Dichotomius (Cephagonus) Luederwaldt, 1929

Nunes, Rafael V. & Vaz-de-Mello, Fernando Z., 2019, Taxonomic revision of Dichotomius (Cephagonus) Luederwaldt 1929 and the taxonomic status of remaining Dichotomius Hope 1838 subgenera (Coleoptera: Scarabaeidae: Scarabaeinae: Dichotomiini), Journal of Natural History 53 (37), pp. 2231-2351 : 2337-2344

publication ID

https://doi.org/ 10.1080/00222933.2019.1692088

persistent identifier

https://treatment.plazi.org/id/C740D609-2A09-BB37-FF02-E18AE0EF293D

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Valdenar

scientific name

Dichotomius (Cephagonus) Luederwaldt
status

 

Key for Dichotomius (Cephagonus) Luederwaldt View in CoL species

In this sectionı we provide a key for Cephagonus species revised in this work. Many Cephagonus as well as Dichotomius species have three distinguishable phenotypes: larger malesı usually with developed and conspicuous cephalic horns/carinası pronotal lobes and excavations (e.g.: Figure 40 View Figure 40 ). Medium to small-sized males do not have such structures as developed as it is on larger males; howeverı their puncture and hair distribution patterns and aedeagus are identical to larger males. Females differ from both males phenotypes by always having the sixth abdominal ventrite not shortened mediallyı usually three times wider than the fifth ventrite or/and having modifications on the median portion of it ( Figures 8 – 10 View Figure 8 View Figure 9 View Figure 10 ). Females clypeo-genal junction is usually more obtuse than on males and usuallyı they do not have develop cephalic horns and pronotal lobes. Besidesı head dorsal surface is transversely striated/wrinkled ( Figure 14 View Figure 14 (f)). We recommend associating similar males and females from the same locality and collecting event before proceeding to the identification. If you have a single female on handı it will only be possible to identify up to species level with locality informationı especially for those of quadraticeps and spadiceus groups. When not specifiedı characters fit for both small or large males and females.

1. Male sixth abdominal ventrite strongly grooved all along with its extension ( Figure 8 View Figure 8 (c)ı 10(a)) Females sixth abdominal ventrite having a ‘ u ’ shape emargination or a rounded lobe advancing beneath pygidium apex ( Figures 8 View Figure 8 (d-f)ı 10(b-c)) ........... 2

1 ʹ. Male sixth abdominal ventrite lacking strong groove all over its extension ( Figure 9 View Figure 9 (a)) Females sixth abdominal ventrite having three times the width of fifth and may have a pair of tuberclesı and/or triangular projections at mid-portion ( Figure 9 View Figure 9 (b-g)) ....................................................................................................................................................... 3

2. Larger males having four lobes at anterior portion of pronotal disc. Elytral striae with distinct punctures. Female sixth abdominal ventrite with a ‘ U ’ shape emargination at medial portion ( Figures 8 View Figure 8 (d)ı 15). Atlantic forest in Brazil (BAı ESı MGı PRı RJı SCı SP) ....................................................... D. (C.) ascanius (Harold) species-group (continues on 6)

2 ʹ. Larger males having simply convex pronotum. Elytral striae lacking distinct punctures near the basis. Female sixth abdominal ventrite with a bifurcated lobe advancing beneath pygidium apex ( Figure 10 View Figure 10 (b-c)). State of Espírito Santoı Brazil........................... ....... Dichotomius (Cephagonus) vargasae View in CoL n. sp. ( Figure 47 View Figure 47 (e-h)) (isolated species)

3. Male clypeo-genal junction obtuseı straightı sub-straight or having acute angleı in some cases expanded and strongly curved upward ( Figures 30 View Figure 30 (c)ı 31(b)ı 37(e)). Genal border straight or slightly curved inward and clypeal teeth always distinctly curved upward ( Figure 30 View Figure 30 (c)). Elytral striae and its punctures distinctly impressed; elytral interstriae convex (at least the first one in D. quadraticeps and D. semicircularis View in CoL ). Medial portion of female sixth abdominal ventrite or three times larger than fifth or/ and having a central pair of tubercles or protuberances ( Figure 9 View Figure 9 (e-f)) .................... 4

3 ʹ. Male clypeo-genal junction border is always obtuse and expanded ( Figure 43 View Figure 43 (f)). Genal border straight and clypeal teeth distinctly curved upward or not. Elytral striae and its punctures distinctly or weakly impressed; elytral interstriae flat. Medial portion of female sixth abdominal ventrite with a pair of triangular projections advancing beneath pygidium apex ( Figure 9 View Figure 9 (b)) ................................................................. 5

4. Flightless species – hindwing having half of elytra lengthı with atrophied cubital and anal venation ( Figure 7 View Figure 7 (h)); pronotum wider than elytra in dorsal view; elytra lacking humeral callus and strongly convex in lateral view. Open habitats in Central Brazil... ............................................ D. (C.) ingens (Luederwaldt) species group (continues on 15).

