Taxonomic review of the Dichotomius (Luederwaldtinia) agenor species group (Coleoptera: Scarabaeidae: Scarabaeinae)

1 Federal University of Mato Grosso, Institute of Biosciences, Programa de Pós Graduação em Ecología e Conservação da Biodiversidade, Av. Fernando Correa da Costa, 2367, Boa Esperança, Cuiabá, MT, Brazil. 1 Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Praha-Suchdol, 16500, Czech Republic. 2 Federal University of Mato Grosso, Institute of Biosciences, Department of Biology and Zoology, Av. Fernando Correa da Costa, 2367, Boa Esperança, Cuiabá, MT, Brazil.

Dry specimens were hydrated and cleaned by immersing in hot water in an ultrasonic cleaner. Male genitalia were extracted following the widely described method by Zunino (1983), Tarasov & Solodovnikov (2011), Medina et al. (2013) and Tarasov & Génier (2015). Using a stereo microscope, entomological forceps and pins, the aedeagus was removed via the pygidium. The internal sac of the aedeagus was extracted using the methodology described by Medina et al. (2013) by gently pulling it through the basal phallobase foramen. The inner sclerites of the internal sac were cleared in KOH, heated in small beakers, for study. The nomenclature of the sclerites of the internal sac also follows Medina et al. (2013).
Type specimen label information was cited verbatim between quotation marks. Labels of the type specimens are separated by a slash "/". Square brackets "[]" were used to describe characteristics of each type label (e.g., [red with black margins], abbreviations used in brief descriptions: [hw] for handwriting; [p] for printed and [phw] for partially handwritten. In the lists of additional or non type material, country names are written in capital letters, the names of the provinces or departments are in bold (e.g.,Valle del Cauca) followed by municipality, geographic coordinates (when available), other complementary information, data and collector.
When necessary, lectotypes were selected and designated from syntypes deposited in the abovementioned collections/museums, to stabilize the nomenclature of the group. Group names used here refer to the oldest available species name in each group Nunes & Vaz-de-Mello 2013) and do not constitute valid taxonomic entities according to the International Code of Zoological Nomenclature (ICZN 1999).

Illustrations
All dorsal and ventral photographs were taken using a Canon EOS-T3i camera equipped with a macro lens EF 100 mm 1:2.8 Macro USM medium telephoto 1.0 × magnifi cation. The camera was controlled by an 'Automated Macro-rail Ford Focus Stacking StackShot' (COGNISYS.INC), which consists of a rail system that electronically controls and coordinates the movement and camera shutter.
cephalic carina bi-or quadrituberculate ( Fig. 1E-F), except for D. fornicatus and D. rafanunezi sp. nov., in which is trituberculate. Female sixth abdominal sternite twice as wide in the middle as in males and not narrowed medially.

Distribution
The distribution of the Dichotomius (L.) agenor species group is broad, from the north Pacifi c coast of Mexico (Sonora desert) to the central region of South America (Argentina: Santiago del Estero, Brazil: Mato Grosso state). Altitudinal range is variable, from nearly 3000 metres in the Andes mountain range to sea-level at the Atlantic or Pacifi c coast.  (Luederwaldt, 1923). B. D. amplicollis (Harold, 1869). C. D. belus (Harold, 1880). D. D. validipilosus (Luederwaldt, 1931 (Harold, 1869). B. Truncate as in D. sagittarius (Harold, 1869) stat. rev. C. Bifurcate as in D. belus (Harold, 1880). D. Cylindrical as in D. henripittieri sp. nov. E-F. Hypomeral characters. E. Medial disc smooth, lateral margin with multiple rows of setae as in D. amplicollis (Harold, 1869). F. Medial disc punctate, lateral margin with single row of setae as in D. tristis (Luederwaldt, 1923). G-H. Metasternum characters. G. Setigerous punctures from the medial and lateral edges joining throughout the margin of the mesocaxa as in D. enioi sp. nov. H. Setigerous punctures from the medial and lateral edges not joining throughout the margin of the mesocaxa as in D. centralis (Harold, 1869). I-J. Elytra interstriae. I. Smooth as in D. amplicollis. J. Shagreened as in D. agenor.

Diagnosis
Dichotomius agenor is separated from the other species in the group by the following combination of characters: large male fronto-clypeal carina with lower part wider than high, with median tubercle bifurcate apically, concave between central and lateral tubercles. Pronotum with pronounced, truncate anterior declivity, when viewed laterally. External margin of hypomeron bearing multiple rows of disorganized long setae, all approximately the same length, that can be seen in dorsal view. Posterior edge of metacoxa bearing two rows of disorganized ocellate punctures, separated by half the diameter of a puncture.
PRONOTUM. Wider than long and wider than elytra. Pronotal disc shiny and smooth, lacking deep punctures, with at most fi ne punctures. Anterior declivity pronounced and truncate when viewed laterally (Fig. 3D). Ocellate punctures present along anterior and posterior margins, few scattered ocellate punctures in lateral margins (Fig. 3A). Hypomeron medial disc punctures separated by three times the width of a puncture. External margin bearing multiple rows of disorganized long setae (see Fig. 2E).
ABDOMEN. Mesosternum and metepisternum fully covered by ocellate setigerous punctures, pilosity dense, setae all of same length. Metasternum setigerous punctures restricted mainly to lateral and anterior areas. Anterior lobe pilosity never connecting with lateral pilosity through margin of mesocoxae (see Fig. 2H). Lateral surface with ocellate setigerous punctures separated by twice the width of a puncture, variation in puncture diameter almost imperceptible. Ocellate punctation along anterolateral margins of sternites. Pygidium surface covered by small, fi ne punctures. Basal margin bearing few ocellate punctures.
ELYTRA. Interstriae shagreened, with fi ne, randomly separated punctures with interior shagreened microsculpture. Striae hardly marked, with ocellate punctures separated by twice the diameter of a puncture on elytral disc (see Fig. 2J).
LEGS. Metacoxa posterior edge bearing two contiguous rows of organized ocellate punctures, separated by half the diameter of a puncture (Fig. 3E).
PRONOTUM. Weak medial knob, only detectable in lateral view. Hypomeron setae longer and denser than in males.  placed this species in the assifer section which included species from the assifer and agenor groups. Harold's type material was from Colombia, but the label does not specify the exact locality. This species is known to occur in Panama, Colombia and Venezuela from 100 to 1500 m a.s.l., in the Caribbean subregion as proposed by Morrone (2001). It is found in the Magdalena and Maracaibo Provinces, associated with dry and humid forests (Morrone 2001

