Review of the Neotropical genus Rhyncholepta with descriptions of three new species-group taxa (Hemiptera, Heteroptera, Pentatomidae)

Abstract The genus Rhyncholepta Bergroth, 1911 (Hemiptera: Heteroptera: Pentatomidae: Pentatominae: Chlorocorini) is redescribed and five species-group taxa are recognized, keyed, their diagnostic characters illustrated, and the distribution reviewed. Among the five taxa, two species and one subspecies are recognized as new: Rhyncholeptagrandicallosagrandicallosa Bergroth, 1911 (Brazil, Ecuador, French Guiana, Guyana, Peru, Suriname), Rhyncholeptagrandicallosacentroamericanasubsp. n. (Belize, Costa Rica, Guatemala, Mexico, Panama), Rhyncholeptahenryisp. n. (French Guiana), Rhyncholeptameinanderi Becker & Grazia-Vieira, 1971 (Bolivia, Brazil, Ecuador, Peru), and Rhyncholeptawheelerisp. n. (Guyana). The structure of the male genital capsule was found to be the only reliable character for identifying species-group taxa. For this reason, a simultaneous application has been submitted to the International Commission on Zoological Nomenclature to set aside the non-informative female lectotype of Rhyncholeptagrandicallosagrandicallosa and replace it with the male neotype suggested herein. Based on the available label data and our field experience, most of the specimens were collected by various types of light traps in or near dense forests. Adults can be collected throughout the year.


Introduction
described a new pentatomid genus, Rhyncholepta Bergroth, 1911, which included the new species Rhyncholepta grandicallosa Bergroth, 1911, from French Guiana. He originally placed Rhyncholepta in the subfamily Arminae (currently valid name Asopinae) because of a habitus superficially similar to that of members of the asopine genera Apateticus Dallas, 1851 and Podisus Herrich-Schaeffer, 1851, and also listed several structural differences including the eponymous slender rostrum (Bergroth 1911(Bergroth , 1914, which actually excludes it from that subfamily. Bergroth (1914) provided an excellent color painting of Rh. grandicallosa. The genus Rhyncholepta was not mentioned during the following decades until Pirán (1956), who reported a male from Bolivia, provided a line drawing of the abdominal apex and the genital capsule in ventral view, and erroneously designated it as the allotype of Rh. grandicallosa. Becker and Grazia-Vieira (1971) first studied this genus in detail including descriptions of the external and internal genitalia of both sexes and distinguished two species, Rh. grandicallosa (interpretation based on examination of the female primary type) and a new species, Rh. meinanderi Becker & Grazia-Vieira, 1971 (= Rh. grandicallosa sensu Pirán). They transferred Rhyncholepta from the Asopinae to the Pentatominae, tribe Pentatomini, indicating that the genus is probably related to Loxa Amyot & Serville, 1843, and Fecelia Stål, 1872(cf. Thomas 1992. Despite the transfer of Rhyncholepta to the Pentatominae, the genus was omitted in keys to the pentatomine genera of the New World (cf. Rolston andMcDonald 1981, 1984;Rolston et al 1980). Rhyncholepta since has been included in a generic key by Torres Gutiérrez (2005), and several authors have provided new distributional records or checklists from Honduras, Panama, Colombia, Venezuela, Brazil and Peru (Grazia 1984, Froeschner 1999, Arismendi and Thomas 2003, Castro-Huertas et al. 2015, Cambra et al. 2018, Rider et al. 2018, Silva et al. 2018. Greve et al. (2013) included Rh. grandicallosa, along with Loxa deducta Walker, 1867 and Mayrinia curvidens (Mayr, 1864), as out-groups in their cladistic analysis of Chloropepla Stål, 1867, considering them closely related (based mainly on the presence of the hypandrium on the ventral wall of the genital capsule). The hypothesized relationship of Rhyncholepta with the allied genera was formalized by the description of the tribe Chlorocorini Rider, Greve, Schwertner & Grazia, 2018(in Rider et al. 2018, including Arvelius Spinola, 1837, Chlorocoris Spinola, 1837 (with 3 subgenera: Arawacoris Thomas, 1998, Chlorocoris, andMonochrocerus Stål, 1872), Chloropepla, Eludocoris Thomas, 1992, Fecelia, Loxa, andMayrinia Horváth, 1925. Our examination of representative material of 1125 specimens of Rhyncholepta collected in the last few decades revealed a very complicated situation in this genus. We distinguish five species-group taxa based on the structure of the genital capsule of the male. The existence of two morphologically nearly identical species syntopic in the area of French Guiana (type locality of Rh. grandicallosa) required reinterpretation of the taxon Rh. grandicallosa. Females, however, are insufficiently informative to serve this purpose; therefore, we selected a male candidate neotype for Rh. grandicallosa grandicallosa Bergroth, 1911, and we are asking the International Commission on Zoological Nomenclature to set aside the non-informative female lectotype (Kment et al., submitted).

