Notes about morphological features of the Western Hemisphere subtribe Ardistomina, and revision of genus Semiardistomis Kult (Coleoptera, Carabidae, Scaritinae, Clivinini)

Pavel Valdés

doi:10.3897/zookeys.210.3042

. 2012 Jul 24;(210):19–67. doi: 10.3897/zookeys.210.3042

Show available content in

Notes about morphological features of the Western Hemisphere subtribe Ardistomina, and revision of genus Semiardistomis Kult (Coleoptera, Carabidae, Scaritinae, Clivinini)

Pavel Valdés ¹

PMCID: PMC3406452 PMID: 22859895

Abstract Abstract

Comparisons of structural features (principally mouthparts, elytral-abdominal locking mechanism, and female genitalia) of the ardistomine genera (Aspidoglossa Putzeys, Ardistomis Putzeys, and Semiardistomis Kult) with those features of members of the subtribe Clivinina (Clivina Latreille, Oxydrepanus Putzeys, Schizogenius Putzeys,Ancus Putzeys, Nyctosyles Putzeys, and Obadius Burmeister) confirm the taxonomic validity of the subtribe Ardistomina. Based on morphological features, the ardistomine genera are postulated to be related as follows: [Aspidoglossa [Ardistomis + Semiardistomis]]. Knowledge of this subtribe is further extended by taxonomic treatment of the genus Semiardistomis Kult. Of the 30 valid names of Semiardistomis previously recognized, four were proposed as variety names, and are listed as junior synonyms: Ardistomis labialis picipes Bates, 1881, Ardistomis labialis nanus Bates, 1881, and Ardistomis labialis dilatatus Bates, 1881; and Ardistomis pallipes caerulea Putzeys, 1846. Eight names, treated as specific epithets, are junior synonyms, as follows: Ardistomis (Semiardistomis) balthasari Kult, 1950 = Semiardistomis glabratus (Putzeys, 1866); Ardistomis (Semiardistomis) emdeni Kult, 1950 = Semiardistomis deletus (Putzeys, 1846); Ardistomis aenea Putzeys, 1866, Ardistomis (Semiardistomis) brittoni Kult, 1950, and Ardistomis (Semiardistomis) marani Kult, 1950 = Semiardistomis flavipes (Dejean, 1831); Ardistomis tuspanensis Putzeys, 1846 = Semiardistomis labialis (Chaudoir, 1837); Ardistomis (Semiardistomis) vlastae Kult, 1950 = Semiardistomis subglabra (van Emden, 1949); and Ardistomis striga Putzeys, 1866 = Semiardistomis pallipes (Dejean, 1831). Two new species described are Semiardistomis exspectatus sp. n. (type locality PERU, Madre de Dios, Rio Manu, 11°56'47"S, 071°17'00"W), and Semiardistomis major sp. n. (type locality PERU, Loreto, Rio Samiria, 05°12'S, 75°20'W). The 20 species of Semiardistomis are arranged intwo species–groups here proposed: the puncticollis group, including 12 species; and labialis group, including eight species. The species recognized are keyed, described or redescribed, and notes are provided about their Geographical distribution, habitat and activity. Distribution maps show known geographical ranges, from which are inferred patterns of speciation from a center of radiation in northern South America of both lineages.

Keywords: Coleoptera, Carabidae, scaritids, new species

Resumen Abstract

La comparación de las características estructurales (principalmente partes bucales, mecanismo de cierre élitro- abdominal y genitalia femenina) de los géneros ardistominos (Aspidoglossa Putzeys, Ardistomis Putzeys, y Semiardistomis Kult) con sus similares de miembros de la subtribu Clivinina (Clivina Latreille, Oxydrepanus Putzeys, Schizogenius Putzeys, Ancus Putzeys, Nyctosyles Putzeys, y Obadius Burmeister) confirma la validez taxonómica de la subtribu Ardistomina. Basado en características morfológicas, se postula una relación entre los géneros ardistominos de forma: [Aspidoglossa [Ardistomis + Semiardistomis]]. El tratado taxonómico del género Semiardistomis Kult extiende el conocimiento de esta subtribu. De los 30 nombres válidos previamente reconocidos, cuatro estaban propuestos como variedades, y se tratan como sinónimos: Ardistomis labialis picipes Bates, 1881, Ardistomis labialis nanus Bates, 1881, y Ardistomis labialis dilatatus Bates, 1881; y Ardistomis pallipes caerulea Putzeys, 1846. Ocho nombres usados como epítetos específicos resultan los siguientes sinónimos: Ardistomis (Semiardistomis) balthasari Kult, 1950 = Semiardistomis glabratus (Putzeys, 1866); Ardistomis (Semiardistomis) emdeni Kult, 1950 = Semiardistomis deletus (Putzeys, 1846); Ardistomis aenea Putzeys, 1866, Ardistomis (Semiardistomis) brittoni Kult, 1950, y Ardistomis (Semiardistomis) marani Kult, 1950 = Semiardistomis flavipes (Dejean, 1831); Ardistomis tuspanensis Putzeys, 1846 = Semiardistomis labialis (Chaudoir, 1837); Ardistomis (Semiardistomis) vlastae Kult, 1950 = Semiardistomis subglabra (van Emden, 1949); y Ardistomis striga Putzeys, 1866 = Semiardistomis pallipes (Dejean, 1831). Las dos especies nuevas descritas son Semiardistomis exspectatus sp. n. (localidad tipo PERU, Madre de Dios, Rio Manu, 11°56'47"S, 071°17'00"W), y Semiardistomis major sp. n. (localidad tipo PERU, Loreto, Rio Samiria, 05°12'S, 75°20'W). Las 20 especies de Semiardistomis se distribuyen en dos grupos de especies aquí establecidos: el grupo puncticollis con 12 especies y el grupo labialis con 8. Las especies reconocidas son incluidas en una clave de identificación, se describen o redescriben, y se dan notas a cerca de su distribución, hábitat y actividad. Los mapas de distribución muestran los rangos geográficos conocidos, de los cuales se infieren patrones de especiación a partir de un centro de radiación en el Norte de Suramérica para ambos linajes.