Diagnosis
Dichotomius amplicollis is separated from other species of the group by the following combination of characters: median tubercle of the fronto-clypeal carina twice as high as the two lateral tubercles, thick, cylindrical and with pronounced apical median emargination. Posterior surface of cephalic carina rugose. Anterior edge of pronotum with strong, abrupt declivity, apex with weak anteromedian lobe bifurcation. Posterior edge of metacoxa bearing a single row of organized, shallow ocellate setigerous punctures which merge together.

Material examined
Lectotype ( HEAD. Anterior surface rugose, not extending posteriorly to base of cephalic carina. Cephalic carina wider than high, posterior surface covered with deep punctures. Median tubercle twice as high as lateral tubercles, thick, cylindrical in shape and with strong apical emargination. Lateral tubercles with acute apex (Fig. 4D). Ventral clypeal process truncate and distally expanded. PRONOTUM. Wider than long, wider than elytra. Pronotal disc shiny, with smooth fi ne punctures. Anterior edge with pronounced declivity well-impressed punctures covering surface. Longitudinal sulcus weakly impressed, producing weak anteromedian lobe subemargination (as in Harold 1869); anterolateral surface with dense-impressed punctures next to antero-lateral fossae. Posteromedial edge with few dense and weakly impressed punctures near medial sulcus. Scattered ocellate punctures along anterior and posterior margins, absent in lateral margins (Fig. 4A). Hypomeron medial disc smooth. External margin bearing multiple rows of disorganized long setae (see Fig. 2E).
ABDOMEN. Mesosternum and metepisternum covered by large ocellate setigerous punctures, setae short. Metasternum setigerous punctures restricted to anterior and lateral areas. Anterior lobe pilosity connecting with lateral through margin of mesocoxa (see Fig. 2G). Lateral surface of metasternum with ocellate setigerous punctures separated by diameter of a puncture, setae long. Longitudinal sulcus conspicuous. Ocellate punctures along anterior margin of each sternite, denser in lateral areas, medial portion smooth. Pygidium surface smooth. Basal margin bearing some ocellate punctures.

Morphological variation
Females ( Fig. 4B) As males except for the following characters: HEAD. Completely transversely rugose, denser on anterior apical third. Fronto-clypeal carina quadridentate and greatly elevated, median tubercles higher than lateral.
PRONOTUM. Weak medial knob, discernible in lateral view, punctures dense and deeply impressed on lateral areas and near posterior margin of medial sulcus.
HYPOMERON. Setae longer and denser than in males.
ELYTRA. Striae, thinner and with smaller, ocellate punctures separated by diameter of a puncture at elytral disc.

Remarks
Dichotomius amplicollis is associated with tropical dry forests and is distributed across the Mexican Pacifi c coast province (Morrone 2001) in the states of Oaxaca (type locality) and Jalisco from 500 to 1900 m a.s.l. It is highly probable that it is also found throughout the states of Sinaloa, Nayarit, Michoacan and Colima. Individuals of this species are commonly confused with D. sagittarius stat. rev., in which the middle tubercle is not apically emarginate and the punctures of the posterior edge of the metacoxa are not merged together. Other characters of the male genitalia also differ between these two species.

Diagnosis
Dichotomius belus is separated from other species in the group by the following combination of characters: setae on body surface sparse or absent. Clypeal teeth generally reduced in large males and in most cases completely absent in females. Male cephalic carina conical, antero-posteriorly fl attened and curved anteriorly, higher than wide. Ventral clypeal process greatly emarginate.

Material examined
Lectotype (  PRONOTUM. Gibbous, imperceptibly emarginate at antero-medial portion. Wider than long, as wide as elytra; pronotal disc shiny, with fi ne indistinct punctures. Medial sulcus weakly impressed. Ocellate punctures along posterior and anterior margins (Fig. 5A, D, G), absent in lateral margins. Hypomeron with broad ocellate setigerous punctures separated by less than half the width of a puncture. Medial disc smooth, without punctures. External margin bearing multiple rows of disorganized long setae when seen in dorsal view (see Fig. 2E).
ABDOMEN. Mesosternum covered by large ocellate setigerous punctures, setae as long as in mesosternum. Metepisternum smooth with some weakly marked punctures. Metasternum setigerous punctures restricted mainly to lateral areas. Antero-median portion with some feebly marked punctures next to apical margins of coxa. Lateral surface of metasternum with ocellate punctures separated by two or three times width of a puncture, some punctures with long setae. Metepisternum suture clearly visible. Ocellate punctures along anterior margin of each sternite, denser in lateral areas, without reaching the centre. Pygidium surface covered by fi ne punctures, basal margin with wide punctures that merge at the centre.