Materials and methods
width, dorsal surface of head flat. Mandibular plates continually narrowing from eyes toward apices, lateral margins slightly concave at midlength and slightly convex in anterior half, surpassing clypeus by about basal width of clypeus but not meeting each other, leaving narrow, V-shaped notch in front of clypeus ( Figure 9; width of notch varies intraspecifically). Clypeus sharply narrowing in anterior half, apically free but slightly depressed compared to mandibular plates. Ocelli large, posteromedial to compound eyes, distance between ocellus and adjacent compound eye about diameter of ocellus, distance between ocelli about three diameters (Figure 9). Antenniferous tubercles (Figs 9-11) short, completely visible in dorsal view, without spine or tubercle laterally. Antennae long, surpassing apex of scutellum when folded backwards ( Figure 5), pentamerous, scape (I) short, reaching ca. apex of head, cylindrical, stout (about twice diameter of basipedicellite), remaining antennomeres slender, narrowly cylindrical, basipedicellite (IIa) longer than scape but about half the length of distipedicellite (IIb), basiflagellum (III) and distiflagellum (IV), all nearly same length (for exact lengths see Table 1). Joint between basipedicellite and distipedicellite inconspicuous, more or less fused . Bucculae (Figs 10-11) short, low, anteriorly rectangular without spine or produced into a short acutangulate spine (varies intraspecifically), posteriorly reaching about anterior margin of eye, evanescent ( Figure 11). Apex of rostral segment I slightly surpassing bucculae (Figs 10-11), apex of rostrum reaching anterior margin of metacoxae ( Figure 2); length ratio of rostral segments: II > I = III > IV, II about twice length of segment IV.
Abdomen with ventral surface regularly convex, without median keel or groove ( Figure 2). Abdominal segment III anteromedially with low, broadly rounded protuberance not reaching between metacoxae (Figure 2). Abdominal segments III-VII with anterior margins convex and posterior margins concave medially, more pronounced posteriad; segment VII anteriorly distinctly produced forwards, longer medially than preceding segments ( Figure 2). Spiracles concolorous with surrounding abdominal surface, each not surrounded by a callosity. Trichobothria 2 + 2 on each abdominal segment, arranged immediately behind stigma, one on each side.
Measurements. See Table 1. The five species-group taxa we recognize more or less overlap in all measurements that were taken. Differential diagnosis. Greve (2010) and Rider et al. (2018) characterized members of the tribe Chlorocorini as being medium to large in size, green (fading to yellow after death), and somewhat depressed. They also noted that the head is usually flat dorsally, subtriangular with the apices of the mandibular plates often acute or spinosely produced. The antennae are pentamerous. The anterolateral margins of the pronotum typically are each provided with a row of small to large denticles, and the humeral angles are often prominently spined. The metathoracic scent gland peritremes are usually spout-shaped, relatively short, and do not extend beyond the middle of the metapleuron; the associated evaporatoria typically are large and extensive. The mesosternum is provided with a medial longitudinal carina that does not project forward onto the prosternum. In most included genera, the apex of each femur is provided with a short, dorsal tooth; the tarsi are three-segmented. In all but one included genus, the base of the abdomen is unarmed; that is, lacks a forward-projecting spine or tubercle. Greve (2010) also noted that in most genera, the ventral rim of the pygophore is produced into a process, the so-called hypandrium.