N’ayant vu qu’un seul individu, j’ignore si ces différences sont constantes et si l’insecte ne constitue pas une variété de l’A. pallipes.

(Putzeys, 1846: 646)

Between these extremes, however, there is, either in the same or other localities, every grade of variation

(Bates, 1881: 35)

The species of this group are very difficult to determine without preparing a key; they form some slightly different subspecies in some localities.

(Kult, 1950: 317)

Introduction

Although the major part of this paper treats the species of Semiardistomis, a more general background is provided by a preliminary treatment of the subtribe Ardistomina and comparison with other taxa of the tribe Clivinini, principally the nominotypical subtribe Clivinina. Many scaritid genera were included in the Ardistomina, but Bousquet (2006) restricted the subtribe to the genera Ardistomis, Semiardistomis and Aspidoglossa Putzeys; additional evidence presented in this work supports recognition of the group.

The quotations above provide an idea of past taxonomic difficulties regarding members Semiardistomis. Interpretations made using non-diagnostic characters from short series of specimens have led to a taxonomic system, mostly useless, in order to identify and correlate beetles of this genus. The first arrangement of the group was made by Putzeys (1866) who recognized common characters to designate his “deuxieme groupe” of genus Ardistomis Putzeys. Despite that, he placed the North American species of Semiardistomis Kult in a separate group; this structure started recognition of the group as a different entity from its generic origin.

Kult (1950) corroborated Putzeys’ taxonomic structure, naming the “deuxieme groupe” as subgenus Semiardistomis, which was divided into 8 groups, and the “troisieme groupe” as subgenus Ardistomiellus. Kult’s structure was built using characters that proved to be superficial, so species with different origin were placed in the same group. This new scheme resulted also in inclusion of some species of the genus Ardistomis in Semiardistomis, a mistake followed by subsequent authors until Valdes (2009) made the necessary corrections.

Whitehead [in Reichardt (1977)] suggested treating Semiardistomis as a distinct genus, but no formal action was taken until Nichols (1988b) did so. The last published list of species names of Semiardistomis was compiled by Lorenz (2005).

Material and methods

Study is based on 1038 specimens examined, provided by, or checked in, the following collections (names of curators or owners at the time of the loan in parentheses).

MHNP

IRSNB

CMN

IES

MNHNCu

PVCCu

PBPC

BMNH

HECO

UASM

ADVA

CAS

FSCA

USNM

Dissections of adults were made using standard techniques. The genitalia were preserved in glycerin in a microvial, pinned beneath the specimen from which they were removed. Mouthparts were glued on small cards pinned beneath the specimens. Observations were made using a stereobinocular microscope and a compound microscope. All line drawings were made from digital microphotographs using Corel Draw 13X.

The following measurements were made using an ocular micrometer: head length (HL): linear distance from apical margin of clypeus to posterior margin of right eye; length of pronotum (PL): linear distance from anterior to posterior margin along the midline; pronotal width (PW): greatest linear transverse distance; elytral length (EL): linear distance from basal ridge to apex along the suture; elytral width (EW): greatest linear transverse distance across both elytra. The standardized body length (SBL) is the sum of the lengths of head, pronotum and elytra. Body ratios (PW/EW, PW/PL, PL/EL and EW/EL) are given for each species. Mandible proportion is interpreted from ratio of the length of the transverse line at outer molar point (width) and length of the perpendicular distance from that line to apical edge (length).

Most terms used for structural features are found in previous works on Carabidae: Allen and Ball (1980) for adult microsculpture; Acorn and Ball (1991) for adult mandibles; Liebherr and Will (1998) for female genitalia.

Taxonomy

Subtribe. Ardistomina

Diagnosis.

Within the Clivinini. the subtribe Ardistomina is characterized as follows: Elytron latero-distally (Fig. 22) with a plica (ep) and an adjacent abdominal (segment VII) pleural projection (app) that together form an elytral-abdominal locking mechanism; ovipositor (Figs 27–30) with an asetose quadranguloid laterotergite, and unsegmented gonocoxa bearing at apex few long setae.