Remarks
Dichotomius belus is endemic to Colombia and is distributed throughout the dry zones of the Andes mountains and lowlands associated with the interior of the Tropical Dry Forests. Based on the original description, specimens used to describe the species were collected in Medellín, Ambalema and Ocaña.

Diagnosis
Dichotomius centralis is separated from the other species in the group by the following combination of characters: pronotum covered by dense subrugose punctures. Elytral striae strongly marked, wide and crenulate, easily observable by unaided eye, punctures undefi ned and crenulate, separated by the width of a puncture.

Material examined
Lectotype ( HEAD. Most of clypeal and genal surface rugose. Cephalic carina wider than high, anterior surface rugose. Median tubercle twice as high as lateral tubercles, conical in shape and not emarginated at apex; surface smooth, posterior portion rugose. Ventral clypeal process truncate and distally expanded (see Fig. 2B).
PRONOTUM. Twice as wide as long. Anterior portion displaying accentuated declivity, dense sub-rugose punctures reaching antero-lateral fossae, separated by the width of a puncture (Fig. 6D). Pronotal disc covered by simple punctures, each of these punctures with fi ne microsculpture. Longitudinal sulcus weakly impressed. Anterior and posterior margins bearing row of disorganized ocellate punctures. Hypomeron middle edge smooth, without punctures. External margin with single row of disorganized long setae, all approximately same length.
ABDOMEN. Mesosternum and metepisternum covered by large ocellate setigerous punctures. Metasternum setigerous punctures restricted mainly to lateral and anterior areas. Anterior lobe pilosity does not connect with lateral pilosity through margins of mesocoxa (see Fig. 2H). Lateral ocellate punctures separated by three times width of a puncture, setae long reaching metepisternal suture, suture visible. Longitudinal sulcus weakly marked. Ocellate punctures along anterior margin of each sternite, denser in lateral areas. Pygidium surface covered by simple punctures, basal margin bearing dense ocellate punctures.
LEGS. Metacoxa posterior edge bearing single row of organized ocellate setigerous punctures, separated by width of a puncture. PARAMERES AND LAMELLA COPULATRIX. As in Fig. 6C, E-F.

Morphological variation
Females ( Fig. 6B) As males except for the following characters: HEAD. Surface completely rugose. Fronto-clypeal carina quadridentate, median tubercles higher than lateral. PRONOTUM. Weak medial knob, inconspicuous, observable in lateral view. Anterior and lateral surface covered by subrugose punctures fading towards medial disc. Hypomeron setae longer and denser than in males.
ELYTRA. Striae wider. Striae punctation undefi ned, crenulate and separated by half, or less width of a puncture.

Remarks
This species occurs in Belize, Costa Rica and Guatemala. The original description specifi ed that the type series was collected in Granada, Nicaragua. Other published works report it for El Salvador (Kohlmann & Solís 1997;López-Guerrero 2005). López-Guerrero (2005) argues that it is marginally likely to fi nd this species in the south of Mexico, precisely in the state of Chiapas due to the proximity to Guatemala. (Harold, 1869)

Diagnosis
Dichotomius deyrollei is separated from the other species in the group by the following combination of characters: clypeus with central emargination displaying two rounded, dorsally angled clypeal teeth. Cephalic carina, higher than wide, antero-posteriorly fl attened. Median tubercle approximately twice as high as lateral tubercles and gently inclined anteriorly, apically expanded and emarginate. Anterior portion of pronotum displaying sharp declivity, antero-medial area deeper and convex than lateral and where the longer, median tubercle can fi t if head capsules is rotated dorsally.

Material examined
Lectotype ( HEAD. Surface of anterior third rugose not reaching base of cephalic carina. Clypeus central emargination separating two rounded and dorsally angled clypeal teeth (Fig. 7A, D). Cephalic carina higher than wide, antero-posteriorly fl attened; anterior surface with well-marked punctures. Median tubercle approximately twice as high as lateral and gently inclined anteriorly, expanded and emarginate apically. Lateral tubercles, in frontal view, with two acute apices (Fig. 7D). Ventral clypeal process truncate (see Fig. 2B).
PRONOTUM. Wider than long. Pronotal disc shiny and smooth, covered by fi ne punctures. Antero-medial edge with strong convex declivity, which in the centre could accommodate the large frontal carina (Fig. 7A). Row of interrupted ocellate punctures arranged along anterior and posterior margins, fewer and scattered on lateral margins. Hypomeron anterior edge, presenting rounded ocellate punctures with long setae, punctures separated by one time the width of a puncture. Hypomeron medial disc smooth (see Fig. 2E), without punctures. External margin bearing single row of organized long setae, all approximately of same length (see Fig. 2F).
ABDOMEN. Mesosternum and metepisternum fully covered by dense ocellate-setigerous punctures. Metasternum setigerous punctures restricted mainly to lateral and anterior areas (Fig. 7H). Pilosity of anterior lobe of metasternum connecting with lateral pilosity through margin of mesocoxa (Fig. 7H). Lateral surface of metasternum covered by ocellate setigerous punctures separated by twice width of a puncture, setae long and dense, covering lateral surface of metasternum and metepisternal suture. Ocellate setigerous punctures along antero-lateral margins, denser at lateral areas. Pygidium surface covered by fi ne punctures, basal margin with scattered ocellate punctures.
LEGS. Metacoxa posterior edge bearing single row of disorganized setigerous punctures, separated by half or less the diameter of a puncture. PARAMERES AND LAMELLA COPULATRIX. As Fig. 7C, E-F.