4. ’ Species capable of flight – hindwing having more than 1.5 the elytra lengthı all venation present ( Figure 7 View Figure 7 (g)); pronotum as wide as elytra in dorsal view; elytra having humeral callus and more convex only in the posterior portion. Forest habitats in South Americaı including Central Brazil... Dichotomius (Cephagonus) quadraticeps (Felsche) View in CoL species group (continues on 19).

5. BL beyond 20 mm (few smaller specimens with 15 – 20 mm). Anterior portion of the pronotum having fineı coarseı ocellate or elliptical punctures or striations (viewed under 20x magnification). Male cephalic horn usually produced in transversal cephalic carinaı with conicalı rounded or bifurcated apex; female cephalic carina straight or producing very weak tubercles. All elytra interstriae flat. Female sixth ventrite disc-lacking fine punctures in the mid-portion (viewed under 20x magnification) ................................................. ................... Dichotomius (Cephagonus) fissus (Harold) View in CoL species-group (continues on 9)

5 ʹ. BL usually under 20 mm (few larger males reaching 20 mm). Male anterior pronotal emargination lacking coarseı ocellate and deeply impressed puncturesı at most very fine ones (viewed under 30x magnification). Male cephalic horn produced in a single conical horn; female cephalic carina-producing pair of acute tubercles or produced in a single tubercle. At least 1st and 2nd elytral interstriae convex. Female sixth ventrite disc having fine punctures in the mid-portion (15 x) (as in Figure 8 View Figure 8 (f)) ..................................................................................................................... Dichotomius (Cephagonus) spadiceus (Luederwaldt) View in CoL species-group (continues on 13)

6. Elytra interstriae disc-bearing distinct microsculpture (chagrinated) (viewed under 20x magnification) ( Figure 13 View Figure 13 (f-g)). Atlantic forest above 1000 m in the states of Rio de Janeiro and São Paulo .......... Dichotomius (Cephagonus) mundus (Harold) View in CoL ( Figure 17 View Figure 17 )

6 ʹ. Elytra interstriae disc bearing distinct microsculpture (viewed under 20x magnification) ( Figure 13 View Figure 13 (a)). Atlantic forestı from sea level to 1500 .............................................. 7

7. Males with cephalic horn rounded at apex. Males elytra striae deeply impressed. Larger males having four anterior lobes on pronotal disc anterior portionı coarse and ocellate punctures restricted to the pronotal margins. Males pronotal disc smooth (fine punctures visible only with 50 x magnification). Metasternum almost glabrousı with few scattered hair ( Figure 8 View Figure 8 (a)). Paramera basal excavation reaching sides on dorsal view ( Figure 15 View Figure 15 (d)). Females sixth ventrite ‘ u ’ shape emargination having 1/7 of ventrite length ( Figure 8 View Figure 8 (d)). ......................................................................................................... ................................................ Dichotomius (Cephagonus) ascanius (Harold) View in CoL ( Figure 15 View Figure 15 )

7 ʹ. Larger males cephalic horn rounded at apex but produced in a cephalic carina; medium-to- smaller males with low cephalic carina with a pair of tubercles at apex. Males elytral striae shallowı weakly impressed. Larger male pronotum anterior portion widely excavatedı having a central emargination with two central lobes at the anterior portion of the disc. Anterior excavation with coarse punctures ( Figure 14 View Figure 14 (b)). Males pronotal disc with very fine puncture (150)ı equally spaced by twice their diameter. Metasternum bearing long hair. Paramera basal excavation never reaching paramera sides on dorsal view ( Figure 18 View Figure 18 ). Females sixth ventrite ‘ u ’ shape emargination having 1/3 of ventrite length ( Figure 18 View Figure 18 (e-f)) ................................................. ........................................ Dichotomius (Cephagonus) socius (Luederwaldt) View in CoL ( Figure 18 View Figure 18 )

8. Pronotal margin smooth after median lateral pit ................................................................ 9

8 ʹ. Pronotal margin serrated after median lateral pit ............................................................. 11

9. Pronotum anterior portion bearing deeply impressed fine punctures (some semiocellate punctures also present). Males cephalic horn emarginated at apex ................. ...................................................... Dichotomius (Cephagonus) fissus (Harold) View in CoL ( Figure 19 View Figure 19 )

9 ʹ. Pronotum anterior portion lacking distinct puncturesı at most having few fine and weakly impressed punctures. Males cephalic horn emarginated or not at apex. 10

10. Male cephalic horn emarginated producing two tubercle at each apex. Anterior portion of pronotal disc with a pair of acute tubercles. Pronotum posterior margin lacking ocellate punctures. Elytral striae with distinct punctures. Peruı Colombia and Western Equador........................ Dichotomius (Cephagonus) fonsecae (Luederwaldt) View in CoL ( Figure 21 View Figure 21 )