The genus Rhyncholepta fits the above criteria except that the head, although relatively flat dorsally and subtriangular, does not have the apices of the mandibular plates acute or spinose, but are narrowly rounded ( Figure 9); they typically are reddish brown with pale yellowish green areas in life; the pale areas fade after death. Rider et al. (2018) included the following genera in Chlorocorini: Arvelius, Chlorocoris, Chloropepla, Eludocoris, Fecelia, Loxa, Mayrinia, and Rhyncholepta. Rhyncholepta can be separated from the above genera by the dorsal coloration (e.g., Figs 1,3,[5][6][7][8]. Coloration is consistent among species of Rhyncholepta: reddish brown, with a large, impunctate pale spot on each basal angle of the scutellum and another pale, impunctate area along each anterolateral margin of the pronotum. This color pattern is not seen in any other chlorocorine species. A few species in other genera may have small pale spots or areas but these are usually confined to the hemelytra. Rhyncholepta can be distinguished from Arvelius by the unarmed abdominal base (spined in Arvelius) and the less developed mesosternal carinae (much more elevated in Arvelius). The apices of the mandibular plates are acute to spinose (with lateral margins of the mandibular plates relatively straight) in Arvelius, Chlorocoris (except the subgenus Monochrocerus), Chloropepla, Fecelia [acute only in F. minor (Vollenhoven, 1868)], Loxa, and Mayrinia. The apices of mandibular plates are narrowly rounded only in Rhyncholepta and Chlorocoris subgenus Monochrocerus; they are broadly rounded in Eludocoris (the head is broad apically, not subtriangular). Both Chloropepla and Eludocoris have elongate, apically acuminate metathoracic scent gland peritremes that separate those genera from all other chlorocorine genera, including Rhyncholepta. Furthermore, Chlorocoris and some species of Chloropepla lack the apical tooth on each femur that is present in all other chlorocorine genera.
Etymology. The generic name is composed of the Ancient Greek words ρύγχος (rhýnchos, = snout, muzzle, beak) and λεπτός (leptós, = thin), referring to the slender rostrum of the species. The gender is feminine, as it is evident from its ending -a and original combination with the adjective grandicallosus (-a, -um) given by Bergroth (1911) in its feminine form grandicallosa.
Bionomics. Based on label data and Joe Eger's and Roland Lupoli's field experience, most of the specimens were collected by various types of light traps (UV, mercury vapor, metal halide, black, GemLight and Polyvie). GemLight and Polyvie traps are automatic light traps with visible light from LED, blue, pink, white or green; SEAG (= Société Entomologique Antilles-Guyane) is performing year-round surveys of insects in French Guiana using those traps (R Lupoli, pers. comm.). Almost all of the traps were exposed to fairly dense forest or adjacent to such a forest, except in Macouria, where one specimen was collected in the littoral secondary forest and one in the savanna. They have never been seen when collecting by hand catching, sweeping, or beating the vegetation during the day or night by JE Eger (pers. observ.) or R Lupoli (pers. comm.). One specimen was collected by flight intercept trap at Matiti, French Guiana, but there were no specimens of Rhyncholepta collected by glass interception traps operated by the SEAG during 3-4 years (R Lupoli, pers. comm.).
Collecting dates of the specimens examined indicate that species of Rhyncholepta are found year round, although distinct peaks might occur (Figs 94-98, especially in the case of Rh. grandicallosa grandicallosa).
Distribution . The genus currently includes four species, one of them subdivided into two subspecies, distributed in the Neotropical Region from southern Mexico (Chiapas) to Bolivia and northwestern Brazil (Amazonas, Rondônia).
Species composition and delimitation. Our examination of 1125 specimens revealed five more or less distinct morphotypes based almost exclusively on structure of the male genital capsule and especially the hypandrium (expanded portion of ventral rim). The five morphotypes may be grouped by morphological similarity as ((grandicallosa grandicallosa + grandicallosa centroamericana) (henryi (meinanderi + wheeleri))).
Rhyncholepta grandicallosa differs from all three species of the Rh. meinanderi species-group by the following main characters: i) Genital capsule in ventral view with ventral rim apically bilobed, with small, shallow, V-shaped notch medially, hypandrial projections not visible in this view . ii) Anterior hypandrial projections large, lobe-like, apically rounded (72)(73)(74). iii) Lateral hypandrial projections long, directed anteriad and golf-club shaped (Figs 54-59: lp). iv) Posterior hypandrial projections short, spinose, situated more laterally, directed ventrally (Figs 42-47: pp), not visible in ventral and dorsal views (54)(55)(56)(57)(58)(59). v) Phallus with aedeagus strongly S-shaped apically (Figure 82: ae). Within the morphotype of Rh. grandicallosa, the variability in shape of the anterior and lateral hypandrial projections enables two subtle, but stable, subtypes to be recognized. Differences between these subtypes are smaller than those between any two morphotypes/species of the Rh. meinanderi species-group, and both of the subtypes represent strictly allopatric populations. We, therefore, decided to classify them as subspecies: Rh. g. grandicallosa in South America and Rh. g. centroamericana subsp. n. in Central America.