Morphological variation
Females (Fig. 7B) As males except for the following characters: HEAD. Surface transversely rugose, denser on anterior portion. Cephalic carina with pair of high medial tubercles.

Remarks
This species occurs in Colombia and Venezuela. The distribution of the species closely follows that of the Andes Mountains. The original description notes that the type specimens were from "Brésil", without any other specifi cation of the locality. However, as far as we know this Andean species does not occur in Brazil.  HEAD. Anterior surface rugose. Interocular surface microsculpture shagreened, with fl at, well-defi ned punctures. Clypeus with central emargination separating two short, rounded clypeal teeth. Cephalic carina wider than high. Median tubercle twice as high as lateral tubercles, conical in shape and with fi ne apical emargination, lateral tubercles apical acute. Ventral clypeal process truncate (see Fig. 2B).

Dichotomius
PRONOTUM. Wider than long. Pronotal median disc shiny covered with simple well-impressed punctures, scattered dense uninterrupted ocellate punctures along anterior and posterior margins, absent in lateral margins (Fig. 8A, C). Anterior disc pronounced declivity with impressed longitudinal sulcus producing weak anteromedian lobe subemargination. Hypomeral disc smooth, external margin bearing multiple rows of disorganized long setae, approximately same length, (see Fig. 2E).
ABDOMEN. Prosternum surface microsculpture shagreened. Mesosternum and metepisternum surface covered by large ocellate setigerous punctures. Metasternum setigerous punctures restricted to anterior and lateral edges of mestasternal lobe. Setigerous punctures connecting antero-median edge with lateral through margin of mesocoxa (see Fig. 2G); lateral edge of metasternum with ocellate setigerous punctures separated by diameter of a puncture, setae reaching metepisternum suture. Sternite with ocellate punctures along anterior margins of each sternite, denser in lateral areas. Pygidium microsculpture shagreened with scattered well-impressed simple punctures; basal margin bearing row of ocellate punctures.

Morphological variation
Females (Fig. 8B) As males except for the following characters: HEAD. Surface completely transversely rugose, denser on anterior portion. Cephalic carina quadridentate and greatly elevate, median tubercles higher than lateral.
PRONOTUM. Without medial declivity and sub-emargination, punctures dense and deeply impressed, separated between them by once the diameter of same.
ABDOMEN. Sternites lateral punctuation denser than in males. Pygidium surface punctation wider and denser than in males.

Remarks
It is possible that Kohlmann & Solis (1997) and López-Guerrero (2005) reported this species for Central America as Dichotomius agenor.
PRONOTUM. Wider than long. Antero-median declivity of pronotal disc with two underdeveloped lobes at sides when viewed laterally (Fig. 9A). Pronotal disc shiny with dense deep punctures, separated by diameter of a puncture; margins rugose, denser at antero-lateral edges. Hypomeron medial disc smooth and shiny, external margin with single row of organized and scattered setae of same length. ABDOMEN. Mesosternum covered by large ocellate punctures separated by diameter of a puncture. Metasternum antero-medial edge smooth and shiny. Ocellate punctures restricted mainly to lateral edges, punctures separated by width of a puncture. Small ocellate punctures surrounding margin of mesocoxa (Fig. 9D). Ocellate punctures along the anterior margin of sternites; sixth abdominal sternite lower or depressed than others. Pygidium medial disc fi nely punctate, delimited by margin that widens towards apical part; basal inner margin rugose.
LEGS. Metacoxa posterior edge bearing row of small impressions, not punctures, separated by twice diameter of the impression. Setigerous punctures next to trochanter insertion larger, twice the size of small ones. PARAMERES AND LAMELLA COPULATRIX. As in Fig. 9C, E-F.

Morphological variation
Females (Fig. 9B) are distinguished from the males as follows: HEAD. Surface completely rugose, denser towards anterior portion. Cephalic carina trituberculate, median tubercle higher than lateral tubercles, surface punctate. Lateral tubercles narrow.
PRONOTUM. Weak medial depression, surface punctures greatly impressed separated by length of diameter of a puncture. Medial sulcus conspicuous.

Remarks
This species was fi rst described by Luederwaldt (1931) based on a female as a variety of D. opacipennis, placing it in the inachus section as part of the lucasi group. The holotype locality was Santiago del Estero, Rio Salado, the same later used by Pereira (1941) to described D. bosqi. The description of the male of this species was by Pereira (1941). Based on the abovementioned taxonomic characters and the possibility of comparing specimens to the holotype, we suggest these species to be synonyms. Within the species group, D. fornicatus and D. rafanunezi sp. nov. are the only species where the cephalic carinae of females are trituberculate.  HEAD. Wider than long. Anterior edge surface weakly rugose, extending posteriorly not reaching base of cephalic carina. Clypeo-genal surface covered by ocellate punctures spaced by one time diameter of a puncture. Interocular surface with ocellate punctures next to eyes (Fig. 10A, C). Clypeus rounded, weak central emargination separating two rounded clypeal teeth. Ventral clypeal process longitudinally enlarged, cylindrical (see Fig. 2D). Cephalic carina as wide as high, posterior surface shagreened microsculpture with ocellate shallow punctation. Median tubercle three times as high as lateral tubercles and curved posteriorly, apex rounded never bifurcate. Lateral tubercles obtuse at apex, vertically fl attened (Fig. 10C).
PRONOTUM. Twice as wide as long, and as wide as elytra. Anterior medial disc with weak declivity, not truncate. Median disc shiny and smooth, lacking deep punctures and having at most fi ne punctures. Antero-lateral surface with dense well-impressed simple punctures, scattered ocellate punctures also visible. Row of ocellate punctures along margins, punctures denser at anterior and posterior margins edges. Hypomeron medial disc punctation separated by three times width of a puncture, never smooth or impunctate. External margin bearing single row of organized long setae (see Fig. 2F).
LEGS. Metacoxa posterior edge bearing single row of disorganized ocellate setigerous punctures, separated by twice diameter of a puncture. Profemora displaying aggregation of setigerous punctures on distal ¾. PARAMERES AND LAMELLA COPULATRIX. As in Fig. 10E-G.
PRONOTUM. Surface covered by fi ne punctures, denser on antero-lateral areas. Punctuation on margins ocellate and dense, discernible. Hypomeron setae longer and denser than in males.