Figures 22–24. — 22 Body extremity (lateral aspect) of *Semiardistomis labialis* (Chaudoir) **23–24** Protarsus (ventral aspect) of *Semiardistomis* 23 *Semiardistomis labialis* (Chaudoir) 24 *Semiardistomis glabratus* (Putzeys). Legend: **app** abdominal epipleural projectionof abdominal sternum VII ep elytral plica. Scale bar 1 mm.

Figures 27–30. — Female genitalia (ventral aspect). of *Ardistomina* 27 *Semiardistomis glabratus* (Putzeys) 28 Semiardistomis labialis (Chaudoir) 29 *Ardistomis fasciolatus* Putzeys 30 *Aspidoglossa mexicana* (Chaudoir). Legend: bc bursa copulatrix gc gonocoxa (gonocoxite 1 and 2, fused) lt laterotergite mt mediotergite sp spermatheca **spd** spermathecal duct **spg** spermathecal gland **spgd** spermathecal gland duct.Scale bar 0.1 mm.

Included genera.

This subtribe includes Aspidoglossa Putzeys, Semiardistomis Kult, and Ardistomis Putzeys.

Comparative morphology.

Mandibles, labium, and female genitalia (source of many diagnostic features within the tribe Clivinini) were compared within the ardistomines and between that subtribe and selected members of the nominotypic Clivinina. The latter taxon was represented by Western Hemisphere members of six exemplar genera: Clivina Latreille, Oxydrepanus Putzeys, Schizogenius Putzeys, Ancus Putzeys, Nyctosyles Putzeys, and Obadius Burmeister. Also, mandibles of Dyschiriodes Jeannel (subtribe Dyschiriina) were included.

Mandibles: Compared to those of Dyschiriina (Figs 12A–12D), the mandibles of the clivinines (Figs 9A–9D to 11A–11D) and ardistomines (Figs 6A–6D to 8A–8D) are relatively straight.

Figures 6–12. — Mandibles ofArdistomina, *Clivinina* and *Dyschiriina* with length/width ratios: A left, dorsal aspect B right, dorsal aspect C left, ventral aspect and D right, ventral aspect) 6 *Semiardistomis labialis* (Chaudoir) 7 *Ardistomis fasciolatus* Putzeys 8 *Aspidoglossa mexicana* (Chaudoir) 9 *Oxydrepanus rufus* (Putzeys) 10 *Clivina dentipes* Dejean 11 *Schizogenius arimao* Darlington 12 *Dyschiriodes larochellei* Bousquet. Legend: Occlusal teeth: m molar pm premolar rt retinacular tt terebral. Ventral surface: vg ventral groove mt microtrichia. Scale bar 0.1 mm.

For dentition, Dyschiriodes exhibits the least number of occlusal teeth. The clivinine genera Clivina (Figs 9A–9D)and Oxydrepanus (Figs 10A–10D), and the ardistomine genera Aspidoglossa (Figs 8A–8D) and Ardistomis (Figs 7A–7D)have a full complement of occlusal teeth, Semiardistomis (Figs 6A–6D) and Schizogenius (Figs 11A–11D) lack the premolar tooth.

In values for L/W (a measure of relative length), the mandibles of clivinines, dyschiriines, and the ardistomine Aspidoglossa are relatively short (L/W 1.44–1.68), whereas the mandibles of the ardistomine genera Semiardistomis (L/W 1.86) and Ardistomis (L/W 2.25) are relatively long, with a slender terebra.

Labium: In form, the mentum (m) is markedly to slightly transverse (L/W 0.43–0.56) among the clivinine genera (Figs 17A–21A); among the ardistomine genera (Figs 13A–16A) the mentum is slightly transverse to slightly elongate (L/W 0.57–0.95), a morphocline being Aspidoglossa—Semiardistomis—Ardistomis.

Figures 13–21. — Labium ofClivinini (ventral aspects): A mentum and palpi B ligula C mental carina, lateral aspect. **13–14** Genus *Semiardistomis*: 13 S. glabratus (Putzeys) 14 *Semiardistomis labialis* (Chaudoir) 15 Ardistomis fasciolatus Putzeys 16 *Aspidoglossa mexicana* (Chaudoir) 17 *Clivina dentipes* Dejean 18 *Oxydrepanus rufus* (Putzeys) 19 *Schizogenius arimao* Darlington 20 *Ancus excavaticeps* (Putzeys) 21 *Nyctosyles planicollis* (Reiche). Legend: as apical setae of glossal sclerite gs glossal sclerite **lp2** labial palpomere 2 **lp3** labial palpomere 3 ll lateral lobes mc median carina m mentum mt mental tooth **pas** preapical seta of glossal sclerite pg paraglossa. Scale bar 0.1 mm.

In the Ardistomina, the apex of the lateral lobes (ll) is extended distally beyond the apex of the mental tooth (mt). This feature is varied among the clivinines: lateral lobes not extended beyond the apex of the mental tooth (Clivina, Oxydrepanus, and Nyctosyles, Figs 17A, 18A, 21A), to slightly extended beyond that line (Schizogenius and Ancus, Figs 19A, 20A).