These morphotypes represent three related species that form the Rh. meinanderi species-group defined by the characters mentioned above. Ryncholepta henryi sp. n. differs from Rh. meinanderi and Rh. wheeleri sp. n. by its different shape and position of the posterior hypandrial projection (narrowly rounded apically, directed laterally; Figs 37, 49, 61, 75: pp), and by the prominent posterolateral angles of the genital capsule (a character shared with Rh. grandicallosa). Rhyncholepta meinanderi and Rh. wheeleri sp. n. share the short spinous, ventrally directed posterior hypandrial projection (Figs 39,41,51,53,63,65,(76)(77) and obtusangulate angles of the genital capsule. Both species differ in the shape of the three hypandrial projections (see key below).

Rhyncholepta grandicallosa grandicallosa
Apex of scutellum with anteapical black V-shaped stripe usually reduced to small black spot at lateral margin at anterior end of apical V-shaped callosity (Figs 14-17). However, two examined males (♂ [ Figure 18      Female genitalia. Posterior edges of laterotergites VIII abruptly attenuated apically, as long as or slightly more prominent posteriad compared with laterotergites IX (Figure 90). Internal female genitalia described in detail by Becker and Grazia-Vieira (1971: figs 14, 16).
Differential diagnosis. See characters in the key above. Most specimens of this subspecies differ from Rh. henryi sp. n. by the incomplete black V-shaped band anteapically on scutellum; however, this character does not work for all specimens.
Records from Colombia, Guyana, and Suriname require confirmation based on males. The subspecific identity of Rh. grandicallosa population from Chocó, Colombia requires revision.
Comments. Bergroth (1911) described the species based on the female sex, but did not indicate the number of specimens (syntypes) examined, though the fact that a single measurement and not a range was given for the body length ('Long. ♀ (sine membr. [= without membrane]) 11 mm) suggests that he had only one specimen. Bergroth (1914: fig. 6) provided a color painting of an adult. Neither of the Bergroth's two papers mentioned the depository of the type(s). Pirán (1956: 29, 35: fig. 1) illustrated the male genitalia of a specimen from Bolivia and designated the specimen as the allotype. The designation of a male allotype by Pirán (1956) is an invalid action without nomenclatural consequence because his specimen was not a part of the original type series (see ICZN 1999: Article 72). Furthermore, his illustration more closely conforms to Rh. meinanderi as described by Becker and Grazia-Vieira (1971). Becker and Grazia-Vieira (1971: 396) referred to a female holotype from French Guiana, deposited in the collection of the MZHF. We consider the action of Becker and Grazia-Vieira (1971: 396) as a valid lectotype designation under Article 74.6 (ICZN 1999) because the term holotype was used explicitly for the only existing (syn) type specimen. Becker and Grazia-Vieira (1971) distinguished two species of the genus Rhyncholepta. They interpreted Rh. grandicallosa based on their examination of the lectotype and described its male and a new species, Rh. meinanderi, which differs from Rh. grandicallosa in structure of the male and female genitalia : figs 2, 3 versus 4, 5 and 12 versus 13).
Our revision of the genus Rhyncholepta, however, reveals five taxa that are indistinguishable based on coloration, structure of body and pregenital abdomen, vestiture, and morphometric characters (see Table 1). The most promising external character, the development of the black V-shaped anteapical band on the scutellum and its apical Vshaped callosity, might help in identifying specimens of Rh. grandicallosa grandicallosa versus Rh. henryi, but we found two males of Rh. g. grandicallosa from French Guiana with a complete V-shaped band on the scutellum, as in Rh. henryi. This character also varies widely in Rh. grandicallosa centroamericana. The painting by Bergroth (1914), depicting almost certainly the lectotype of Rh. grandicallosa, shows an apparent black V-shaped band anteapically on the scutellum. The black V-shaped band, however, is not well delimited in recent photographs of the lectotype (see Figure 5), which might be attributed to inaccuracy of the painting or fading of the specimen's coloration during a century of preservation.