Remarks
This species was collected in the Henri Pittier National Park located on the ridge of the Cordillera de la Costa of Venezuela. The vegetation of the area is characterized by extensive cloud forest. (Felsche, 1901) Fig. 11, Map 8

Diagnosis
Dichotomius inachoides is separated from other species in the group by the following combination of characters: cephalic carina, wider than high, conical in shape. Median tubercle apex acute, higher than lateral tubercles. Lateral tubercles quadrate. Clypeal margin with tooth or protuberance before clypeogenal junction. Pronotum wider than long, anterior edge of pronotal disc with strong declivity displaying three gibbosities. HEAD. Anterior third rugosity not extending base of the central cephalic carina. Clypeus not rounded, with strong central emargination separating two acute clypeal teeth angled upwards. Gena protruding clypeal margin. Tooth or protuberance toward clypeo-genal junction. Cephalic carina wider than high, conical in shape and distinctly apically acute. Median tubercle twice as high as lateral tubercles, apex obtuse. Lateral tubercles quadrate, not apically acute (Fig. 11A, C). Ventral clypeal process truncate and broadened apically (see Fig. 2B).

Holotype
PRONOTUM. Wider than long, approximately twice as wide as long and wider than elytra. Anterior edge of pronotal disc with strong declivity displaying three gibbosities (Fig. 11A). Pronotal medial disc shiny with fi ne punctures, anterolateral edges close to fossae with fi ne dense punctures. Hypomeron medial disc smooth and shiny, anterior edge with ocellate setigerous punctures aggregated on inner anterior portion next to procoxa; punctures separated by half width of a puncture. External margin bearing rows of disorganized setigerous punctures, setae all approximately of the same length.
ABDOMEN. Prosternum surface shagreened exhibiting longitudinal rugosity and fi ne setigerous punctures. Mesosternum surface heavily shagreened, with large ocellate setigerous punctures separated by twice the diameter of a puncture. Metepisternum surface shagreened and covered by ocellate-setigerous punctures separated by twice diameter of puncture. Metasternum anterior portion next to basal margin of mesosternum and margins of mesocoxa covered by shagreened microsculpture and dense long setae. Dense pilosity surrounding margins of mesocoxa joining medial edges of metasternum with lateral (Fig. 11D). Longitudinal sulcus distinctly sculpted, ending as shallow mid-fossa. Sternites wide, opaque, with shagreened microsculpture. Small sparse ocellate punctures restricted to anterolateral margins of each sternite, never on middle portions. Pygidium completely delimited by margin, apical part with inner median tooth; surface smooth, large punctures restricted to basal margin. Medial and apical surfaces fi nely punctate. Punctures simple and well-imprinted.
ELYTRA. Opaque and black, wider than long. Interstriae microsculpture shagreened. Fine shiny punctures arranged randomly and visible only on 7 th and 8 th interstriae when teneral, otherwise not visible. Striae thin, punctures as wide as line that connects punctures. Punctures separated by at least twice diameter of same on elytral disc (Fig. 11A).

Morphological variation
Females (Fig. 11B, E) As males except for the following characters: HEAD. Surface rugose, becoming less dense on interocular space. Cephalic carina quadrituberculate, median tubercles higher than lateral.
PRONOTUM. Not modifi ed, at most weak medial knob, visible laterally. Surface shagreened with fi rmly impressed punctures separated by diameter of a puncture, denser at anterolateral margins. Welldeveloped females exhibiting rugose surface next to antero-lateral fossae (Fig. 11E). Pygidium surface smooth, delimited by incomplete margin, faded apically.

Remarks
This seems to be an uncommon species as there are not many specimens in collections. The few found were unidentifi ed. It is distributed throughout the Andes, more precisely on the east slope of the Andes mountain range. The key by   Diagnosis Dichotomius rafanunezi sp. nov. is separated from other species in the group by the following combination of characters: dorsal and ventral surface shiny green to dark green. Anterior edge of pronotum displaying sharp declivity, antero-medial edge lacking well-developed lobes as D. fornicatus. Cephalic carina twice as wide as high, median and lateral tubercles narrow. Metasternum anterior edge surface rugose. D. rafanunezi sp. nov. also differs from D. fornicatus by shape of male genitalia (aedeagus and internal sac of aedeagus).

Etymology
Dichotomius rafanunezi sp. nov. is named after Rafael V. Nunez, a great scientist and friend who contributes to the study on Scarabaeinae and the genus Dichotomius. HEAD. Anterior surface rugose, extending posteriorly to middle third not reaching base of cephalic carina (Fig. 12A, C). Cephalic carina narrow, twice as wide as high and vertically broadened, anterior surface with small fi ne punctures. Median tubercle twice as high as lateral tubercles, conical in shape and slightly curved posteriorly; lateral tubercles obtuse apically. Ventral clypeal process obtuse.

