C). Lateral margins of head flattened; head sparsely punctured ventrally. Anteclypeus with some punctures on the basal quarter of its length, length extending well beyond apices of paraclypei (differing from illustrations in Froeschner, 2000); paraclypei with mesial margins divergent towards apices, allowing anteclypeus to be twice as wide apically than basally. Antennae long, segment I not reaching apex of the head; segment II always equal to or shorter than III (also differing from illustrations in Froeschner 2000); segments IV and V of equal length or longer than segments II and III taken together. Bucculae narrow, concealing less than half the broadness of labial segment I, with only a basal punctured line; labial segments I and II smaller in diameter; segment III particularly enlarged in diameter; segment IV less enlarged.
Discussion. According to Froeschner (2000): "Among those (previously known) genera of the tribe Lanopini Kumar with juga not surpassing the tylus and humeri not projecting beyond the outline of the costa, Hellica is recognizable by the very short peritreme that is virtually no longer than wide". In addition to this definition, the genus Hellica differs from the rest of the Lanopini, by its geographical distribution. The discovery of new taxa with virtually the same morphological characters, and with similar distributions leads us to believe that a natural group of species has evolved in this region. This group of species, representing several different genera, is considered here to be a "genus-complex." To date, there has been no thorough phylogenetic analysis of the tribe, but it appears that this complex of genera has diversified at these latitudes, including particular morphological adaptations, which has led us to group them into at least four different, but closely related genera.  (Pennington, 1920); Santa Fe (Bosq, 1937); Córdoba, Misiones, Tucumán (Pirán, 1948); Corrientes ; Formosa (Froeschner, 1999); Martín García Island . BRAZIL: Amazonas (?), Santa Catarina (Haglund, 1868); Rio Grande do Sul, Paraná . URUGUAY: Colonia (Berg, 1884). New records. ARGENTINA: Chaco, Entre Ríos, Santiago del Estero (Fig. 10)  . Discussion. This species differs from H. johnpolhemi by its smaller size, by the coloration of the scutellum, and by the fact that the two species seem to prefer different habitats. That is, H. johnpolhemi has always been found above 1500 m asl, while H. nitida appears to be only found at lower elevations in the plain. From H. kolla sp. nov., it differs by its general coloration, by having broader parameres, and it is also usually found at higher altitudes, similar to H. johnpolhemi.

Hellica nitida
Nymphs. Fifth instar. (Fig. 12A, B)  of femora and on basal halves of tibiae, becoming more abundant on apical halves of tibiae and tarsi.
Abdomen. greenish (yellowish-brown in dried specimens) with lateral halves greenish, area surrounding scent glands yellowish-brown, scent glands, themselves, reddish brown; ventrally densely punctured towards the lateral margins, area surrounding scent glands smooth (Fig.  12C), each scent glands surrounded by a row of punctures, with more punctures between them; those between segments III-IV, IV-V, V-VI and VI-VII: the first divided into two parts and more separated from the following; second not divided, entire, somewhat wider than third, and last very small, non-functional. Ventrally greenish brown. Abdominal venter only punctured along lateral margins; spiracles 2 to 8 sublateral; no visible setae.  Larger species, between 6 and 7.2 mm long. Dorsally pale brown with a narrow yellowish band on each exocorium. Head yellowish with a brown central stripe and a fuscous band in centre near basal margin. Scutellum yellowish and as stated by Froeschner (2000): "this species can be readily recognized by the presence of two (usually joined) black blotches at base of scutellum". Pronotum yellowish, basal lobe, excepting lateral margins, darker. Calli pale brown with a dark spot on each of them.