The paraglossae (pg) are elongate, extended distinctly beyond the apex of the glossal sclerite (gs) in most genera of Ardistomina and Clivinina. In the ardistomine Ardistomis (Fig. 15B) and clivinine Nyctosyles (Fig. 21B) the paraglossae are much shorter than the glossal sclerite.

The glossal sclerite (gs) varies appreciably in both subtribes, being very large and rotund in Semiardistomis (Figs 13B, 14B4), broad with a broad apex in Nyctosyles (Fig. 21), and narrower and shorter in the remaining ardistomines and clivinines.

The glossal sclerite in the genus Semiardistomis has an extra pair of preapical setae (Figs 13B, 14B, pas). All other ardistomine and clivinine genera have a single pair of glossal setae (as).

Labial palpomere 3 (lp3) is elongate and fusiform in the Ardistomina (Figs 13A–16A). This sclerite varies in the clivinines: fusiform in Clivina (Fig. 17A), and variously widened in the remaining clivinine exemplar genera (Figs 18A–21A).

Female genitalia: The ovipositor sclerites come in two types, either ardistomine (Figs 27–30) or clivinine (Figs 31A–36A). For clivinine genera Clivina, Nyctosyles and Obadius, the gonocoxa is segmented, each segment designated as a gonocoxite (gc1, gc2). Gonocoxite 2 is more or less falcate. In ardistomine females, in contrast, the gonocoxa (gc) is unsegmented, and slightly curved or essentially straight. The laterotergites (lt) of clivinines are more or less triangular, whereas those of ardistomines are rectanguloid. Further, the laterotergites and gonocoxites of clivinines are setose along their margins, but the apex of gonocoxite 2 is glabrous. In contrast, for ardistomines, the ovipositor sclerites are essentially glabrous, but the apex of the gonocoxa bears a few setae. An unsegmented gonocoxa with reduced number of setae is also seen in Dyschiriina (Fedorenko, 1996). Within the ardistomines, the gonocoxae of Aspidoglossa and Ardistomis are moderately broad (Figs 29, 30), but those of Semiardistomis (Figs 27, 28) are slender, virtually rod-like.

Figures 31–36. — Female genitalia (dorsal aspect) and gonocoxites /laterotergites (lateral aspect) of *Clivinina* 31 *Clivina dentipes* Dejean 32 *Oxydrepanus rufus* (Putzeys) 33 *Schizogenius arimao* Darlington 34 *Nyctosyles planicollis* (Reiche) 35 *Ancus excavaticeps* (Putzeys) 36 *Obadius insignis* Burmeister. Legend: See legend for **Figs** **27–30**, except gonocoxite 1 (**gc1**) and. gonocoxite 2 (**gc2**) Scale bar 0.1 mm.

Within the Clivinina, the reproductive tract (Figs 31A–36A) is strikingly varied, but the range of variation is about as extensive as, and similar to, that of the Ardistomina, and thus uninformative from a diagnostic perspective at subtribal level. Within each subtribe, the genera are clearly distinguishable from one another. Here, I treat only the ardistomine genera.

In Aspidoglossa females (Fig. 30), the spermathecal duct (spd) is narrow, elongate, with few loose coils proximally; the spermathecal gland (spgd) is relatively short. The female tract of Ardistomis (Fig. 29) is narrow, relatively short; the spermatheca (sp) is moderately long and markedly expanded distally. For Semiardistomis females (Figs 27, 28) the reproductive tracts of the two species-groups are sufficiently different from one another to require separate descriptions. They also differ markedly from the reproductive tracts of Aspidoglossa and Ardistomis. For details, see species-group treatments, below.

Habitat.

The members of the Ardistomina are hygrophilous or mesophilous, living in riparian situations, lowland swamp forests, or wet montane tropical forest.

Relationships.

As indicated above, of the three ardistomine genera, Aspidoglossa is most similar to members of subtribe Clivinina in mandibular and mental proportions and is more remote from Ardistomis and Semiardistomis in structure of the female reproductive tract than the latter two genera are from each other. In turn, Ardistomis and Semiardistomis share elongate mandibles and mentum. Based on these observations, I conclude that relationships of these three genera may be summarized using brackets as follows: [Aspidoglossa [Ardistomis + Semiardistomis]]

Geographical distribution.

This subtribe is a Western Hemisphere indigenous group. Its range extends in South America east of the Andes mountain range from central Argentina northward through Colombia, Middle America, and the West Indies to temperate North America, principally east of the Mississippi drainage basin.

Genus. Semiardistomis

Kult, 1950

http://species-id.net/wiki/Semiardistomis

Ardistomis (Semiardistomis) Kult, 1950: 301. Type species: Clivina labialis Chaudoir, 1837, designated by Kult (1950: 301).
Ardistomis (Ardistomiellus) Kult, 1950: 303. Type Species: Ardistomis viridis Say, 1823, designated by Kult (1950: 303). Synonymy established by Whitehead [in Reichardt] (1977: 392).
Semiardistomis Kult. Nichols (1988b: 98); Ball and Bousquet (2001: 45, 74); Bousquet (2006: 10); Valdés (2007: 24); Erwin (2011: 233).