The female external genitalia allow Rh. meinanderi to be distinguished from both subspecies of Rh. grandicallosa and Rh. henryi sp. n., but those taxa cannot be reliably separated based on this character (Figs 93 versus 90-92). Also, the internal female genitalia did not provide suitable identification characters. Moreover, the female of Rh. wheeleri sp. n., the taxon probably most closely related to Rh. meinanderi, remains unknown.
The structure of the male genital capsule and, to a lesser extent, of the phallus thus remain the only reliable characters for identifying species of Rhyncholepta. The presence of two sympatric taxa in French Guiana, the type locality of Rh. grandicallosa, required reconsideration of the identity of this taxon. Careful examination of the photographs of the lectotype provided by MZHF confirmed that, in the absence of a reliable character allowing identification of female Rh. grandicallosa and Rh. henryi, the lectotype is not sufficient to determine the specific identity of Rh. grandicallosa. We decided to follow Article 75.5 of ICZN (1999) by petitioning the International Commission on Zoological Nomenclature to suppress the existing non-informative lectotype and replace it with a male neotype. Herein we suggest a suitable male neotype, which is properly documented to fulfill all requirements of Article 75.3 of ICZN (1999) and conserves the identity of Rh. grandicallosa sensu Becker and  and all subsequent authors. The case is being submitted to the ICZN simultaneously with this paper (Kment et al., submitted).
Measurements. Bionomics. Most specimens were collected by various types of light traps (UV light, mercury vapor light, metal halide light, black light) in or adjacent to dense forests. According to JE Eger, it has never been collected by hand catching, sweeping, or beating vegetation during the day or night. In Panama, three specimens were collected by "beating of forest vegetation along strips for boat navigation signs" (J Sekerka, pers. comm.) and one in "lower montane forest, [by] individual collecting" (J Hájek, pers. comm.) but without detailed information. Collection dates indicate that Rh. g. centroamericana occurs year round, though most specimens were collected between May and October ( Figure 95) Grazia-Vieira 1971, Arismendi andThomas 2003;present paper).  , Froeschner 1999, Arismendi 2002, Cambra et al. 2018 Diagnosis. Coloration, structure of head, thorax and pregenital abdomen, and vestiture as in other species of the genus (see redescription of Rhyncholepta above) except for the following characters.
Apex of scutellum with anteapical black V-shaped stripe well developed ( Figure  23). Apical V-shaped callosity thin, narrowly delineating margins of scutellum apex, branches forming more than half of length, tip of scutellum lacking conspicuous triangular callosity (Figure 23). Female genitalia. Posterior edges of laterotergites VIII suddenly attenuated apically, posteriorly about as long as laterotergites IX (Figure 92), indistinguishable from Rh. grandicallosa.
Etymology. We are pleased to dedicate the new species to our colleague, Thomas J. Henry, an excellent specialist in Heteroptera and curator of the USNM, on the occasion of his 70 th birthday. We much appreciate his generosity in helping visitors with literature or specimens in the USNM, including hosting colleagues in his home when they visited the collection.
Bionomics. Most specimens were collected by various types of light traps (UV light, mercury vapor light, white and blue LED) in or adjacent to dense forests. This species has never been collected by hand catching, sweeping or beating vegetation during the day or night (JE Eger, pers. observ.). Rhyncholepta henryi was found from November to February and from April to June, with most specimens collected in April ( Figure 96).
Etymology. The species was dedicated to Dr. Martin Meinander, former curator of Hemiptera in the Finnish Museum of Natural History, Helsinki .
Bionomics. Specimens mainly were collected by various types of light traps (UV light, mercury vapor light, black light) in or adjacent to dense forests. This species has never been collected by hand catching, sweeping, or beating vegetation during the day or night (JE Eger, pers. observ.). Adults have been collected in February, April-June, and August-December, with most in September and October (Figure 97) present paper).
Diagnosis. Coloration, structure of head, thorax and pregenital abdomen, and vestiture as in other species of the genus (see redescription of Rhyncholepta above) except for the following characters.