Holotype
PRONOTUM. Wider than long. Pronotal disc shiny covered by dense deep punctures, separated by width of a puncture. Anteromedial edge with distinct declivity, antero-lateral margins rugose (Fig. 12A). Hypomeron medial disc smooth and shiny. Lateral edge margin bearing single row of setae, all approximately of same length.
ABDOMEN. Prosternum and mesosternum surface shagreened, bearing round ocellate punctures of same size as on hypomera, punctures separated by width of a puncture (Fig. 12D). Metasternum antero-median portion next to mesocoxa rugose (Fig. 12H), with ocellate punctures along lateral areas separated by diameter of a puncture. Small ocellate punctures surrounding margins of mesocoxa. Ocellate punctures along antero-lateral margins sternites, larger on lateral edges. Sixth abdominal sternite and apex of the pygidium lower or depressed than other sternites. Pygidium delimited by margin that widens towards apex, surface covered by well-impressed punctures and basal margin bearing few scattered punctures that merges together.
LEGS. Metacoxa posterior edge bearing row of disorganized small, ocellate glabrous punctures, separated by width of a puncture. Setigerous punctures next to insertion of trochanter large, approximately twice width of smaller punctures. PARAMERES AND LAMELLA COPULATRIX. As in Fig. 12E-G.

Morphological variation
Females (Fig. 12B) As males except for the following characters: HEAD. Surface completely rugose, denser at anterior portion. Cephalic carina trituberculate, median tubercle higher than lateral and medially emarginate. Lateral tubercles narrow. PRONOTUM. Weak medial depression on anterior edge, surface covered by well-impressed punctures, separated by width of a puncture. Median sulcus conspicuous.
Dichotomius sagittarius stat. rev. is separated from other species in the group by the following combination of characters: head cephalic carina median tubercle approximately twice as high as lateral ones, conical in shape, weakly curved posterially and never bifurcated at apex. Anterior disc of the pronotum displaying moderate declivity, not abrupt and truncated as in D. agenor and D. amplicollis. External margin of hypomeron bearing multiple rows of disorganized long setae. Metacoxa posterior edge with single row of ocellate punctures, punctation never merges. Elytral interstriae shagreened.

Material examined
Lectotype (  HEAD. Anterior surface rugose, not extending posteriorly to base of cephalic carina. Cephalic carina wider than high. Median tubercle twice as high as lateral tubercles. Median tubercle conical in shape, weakly curved, apically obtuse and never bifurcate (Fig. 13C). Inter-ocular space shiny, smooth and surrounded by small shallow punctures. Ventral clypeal process truncate and expanded distally (see Fig. 2B).
PRONOTUM. Wider than long and wider than elytra. Anterior disk with moderate declivity, anterolateral surface next to fossae with fi ne punctures. Row of interrupted ocellate punctures along Pronotal margins, denser on anterior and posterior margins (Fig. 13A). Pronotal medial disc shiny, covered by fi ne punctures. Hypomeron disc smooth, lacking punctures. External margin bearing multiple rows of disorganized long setae, all approximately of same length (see Fig. 2E).
ABDOMEN. Mesosternum and metepisternum covered by dense ocellate setigerous punctures. Metasternum setigerous punctures restricted mainly to lateral and anterior areas of mestasternal lobe. Pilosity of antero-median portion connecting with lateral through margin of mesocoxa (see Fig. 2G). Metasternum lateral surface, with ocellate setigerous punctures separated by three times width of a puncture. Ocellate punctures along anterior margins of each sternite, denser in lateral sides, medial portion smooth. Pygidium basal margin bearing some ocellate punctures.
LEGS. Metacoxa posterior edge bearing single row of organized setigerous punctures, separated between them by one time diameter of a puncture, punctures never merge together (Fig. 13D). PARAMERES AND LAMELLA COPULATRIX. As in Fig. 13E-G.

Morphological variation
Females ( Fig. 13B) As males except for the following characters: HEAD. Surface completely transversely rugose, denser on anterior portion. Cephalic carina quadridentate, feebly elevated.
PRONOTUM. Weak medial knob discernible on lateral view, punctures denser and deeply impressed laterally.
ELYTRA. Striae, thinner with small punctures separated by twice diameter of a puncture on elytral disc.

Remarks
Dichotomius sagittarius stat. rev. was synonymized with D. amplicollis by López-Guerrero (2005). A detailed examination of the lectotype led us to conclude that D. sagittarius stat. rev. should be revalidated, as there are clear differences between the types and recently collected specimens of both species. The distribution of this species follows areas of dry forests of the Gulf of Mexico and the Yucatán peninsula across the Mexican east coast (Morrone 2001). According to Morrone (2001), these two areas are ecologically similar and comparable with areas in the province of Chiapas and the east and south of the Sierra Madre, suggesting that it is highly probable that D. sagittarius stat. rev. will be found in those areas. Dichotomius (Luederwaldtinia) simplicicornis (Luederwaldt, 1935) Fig. 14, Map 12 Pinotus simplicicornis Luederwaldt, 1935: 340 (original description).

Diagnosis
Dichotomius simplicicornis is separated from other species in the group by the following combination of characters: cephalic carina median tubercle higher than lateral ones, apically rounded and emarginate. Lateral tubercles short with acute on apex. Ventral clypeal process conical apically acute. Pronotum medial edge of the anterior disc declivity deeper than lateral sides, resembling two underdeveloped lobes. Elytral striae well marked, punctuation same width of striae; interstriae smooth.