Diagnostic combination.

Features of adults used in recognition of this genus include: antennomere 2 shorter than antennomere 3 (Fig. 1, a2, a3); glossal sclerite of ligula (Figs 13B, 14B) with a secondary pair of setae; mentum with median carina (Figs 13C, 14C) extended distal in form of an appendiform keel; protibia (Figs 23, 24) with basal half of ventral surface with a group of setae.

Figures 1–2. — *Semiardistomis labialis* (Chaudoir). 1 Dorsal aspect 2 Ventral aspect. Legend: **a1 a2 a3** antennomeres 1–3, respectively. Scale bar 1 mm.

Description.

Adult. Body shape, color and size (Figs 1, 2, 37–41, 44–52): Body pedunculate. Body size small, ranging from 4.0 to 7.5 mm. Body monochromous, dark with metallic greenish and/ or brassy luster, shiny in species without microsculpture; appendages reddish brown. One species, Semiardistomis laevistriatus (Fleutiaux & Sallé), is dark brown a color also found in monticolous brachypterous species of the genus Ardistomis.

Figures 37–38. — 37 *Semiardistomis cordicollis* (Putzeys) 38 *Semiardistomis exspectatus* sp. n. Dorsal aspect. Scale bar 1 mm.

Figures 39–40. — 39 *Semiardistomis darlingtoni* (Kult) (teneral) 40 *Semiardistomis subglabra* (van Emden). Dorsal aspect. Scale bar 1 mm.

Figures 45–46. — 45 *Semiardistomis jedlickai* (Kult) 46 *Semiardistomis maindroni* (Kult). Dorsal aspect. Scale bar 1 mm.

Figures 47–48. — 47 *Semiardistomis laevistriatus* (Fleutiaux & Salle) 48 *Semiardistomis puncticollis* (Dejean). Dorsal aspect. Scale bar 1 mm.

Figures 49–50 — **. 47** *Semiardistomis major* sp.n. 50 *Semiardistomis rugosus* (Putzeys). Dorsal aspect. Scale bar 1 mm.

Figures 51–52. — 51 *Semiardistomis cyaneolimbatus* (Chevrolat) 52 *Semiardistomis pallipes* (Dejean). Dorsal aspect. Scale bar 1 mm.

Microsculpture: Frontoclypeus mostly smooth; supraantennal lobes smooth; vertex with mesh pattern isodiametric; gena with mesh pattern isodiametric; gula with mesh pattern transverse. Mandibles smooth; submentum and mentum with mesh pattern isodiametric. Pronotal disc generally smooth or with mesh pattern isodiametric, microlines very shallow, marginally and smooth at the center; proepisternum smooth or with isodiametric mesh pattern, submarginal band of microsculpture absent; prosternum smooth or with mesh pattern transverse. Metasternum smooth or with mesh pattern transverse. Abdominal sterna smooth or with mesh pattern transverse. Elytra smooth or with isodiametric mesh pattern covering entirely or only part of the disc.

Chaetotaxy: Two pair of supraorbital setae (except for Semiardistomis puncticollis); pronotal disc with two pair of marginal setae (except for Semiardistomis puncticollis and Semiardistomis viridis); except for hirsute species, setae on elytral disc located in interval 3 and Semiardistomis darlingtoni (Kult) also in interval 5; abdominal sterna IV-VII with accessory setae.

Head capsule: Clypeus with anterior margin concave medially; lateral lobes distinct, projected at the same level or below anterior margin. Antennal lobes prominent, sometimes partially sulcate medially in basal half. Frontoclypeus smooth except in Semiardistomis rugosus (Putzeys). Frontal impressions deep and wide from base of antennal lobes to anterior margin of clypeus. Gena with sides subparallel. Eyes: Hemispherical, prominent. Antennae (Figs 1, 2): Filiform to submoniliform. Antennomere 1 (a1) with single preapical seta. Antennomere 2 (a2) with few setae, shorter than antennomere 3 (a3). Antennomeres 4–11 densely setose, setae short.