Hellica johnpolhemi
Head. Thirty percent wider than long, entirely covered with dark-brown punctures, which are uniformly sparsely distributed throughout except around eyes and two short, smooth, longitudinal stripes between ocelli. Thorax. Pronotum more than two times wider than long, laterally without carinae (Fig. 9B); dorsal surface covered by strong, brown punctures; calli and anterior and posterior margins of pronotal collar, smooth. Scutellum wider than long, apically narrow, with uniform, disperse, brown punctures, except on basal half of sublateral margins. Hemelytra slightly convex; coria sparsely punctured. Thoracic sterna covered with dense, brown punctures interspersed with some smooth patches. Legs pale yellowish, second tarsal segment longer than first.
Abdomen. Connexival segments in dorsal and ventral views pale yellowish. Genitalia: According to Froeschner (2000): "the posterolateral margin of the third genital plate is convexly rounded, covering the lateral end of the second genital plate and slightly overlapping the posterior lateral angle of the basal genital plate" (Fig. 9C). Male: Descriptive characters apply to both sexes (according to Froeschner, 2000). Genitalia: "the apical margin of the genital capsule is broadly and shallowly bilobed in the middle third; the posterolateral margin of the third genital plate is convexly rounded, covering the lateral end of the second genital plate and slightly overlapping the posterior lateral angle of the basal genital plate" (Froeschner, 2000). Distribution. BOLIVIA: Quime (3048 msnm); ARGENTINA: Formosa (Froeschner, 2000) (see under Discussion); Tucumán, Jujuy . New record. ARGENTINA: Salta (Fig. 10). Host plant. Unknown. Discussion. In the six specimens we have examined, the scutellum has a long, basal, black blotch. This character, its large size, and the characters of the genitalia, together with the fact that this species is found only at altitudes greater than 1500 m asl, differentiates this species from the other species of the genus. We have noted the presence of two blotches in all other species of the genus. Froeschner (2000) stated:"Because there were no males and females bearing the same locality data, there is a possibility they are improperly associated here…" Based on this, and considering that the Formosa specimen is geographically distant from the rest of the known material of this species (see  and the current work), we consider that this specimen, which we have not examined, probably belong to H. nitida. Froeschner's reference (2000: 169) to "Brazil: Tafe del Valle, Quebradada la Angostura" refers to Tafí del Valle, Quebrada la Angostura, Tucumán, Argentina (see also . Hellica kolla sp. nov. (Fig. 11 Head. Wider than long (0.3 times), entirely covered by sparse, dark-brown punctures, which are more abundant between eyes. Antennal segment I nearly reaching apices of paraclypei, second segment slightly shorter than or subequal to third segment, and second and third segments taken together much shorter than fourth and fifth segments. Eyes small, slightly prominent, rounded laterally, their mesial and basal margins straight, their juncture angulate; ocelli rounded, larger than surface punctures, nearly contiguous with pronotum. Posterior margins of bucculae ending at level near centre of eyes. Labium reaching middle of mesosternum; labial segment I short, slightly surpassing posterior margins of bucculae, second segment longest, third segment shorter than second but slightly longer than fourth; third and fourth segments broadened. Thorax. Pronotum subquadrangular, two and a half times wider than long, laterally without carinae (Fig. 11B), humeral angles rounded; dorsal surface covered by sparse, strong, brown punctures; anterior and posterior margins of calli, and pronotal collar, smooth. Scutellum 20% wider than long, apically narrow, with uniform, disperse, brown punctures, except smooth sublateral margins and two small, ivory calli, one in each humeral angle. Hemelytra quite convex; clavi and coria densely punctured; membranes hyaline with a few weak, longitudinal veins. Thoracic sterna covered with dense brown punctures interspersed with some smooth patches. Legs concolorous with body, tibiae and tarsi with broad, suberect, golden hairs on their inner margins becoming more dense on their apical halves; second tarsal segment longer than first.
Abdomen. Connexival segments in dorsal and ventral views concolorous with body. Genitalia: Pygophore hairy along its margins, centrally punctured; ventral rim straight medially. Parameres narrow, quite curved, with basal portions apically black, gently curved; apex of each paramere somewhat rounded, not sharpened and touching each other (Fig. 11E).  (Fig. 11C). Genitalia: First gonocoxae elongate, wide, surfaces rugose; second gonocoxae small, each gonocoxite nearly triangular posteriorly; paratergites 8 narrow, short, widely rounded posteriorly; paratergites 9 subtriangular (Fig. 11D). Etymology. The specific name comes from "kolla" the ethnic group that inhabits the area where this species was found. Distribution. ARGENTINA: Salta (Fig. 10). Host plant. Unknown. Discussion. This species differs from H. johnpolhemi, its closest relative, by its smaller size and different coloration, especially by the presence of two dark spots on the base of the scutellum (in H. johnpolhemi, there is a continuous dark band on the base of the scutellum). Regarding the presence or absence of the Pendergrast's organs, we provide a transcription of the text published by Fischer (2006), in which he comments on the relationship of its absence with the maternal care observed in the genus Elasmucha Stål; similar inferences might be possible for other related genera lacking this organ: "Pendergrast's organs are totally absent in species of the genera Aga-medes, Bebaeus, Catadipson, Elasmucha, Ibocoris, Mahea, Phorbanta, Proctophantasta, and Uhlunga. The absence of Pendergrast's organs in Elasmucha-species correlates with the presence of maternal care, which the females of these species perform. The females guard their eggs and nymphs. Catadipson, Ibocoris, Proctophantasta, and Uhlunga are closely related to Elasmucha." Tsai et al. (2015) also stated: "Considering the strong correlation between a morphological and a behavioral trait, maternal care can be expected to occur in other genera of the family." Considering these studies, we believe that members of the genus Epactiohellica gen. nov. may exhibit maternal care, something that we have not been able to corroborate yet, as we did not find populations in our field trips during the summer 2018-19.