Material examined
Lectotype ( HEAD. Anterior third surface transversely rugose, extending posteriorly not reaching base of cephalic carina. Interocular space smooth, with scattered deep punctures (Fig. 14C-D). Clypeal margin with large medial emargination separating two rounded clypeal teeth feebly angled upwards. Cephalic carina, wider than high and conical in shape (Fig. 14D). Median tubercle three times as high as lateral tubercles, apically rounded and emarginate. Lateral tubercles short and acute on apex (Fig. 14C). Ventral clypeal process conical in shape and apically acute.
PRONOTUM. Twice as wide as it is long, wider than elytra. Pronotal disc shiny and with well-impressed simple punctures, larger punctures on anterolateral edges and near posterior basal central margin. Anterior disc with sharp declivity, medial portion deeper than lateral sides, resembling two underdeveloped lobes (Fig. 14A, D). Hypomeron medial disc smooth and shiny, external margin bearing rows of disorganized setigerous punctures, setae all approximately of same length (see Fig. 2E).
ABDOMEN. Prosternum surface shagreened, with scattered ocellate setigerous punctures. Mesosternum and metepisternum surface shagreened, with large ocellate setigerous punctures, separated by less than twice diameter of a puncture. Metasternum anterior surface and margins of mesocoxa microsculpture shagreened, covered by dense long setae that surrounds the margins of mesocoxa, joining the anteromedial with lateral portions of metasternum (see Fig. 2G). Longitudinal sulcus distinctly sculpted, ending as shallow mid-fossa. Sternites with ocellate punctures along anterior margins. Pygidium delimited by incomplete margin, faded apically, large punctures restricted to basal margin, medial and apical surfaces fi nely punctate. ELYTRA. Shiny, wider than long. Striae distinctly punctate separated by two times diameter of a puncture on elytral disc; punctures same width of striae. Interstriae smooth with conspicuous randomly arranged punctures.
LEGS. Metacoxa microsculpture shagreened, posterior edge covered by row of dense setigerous punctures separated by less than diameter of a puncture, setae dense. In ventral view, profemora surface with scattered well-imprinted punctation, setigerous punctation restricted to medial edge.

Morphological variation
Females (Fig. 14B) As males except for the following characters: HEAD. Surface completely rugose. Space between clypeal teeth less separated than in males. Genae border protruding clypeal margin. Fronto-clypeal carina bituberculate.
ELYTRA. Twice as long as pronotum with shagreened microsculpture.

Remarks
The holotype has the fi rst half of the body (head and pronotum) of a male and the second half (abdomen) of a female. As the ICZN states in Article 73.1.5 "If a subsequent author fi nds that a holotype which consists of a set of components (e.g. disarticulated body parts) is not derived from an individual animal, the extraneous components may, by appropriate citation, be excluded from the holotype (material may be excluded from a hapantotype if it is found to contain components representing more than one taxon"; therefore, we here designate the head and the pronotum as lectotype. Endemic species from Peru and individuals cited by Chamorro et al. (2018Chamorro et al. ( : 95, 2019 from Ecuador were the rare species Dichotomius foveicollis (Kirsch, 1871). (Castelnau, 1840) Fig. 15, Map 13 Copris subaenea Castelnau, 1840: 79 (original description).

Diagnosis
Dichotomius subaeneus is separated from other species in the group by the following combination of characters: copper colour. Sparse or absence of setae on body surface. Cephalic carina narrow, wider than high. Ventral clypeal process greatly emarginate. Pronotum not modifi ed. Elytra striae displaying strong, well-imprinted punctuation separated between them by one time diameter of a puncture on elytral disc. Protibia apical spine bifurcate.

Morphological variation
Females (Fig. 15B) As males except for the following characters: HEAD. Clypeus elongate. Anterior surface completely rugose, interocular surface with well-impressed fl at punctures separated by twice diameter of a puncture. Cephalic carina quadri-dentate, triangular in shape. Median tubercles located forward lateral tubercles.

Remarks
This species is easily distinguished by its copper colour and sparse pilosity. As with D. belus, the protibial calcar spine is bifurcate.  mentioned the similarity of these two species to D. cuprinus (Felsche, 1901) and transferred it from the inachus group to the carbonarius group. After a detailed inspection of the lectotype and other specimens, we suggest that this species belongs to the D. agenor species group based on the shape of the cephalic carina. (Luederwaldt, 1923) Fig HEAD. Anterior edge surface horizontally rugose, interocular space displaying fl at punctures, resembling rough; distinct ocellate punctuation near eyes. Clypeus with central deep emargination separating two acute clypeal teeth (Fig. 16B-C). Cephalic carina bituberculate, wider than high, tubercles obtuse apically (Fig. 16C). Ventral clypeal process truncate (see Fig. 2B).
ABDOMEN. Prosternum surface with fi ne microsculptured, glabrous. Mesosternum and metepisternum surface microsculpture shagreened with ocellate setigerous punctures. Metasternum setigerous punctures restricted mainly to anterior and lateral edges of mestasternal lobe, puncture diameter variable. Punctuation of antero-median edge connecting with lateral ones through margin of mesocoxa (see Fig. 2G). Lateral edges of metasternum with ocellate, setigerous punctures separated by width of a puncture, pilosity sparse, setae short, not reaching metepisternum suture. Longitudinal sulcus clearly visible. Ocellate punctures along anterior margins of sternites. Pygidium ocellate punctation on basal edge and through lateral margins.
LEGS. Metacoxa posterior edge bearing single row of organized ocellate punctures, separated by diameter of a puncture. Posterior margin of meta-trochanter with long setae.