Mouthparts: Labrum (Figs 3, 4): anterior margin angulate, dentiform medially (dp); dorsal setae (ds) 7, as for most Clivinini; apical portion of epipharyngeal setae (es) serrulate anteriolaterally. Maxillae (Fig. 5) with lacinia (lac) apical tooth sharp and curved; galeomere 1 (g1) slender, a little longer than galeomere 2 (g2), the latter flat, broad and sinuate in outline; palpomere 2 (mp2) thick and triangular in outline; palpomere 3 (mp3) subequal in length to palpomere 4 (mp4); palpomere 4 apically acuminate. Stipes (st) with 4 setae, palpifer (pf) with one seta. (This structure shows little difference from other clivinines being most similar to that of Ardistomis. Mandibles (Figs 6A–6D): elongate, about 1.9 times longer than wide; ventral groove (vg) moderate in length, with short microtrichia (mt); left mandible with terebral ridge curved, the terebral tooth (tt) blunt and moderate in size, visible from ventral view, retinaculum (rt) broad, premolar tooth (pm) absent, the molar tooth (m) broad and rounded; right mandible with terebral ridge more or less straight, the terebral tooth small, not visible from ventral view, the retinaculum with acute anterior tooth, premolar tooth absent, and the molar tooth broad and rounded. Labium (Figs 13A–C, 14A–C) with mental–submental suture complete; submentum with paramedian projections distinct, two pair of setae; mentum (m) trapezoidal, about 1.5 times wider than long; two pair of setae; lateral lobes with anterior margins angulate; mental tooth (mt) with distal margin almost straight, about 1/3 length of lateral lobes (ll); median carina (mc)(13C, 14C) extended distad, or not, beyond anterior margin of lateral lobes; pit organs (po) distinct, opened through oval orifices in basal part of mentum or on mental–submental suture; palpomere 3 (lp3) subequal in length to palpomere 2, palpomere 2 (lp2) bisetose; ligula (Figs 13B, 14B) with glossal sclerite (gs) notably wide, its anterior margin with acuminate median projection and two long setae (as), two additional small setae (pas) located preapically; paraglossae (pg) divergent from glossal sclerite and covered with microtrichia dorsally, lobes thin and acuminate, extended distally beyond distal margin of glossal sclerite, apices serrulate.

Figures 3–5. — **3–4** Labrum (dorsal aspect) 3 *Semiardistomis glabratus* (Putzeys) 4 *Semiardistomis labialis* (Chaudoir) 5 RightMaxilla (dorsal aspect) of *Semiardistomis labialis* (Chaudoir). Legend : Labrum: ds dorsal seta es epipharyngeal seta lp labral dentiform projection. Maxilla: c cardo g1 galeomere 1 g2 galeomere 2 **lac** lacinia **mp2 mp3 mp4** maxillary palpomeres 2–4 respectively pf palpifer s stipes. Scale bar 0.1 mm.

Pronotum. Ovate or cordate, anterior transverse and median longitudinal impressions distinct, proepisternum visible from above, lateral border not extended to base in some specimens. Anterior transverse and median longitudinal impressions distinct. Proepipleura visible from above.

Elytra. Oval, convex; striae complete or obliterated to various degrees or absent (stria 1 always complete), punctate or not, punctures shallowly to deeply impressed. Preapical epipleural plica (Fig. 22, ep) displaced outward, interrupting outline of elytra.

Hind wings. Macropterous or brachypterous.

Underside (Fig. 2). Metasternum with a row of setiferous punctures along margin of coxal cavity, median contact with abdomen dividing metacoxae. Suture between abdominal sterna III and IV obliterated at middle. Pleurite VII with small projection(Fig. 22, app) fitting into elytral epipleural plica (ep,).

Legs. Slender, protibia (Figs 23, 24) with basal half of ventral surface with a group of setae, protarsomeres in males slightly dilated.

Male genitalia (Figs 25, 26). Phallus lightly sclerotized; basal bulb with basal orifice (bo) oval, wide; basal projection (bp) distinct, apical margin curved; basal apophysis (ba) moderate; median portion tubular; apical portion formed by two lamellae (rl and ll). Endophallus pubescent in apical portion; basal sclerite (bs) clearly developed. Parameres subequal in length, the right one wider, both with 4-5 apical setae.

Figures 25–26. — Male genitalia of genus *Semiardistomis*: A phallus and parameres in dorsal aspect B phallus and endophallus everted in lateral aspect 25 *Semiardistomis labialis* (Chaudoir) 26 *Semiardistomis glabratus* (Putzeys). Legend: ba basal apophysis bo basal opening bp basal projection bs basal sclerite ll left lobe rl right lobe. Scale bar 0.1 mm.

Female genitalia (Figs 27, 28). Ovipositor: gonocoxa (gc) unsegmented, very slender, with a pair of setae at apex, surface with micropores; laterotergites (lt) thinly sclerotized, flat and asetose, sclerotized border thin and folded in basal portion with a small anterior part; mediotergite (mt) wide, its width delimited by external borders of laterotergites. Reproductive tract: bursa copulatrix (bc) elongate; spermathecal duct (spd) =distance from apex of bursa copulatrix to insertion point of spermathecal gland duct (spgd) relatively short or long, spermathecal gland duct elongate; spermatheca (sp) various in thickness, length, and conformation; see description of this structure for each of the two species-groups.

Morphological notes.

Cuticular sculpture: The absence of a submarginal band of microsculpture on the proepisternum has been used to differentiate Semiardistomis from Ardistomis but the character state is not diagnostic since the band has been lost in at least two lineages of Ardistomis (Valdes, 2009).

The microsculpture on the elytral disc has a diagnostic value, the absence of microsculpture being the apotypic state.