Some biological and ecological aspects about this complex
Coloration. Species of this complex have a cryptic homochromy; that is, their coloration allows them to be camouflaged in the environment. Selective pressure for this may be due to the fact that members of the Cyperaceae develop in full sun exposure, a habitat which may make these bugs more vulnerable to predators (Fig.  13A, B, D).
The eggs of Hellicoides johni were deposited on the involucral leaf of the inflorescence of Scirpus giganteus. The number of eggs in the observed egg mass was 14, of which eight hatched (the white ones) and the rest varied in coloration from brown to light brown, with a single silver coloured egg (Fig. 13E).
Regarding the observations on eggs of Ditomotarsus hyadesi Signoret made by Carvajal & Faúndez (2015), we agree that H. johni eggs may have different colours similar to D. hyadesi, but they say: "One female can only lay eggs of one colour during her lifetime." We observed more than one colour in the same egg mass. Another interesting coincidence is that they also state: "Collecting the eggs was a difficult work because they jump with the contact of the paint brush." We took pictures of the eggs in the field, and then brought the plant samples to the laboratory. We were unable to find the egg masses in the laboratory; this may be because they "jumped" from the Scirpus involucral leaf before we could secure them.

Previous knowledge and hypothesis.
One of the primary objectives of this study was to determine the host plants of the species of this genus-complex. South American genera and species of Acanthosomatidae are distributed mostly along the Andes Mountains and south of the Andean Region (Morrone, 2001) where they have become most diversified. In this region, acanthosomatids are nearly always associated with the Nothofagus (Nothofagaceae: Fagales) or at least with the forests of Nothofagus. Genera and species of the Hellica complex are distributed mostly in southeastern South America, in the Neotropical Region, "Chaqueña" Subregion, Chaco and Pampa provinces (Morrone, 2001); Nothofagus is not found in this region.
In accord with this information, in the summer of 2018-19, we began to survey potential host plants for the acanthosomatid species known to occur in the argentine province of Buenos Aires. The authors had already collected several of these species (including Hellica kolla sp. nov. from northern Argentina). It became apparent that the collected specimens were always found near water: Hellicoides johni on the banks of the Parana and De La Plata rivers, Epactiohellica farinai on the edge of the Atlantic Sea, Alloeohellica faundezi on the edge of the De Los Padres lagoon, at the base of the De Los Padres hills (near Mar del Plata) and Hellica nitida, the most widely distributed species, always near watercourses or lagoons in the eastern part of Argentina, Uruguay and southern Brazil.
In addition, the first author recalled having collected species of Hellica on Cyperaceae of the type with "spikelets arranged in umbels" (Cabrera & Zardini, 1978), probably belonging in either Cyperus and/or Scirpus. The particular coloration of the species of both acanthosomatid genera, which mimics perfectly with the inflorescences of the Cyperaceae (Figs. 13A and D), supported the hypothesis that they might be found on these plants.
Interestingly, there are almost never long series of specimens of the studied acanthosomatid species; that is, they are not found in large numbers in collections (see Haglund 1868;Berg 1884;Mendonça Jr et al. 2009;. Despite having been found many times and in many localities, species of this generacomplex have never been collected abundantly, perhaps because they are probably found in small populations in nature. In addition, nymphs had not been mentioned of any species of Hellica, except those briefly described by Berg (1884).

Results of our research.
After reviewing the above information from the literature, the authors suspected that some, or perhaps all, species in the Hellica complex may be found on species in the family Cyperaceae.
Another noteworthy aspect of the field observations is the monospecificity of the studied species of Hellica's complex, which is probably a common characteristic of all their species. To corroborate this theory we must mention that in the species that we have been able to observe (H. nitida and H. johni) in natural populations, they always were found cohabiting adults and nymphs, and their eggs were also found with them. It is also noteworthy that in this study, the populations per plant (inflorescence) contained from three to seven specimens per plant, depending on the species considered.
In the case of Hellica nitida, the most widely distributed species of this complex, specimens are nearly always found on Cyperus eragrostis eragrostis (Cyperaceae) which is very common in northern Buenos Aires. It is adventitious, and can easily be found in the city. It is very common in or near the sidewalks of the cities around the city of Buenos Aires. Hellica nitida, however, is never found on this plant in the city. We believe this is due to the Cyperus populations in the city grows especially in the sidewalks of the streets and in the corners, where there is more humidity. There, they are annually cut. It appears that Hellica nitida, for development, requires natural populations of Cyperus eragrostis eragrostis, populations that are present year after year without human interference.
As for Scirpus giganteus (Cyperaceae) on which Hellicoides johni was found, it has a more restricted distribution being confined to the system of the Paraná (and Paraguay)-Uruguay-de la Plata rivers. For this reason, this acanthosomatid has only been found on the banks of these rivers.
Superimposing the known distributions of the bugs with that known for their host plant, it can be seen that their distributions coincide, and further localities can be identified where the bugs may potentially occur. Furthermore, by an- alyzing the distributions of all species of Cyperaceae known from the province of Buenos Aires, we were able to hypothesize that Hellicoides johni probably occurred on Scirpus giganteus, a fact which was corroborated from the field work in this study.
It may be of interest to the reader to review some characteristics of the host plants. The following has been extracted from the web page of the Darwinion Institute, "Flora del Conosur" (http://www2.darwin.edu.ar/Proyectos/FloraArgentina/DetalleEspecie.asp?)