Morphological variation
Males (Fig. 16A) are distinguished from females as follows: HEAD. Cephalic carina higher than wide, conical in shape. Median tubercle twice as high as lateral tubercles, rounded, weakly bifurcate apically and curved posteriorly. Apex of lateral tubercles acute. PRONOTUM. Surface covered by fi ne punctures, denser at antero-lateral areas; anterior disc with weak declivity. PARAMERES AND LAMELLA COPULATRIX. As in Fig. 16E-G.

Remarks
This is an endemic species from Trinidad. The redescription was based on the well-developed female of the MZSP and the underdeveloped female at the CEMT. The male redescription was based on the specimen in the MZSP wrongly determined by Pereira as "Pinotus belus" and an underdeveloped male from the CEMT. Male genitalia were extracted from the underdeveloped male at CEMT. Luederwaldt (1923) also mentioned a male specimen in the type series that could not be traced.  (Luederwaldt, 1923) Fig. 17, Map 10
PRONOTUM. Wider than long. Anterior disc of pronotum presenting truncate declivity (Fig. 17D). Row of organized ocellate punctures along anterior and posterior margins, few on lateral margins. Pronotal median disc with fi ne punctures. Hypomeral disc punctures separated by three times diameter of a puncture, never smooth or lacking punctation. External margin bearing single row of organized long setae, all approximately of same length (see Fig. 2F).
ELYTRA. Interstriae smooth with fi ne randomly distributed punctures. Striae strongly marked, with ocellate punctures separated by diameter of a puncture on elytral disc.
LEGS. Metacoxa posterior edge bearing row of organized ocellate punctures, separated by diameter of a puncture. PARAMERES AND LAMELLA COPULATRIX. As in Fig. 17F-H.

Morphological variation
Females (Fig. 17B) As males except for the following characters: HEAD. Completely transversely rugose, denser on anterior portion. Cephalic carina bituberculate. PRONOTUM. Surface covered by fi ne punctures, denser at antero-lateral edges, ocellate punctures of margins denser, distinct on lateral sides. Hypomeron setae longer and denser than in males.

Remarks
Dichotomius tristis has historically been misidentifi ed, as it is commonly confused with D. agenor. The holotype that Luederwaldt (1923) used to describe the species was from Venezuela, lacking information on the specifi c locality. This species is known to occur in Colombia, Venezuela and Brazil below 1000 metres a.s.l., in the zones of Orinocoan piedmont, dry savannas or as stated by Morrone (2001), the provinces of Los Llanos Venezolanos and Roraima.

Diagnosis
Dichotomius validipilosus is separated from the other species in the group by the following combination of characters: head surface subrugose. Clypeus not rounded, clypeal margin displaying projection protruding on anterior portion of clypeo-genal suture. Cephalic carina conical, median tubercle apically emarginate, lateral tubercles slightly developed. Pronotal anterior disc with declivity, median edge deeper than lateral sides resembling two underdeveloped lobes. Pronotal median disc punctation fi ne. Anterior and lateral edges of metasternum with long and abundant setae. Elytral interstriae microsculpture shagreened. Sixth abdominal sternite marginally lower or depressed than other sternites.
PRONOTUM. Twice as wide as long and as wide as elytra. Pronotal median disc shiny and with fi ne punctures, ocellate punctures near posterior basal central margin. Anterior disc with sharp declivity, medial edge deeper than lateral sides, resembling two underdeveloped lobes (Fig. 18A). Hypomeron external margin bearing rows of disorganized setigerous punctures, median disc smooth and shiny (see Fig. 2E).
ELYTRA. Wider than long. Interstriae microsculpture shagreened (see Fig. 2J) with fi ne shiny punctures arranged randomly. Striae with ocellate punctures separated by once diameter of a puncture on elytral disc.
LEGS. Metacoxa surface microsculpture shagreened, posterior margin covered by row of dense setigerous punctures close together; setae dense, half the length of setae of metasternum.

Morphological variation
Females ( Fig. 18B) As males except for the following characters: HEAD. Anterior surface rugose, less dense on interocular space. Cephalic carina quadrituberculate; two median tubercles higher than lateral ones.

Remarks
The distribution of D. validipilosus and D. deyrollei overlaps and, although males can easily be differentiated, the females are quite similar and can only be distinguished by the pronotal punctation, which is lacking in D. validipilosus, and the character of the sixth abdominal sternite, which is marginally lower in D. validipilosus.

Discussion
The Dichotomius agenor species group has the highest diversity of any group of Luederwaldtinia that has been revised to date (Maldaner et al. 2015;Nunes & Vaz-de-Mello 2013;Nunes et al. 2016;Valois et al. 2017). The diversity and distribution of the species of the group were poorly known, which is not surprising given the ambiguous species boundaries, incorrect identifi cations and inaccurate geographic records of the specimens examined. Is important to emphasize that this species group shows a high degree of intraspecifi c variation which makes it diffi cult to identify specimens to the species level, leading to incorrect synonyms and descriptions of new species.
It is noteworthy that the D. agenor species group shares important characters with other species groups within the subgenus Luederwaldtinia. For example, D. agenor, D. assifer and D. speciosus possess an apical tooth on the meso-and metatibiae as well as the same type of pilosity and punctation pattern on the abdominal sternites (Nunes & Vaz-de-Mello 2013;Nunes et al. 2016). However, morphological characters were found indicating closer relationships between the species contained in D. agenor species group: 1. shape of the cephalic carina, 2. pronotal shape and 3. morphology of the lamella copulatrix (e.g., imperceptible variation of the apical sclerites and slight variation in the shape of the lamella copulatrix within the internal sac of the aedeagus), highlighting some putative synapomorphies. The latter characters solidly delimit the Dichotomius agenor species group within the genus Dichotomius and, more importantly, within the subgenus Luederwaldtinia.