Vestiture: Hirsuteness is a common phenomenon in this genus. In the two species groups, this apotypic character state appears, its origin independently developed. In the puncticollis group, three species have hirsute structures: Semiardistomis puncticollis from southern U.S.A. (supraorbital area of the head capsule, pronotal disc, elytral disc, profemur and abdominal sternum VII), Semiardistomis pilosellus (Kult) from southern South America (elytral disc and profemur) and Semiardistomis subglabra (van Emden) from South America (profemur). In the labialis group, two species have hirsute structures: Semiardistomis viridis from southern U.S.A. (pronotal disc and elytral disc) and Semiardistomis propinquus (Putzeys) from Mexico (elytral disc),

Elytra: In this genus, I regard the state of having the striae complete and impunctate as plesiotypic, being present in both species groups.

Hind wings: Macropterous except Semiardistomis laevistriatus brachypterous. Nichols (1988a) also reported that Semiardistomis puncticollis is brachypterous.

Legs: Protarsomeres in males so slightly dilated that this feature is useless for sex recognition.

Male genitalia: Phallic structure enhances definition of the two species groups of Semiardistomis. See details, provided in the species-group diagnoses. The differences in the phallic structures are too small to separate the species within each group, a situation also known in other clivinine genera, such as Schizogenius Putzeys (see Whitehead 1972).

Larvae.

The first instar of Semiardistomis was described by Bousquet (2006). It was compared with Ardistomis larva by Valdes (2007) who pointed out two notable synapotypic features: absence of the coronal suture and a segmented maxillary palpomere 4.

Classification.

Based primarily on male and female genitalic features, the species of Semiardistomis are arranged in two species-groups designated as the puncticollis and labialis group, respectively.

Criteria for species definition.

Of the 20 known species of Semiardistomis only those occurring in U.S.A. (Semiardistomis viridis (Say) and Semiardistomis puncticollis (Dejean)) are represented by large series of specimens in collections (Nichols 1988a; Bousquet 2006). The species inhabiting Central and South America and the West Indies are represented in collections by few specimens which give only an incomplete picture of the ranges of the species.

Members of this genus are difficult to identify in part because of a shortage of useful external features, and in part because the male and female genitalia, so useful in distinguishing between species groups, are not useful within each group. Moreover, some of the characters traditionally used to separate the species have been found in large samples to vary extensively. Some samples are a mixture of combinations from extreme patterns considered as different species; being impossible to demonstrate if those populations are hybrids or simply polymorphs, while in other putative species, allopatric populations exhibit no evident differences. In the labialis group in southern South America, the species limits are especially difficult to assess probably because the group is young and composed of species with a great power of dispersal. Without direct evidence of the state of gene flow between known populations, it is almost impossible to testify in favor of the reproductive isolation of each species described or in other cases to designate subspecies. I will follow a criterion with a practical value, so maybe for some species, taxonomic determination will denote unintentionally a combination of extreme characters shared by more than one biological species.

Geographical distribution.

(Figs 57–59)The range of this genus is co-extensive with the range of the Ardistomina.

Figure 57. — Distribution map of members of the *puncticollis* species–group.

Figure 58. — Distribution map, illustrations of exemplar left elytra, and variability of members of the *labialis* species–group in South America. Value inside symbol indicates portion of basal elytra in which striae are impressed, (C, complete impressed). Scale bar 1 mm.

Figure 59. — Distribution map of members of the *labialis* species–group in Central America.

Key to described species of Semiardistomis, based on adult characters

1	Elytral disc plurisetose	2
1’	Elytral disc with setiferous punctures in interval 3, or sometimes also in interval 5	5
2(1)	Profemur plurisetose	3
2’	Profemur with the usual setae	4
3(2)	Pronotal disc plurisetose (along margin and on disc). Habitus as in Fig. 48. USA	Semiardistomis puncticollis(Dejean)
3’	Pronotal disc with the usual 2 pairs of marginal setae. Habitus as in Fig. 44. South America	Semiardistomis pilosellus (Kult)
4(2’)	Pronotal disc plurisetose along margin. Habitus as in Fig. 55. USA	Semiardistomis viridis (Say)
4’	Pronotal disc with the usual 2 pairs of marginal setae. Habitus as in Fig. 54. Mexico	Semiardistomis propinquus (Putzeys)
5(1’)	Elytron with two setiferous punctures on interval 3; humerus rounded; brachypterous. Habitus as in Fig. 47 Guadeloupe	Semiardistomis laevistriatus (Fleutiaux & Sallé)
5’	Elytron with three or more setiferous punctures on interval 3; macropterous	6
6(5’)	Elytron with three setiferous punctures on interval 3	7
6’	Elytron with more than three setiferous punctures on interval 3	12
7(6)	Elytral striae impunctate. Habitus as in Fig. 52. South America	Semiardistomis pallipes (Dejean)
7’	Elytral striae punctate	8
8(7’)	Elytral disc with isodiametric mesh pattern	9
8’	Elytral disc smooth	10
9(8)	Elytral striae impressed only in basal fifth, punctures deep along three-quarters of elytra, surface completely covered with isodiametric mesh pattern. South America	Semiardistomis deletus (Putzeys)
9’	Elytral striae obliterated in apical third, punctures moderately deep, surface with isodiametric mesh pattern, evanescent in central area of elytral disc in some specimens. South America	Semiardistomis flavipes (Dejean)
10(8’)	Elytral striae obliterated in apical fifth, punctures moderately deep. Habitus as in Fig. 51. West Indies	Semiardistomis cyaneolimbatus (Chevrolat)
10’	Elytral striae impressed only in basal fifth	11
11(10’)	Elytral punctures deeply impressed in basal two-thirds of elytra. Habitus as in Figs 1, 2. Central America	Semiardistomis labialis (Chaudoir)
11’	Elytral punctures moderately impressed in basal third of elytra. Southern South America	Semiardistomis semipunctatus (Dejean)
12(6’)	Elytral disc surface completely covered with isodiametric mesh pattern. Habitus as in Fig. 46. South America	Semiardistomis maindroni (Kult)
12’	Elytral disc surface smooth	13
13(12’)	Elytral striae complete; impunctate	14
13’	Elytral striae incomplete	17
14(13)	Front between antennal lobes with transverse rugae. Habitus as in Fig. 50. Southern Brazil	Semiardistomis rugosus
14’	Front between antennal lobes smooth	15
15(14’)	Elytron with five setiferous punctures on interval 3; body size more than 7 mm. Habitus as in Fig. 49. Peru	Semiardistomis major n. sp.
15’	Elytron with four setiferous punctures on interval 3; body size less than 6 mm	16
16(15’)	Pronotum markedly cordate, 1.25 times wider than long; humeri square, sides subparallel. Habitus as in Fig. 37. Colombia	Semiardistomis cordicollis (Putzeys)
16’	Pronotum subcordate, 1.14 times wider than long; shoulders rounded. Habitus as in Fig. 38. South America.	Semiardistomis exspectatus n. sp.
17(13’)	Elytron with eight setiferous punctures in interval 3	18
17’	Elytron with four setiferous punctures in interval 3	19
18(17)	Elytron with three setiferous punctures in interval 5. Habitus as in Fig. 39. Brazil	Semiardistomis darlingtoni (Kult)
18’	Elytron with interval 5 asetose. Habitus as in Fig. 40. South America	Semiardistomis subglabra (van Emden)
19(17’)	Elytral striae 3,4,5 and 6 impressed in basal half of disc, stria 2 present. Body length around 4 mm. Habitus as in Fig. 45. South America	Semiardistomis jedlickai (Kult)
19’	Elytral striae 3, 4, 5 and 6 impressed in basal third of disc, stria 2 absent. Body length around 6 mm. Habitus as in Fig. 41. South America	Semiardistomis glabratus (Putzeys)

Open in a new tab

Figures 41–44. — **41–43** *Semiardistomis glabratus* (Putzeys) 41exemplar from Peru, Loreto 42 exemplar from Argentina, Misiones 43 exemplar from Uruguay, Montevideo 44 *Semiardistomis pilosellus* (Kult). Dorsal aspect. Scale bar 1 mm.

Figures 54–55. — 54 *Semiardistomis propinquus* (Putzeys) 55 *Semiardistomis viridis* (Say). Dorsal aspect. Scale bar 1 mm.

The puncticollis species–group

This group is defined by the following: mentum with median carina (Fig. 13C) extended slightly distad anterior margin of lateral lobes (except Semiardistomis puncticollis with this structure (putatively) reduced); mental pit organs opened through oval orifices on the mental–submental suture. Males with wide phallus, undefined basal bulb (Fig. 26B) and a prominent, thickly sclerotized endophallic basal sclerite (Fig. 26A).

Female reproductive tract (Fig. 27; cf. Fig. 28) with spermatheca duct (spd) relatively short; spermatheca (sp) bent in its middle portion, wider from this point and with acute apex.

Included species

Semiardistomis cordicollis (Putzeys, 1846)

Semiardistomis darlingtoni (Kult, 1950)

Semiardistomis exspectatus sp. n.

Semiardistomis glabratus (Putzeys, 1866)

Semiardistomis jedlickai (Kult, 1950)

Semiardistomis laevistriatus (Fleutiaux & Sallé, 1889)

Semiardistomis maindroni (Kult, 1950)

Semiardistomis major sp. n.

Semiardistomis pilosellus (Kult, 1950)

Semiardistomis puncticollis (Dejean, 1831)

Semiardistomis rugosus (Putzeys, 1866)

Semiardistomis subglabra (van Emden, 1949)

Semiardistomis cordicollis

(Putzeys, 1846)

http://species-id.net/wiki/Semiardistomis_cordicollis

Figs 37 57

Ardistomis cordicollis Putzeys, 1846: 646; Lorenz 2005: 146.
Ardistomus cordicollis Putzeys: Csiki 1927: 547; Blackwelder 1944: 27.
Semiardistomis cordicollis (Putzeys); Erwin 2011: 233.

Type material.

Holotype at MHNP, pinned, labeled: handwritten “Lectotype Ardistomis cordicollis Putz. By Erwin 1976”/ “Lectotype Clivina labialis Chd. Des. S.W. Nichols 1984”/ printed in red paper “lectotype”/ handwritten in box “cordicollis Putzeys. Nlle Grenade C. Reiche”.

Type area.

Given by Putzeys (1866: 646) as “Nouvelle Grenade” = Colombia.