10 ʹ. Males cephalic horn conical with rounded apexı lacking emarginations. Anterior portion of pronotal disc with single-rounded lobe. Pronotum posterior margin having one or two rows of ocellate puncture. Elytral striae lacking distinct punctures. French Guiana and Suriname................................................................................................... ............................................... Dichotomius (Cephagonus) seag View in CoL new species ( Figure 25 View Figure 25 )

11. Elytra interstriae disc with striated microsculpture (30 x) that gives silky aspect to elytra on naked eye ( Figure 13 View Figure 13 (c-e)). Males cephalic carina longer than wide with rounded apex. Pronotum posterior margin with a single row of small ocellate puncture usually spaced by their diameter ( Figure 22 View Figure 22 (a)) ................................................... .......................................... Dichotomius (Cephagonus) baiano View in CoL new species ( Figure 22 View Figure 22 )

11 ʹ. Elytra interstriae disc lacking microsculptureı shiny ( Figure 13 View Figure 13 (a)). Males cephalic carina larger than taller or as wide as longı with rounded or slightly emarginated apex ( Figures 23 View Figure 23 (a)ı 24(a)). If cephalic carina with simple-rounded apexı then continuous coarse ocellate punctures present on anterior portion of pronotum. Pronotum posterior margin bearing 2 – 3 rows of coarse ocellate and/or elliptical punctures (as in Figure 14 View Figure 14 (c-d)) ............................................................................................. 17

12. Larger males pronotum with strong anterior excavationı taking half of the pronotum lengthı filled with coarse and dense puncture; anterior portion of pronotal disc having four lobes. Anterior portion of the females pronotum with well-defined coarse puncture. Northeastern Atlantic Forest in the states of Alagoası Paraíba and Pernambuco ........ Dichotomius (Cephagonus) filgueirasi View in CoL new species ( Figure 24 View Figure 24 )

12 ʹ. Males pronotum lacking wide excavationı punctures restricted to the anterior pronotal border; anterior portion of pronotal disc having two lobes. Anterior portion of the females pronotum will wrinkled striation and coarse punctures. Interior ‘ Agreste ’ Forests in the state of Pernambuco ........................................................... .......................... Dichotomius (Cephagonus) fernandosilvai View in CoL new species ( Figure 23 View Figure 23 )

13. Female cephalic carina with acute pair of tubercles. Sides of abdominal ventrites glabrous. Distance of triangular projections on females sixth ventrite equal to 1/3 of ventrite length ( Figure 9 View Figure 9 (b)). Paramera very longı having twice the length of phalobasis ( Figure 46 View Figure 46 (e)). West of the state of Rio Grande do Sulı Brazil...................... .......................... Dichotomius (Cephagonus) lucianomourai View in CoL new species ( Figure 46 View Figure 46 )

13 ʹ. Female cephalic carina produced in a single tubercle. Sides of abdominal ventrites with 1 – 10 ocellate setigerous punctures. Distance of triangular projections on females sixth ventrite from 1/10 ( Figure 9 View Figure 9 (c-d)) to 1/3 ( Figure 9 View Figure 9 (b)) of ventrite length. Paramera having at most the sub-equal length of phalobasis. Other distributionı Brazilian Atlantic Forest ......................................................................................... 14

14. Larger males reaching 20 mm. Females sixth ventrite emargination narrow (1/10 of sixth ventrite length) ( Figure 9 View Figure 9 (c-d)) and elytra with strong blue sheen near basis ( Figure 13 View Figure 13 (b)). Paramera having longitudinal excavation ( Figure 45 View Figure 45 (cıe)). Restricted to higher altitudes in the municipality of Itatiaiaı state of Rio de Janeiro ..................... ............................... Dichotomius (Cephagonus) itatiaiaensis View in CoL new species ( Figure 45 View Figure 45 )

14 ʹ. Larger males reaching 17 mm. Females sixth ventrite emargination narrow (1/3 of sixth ventrite length) ( Figure 9 View Figure 9 (b)) and elytra lacking blue sheen near basis. Paramera lacking longitudinal excavation ( Figure 43 View Figure 43 (cıe)). Also occurring in Itatiaia- RJ but with wider distribution in the states of RJı SPı PRı SC and RSı Brazil.................. ............................... Dichotomius (Cephagonus) spadiceus (Luederwaldt) View in CoL ( Figure 43 View Figure 43 )

15. Pygidium bearing ocellate punctures near anterior margin (basis). Chapada dos Guimarãesı state of Mato Grossoı Brazil...................................................................................... ................................ Dichotomius (Cephagonus) ingens (Luederwaldt) View in CoL ( Figure 41 View Figure 41 (a))

15 ʹ. Pygidium lacking ocellate puncturesı at most having very fine punctures (viewed under 20x magnification) (as in Figure 8 View Figure 8 (b))... ............................................................... 16

16. Posterior portion of pronotal disc bearing ocellate punctures. Elytral striae widenedı lacking distinct punctures. Chapada dos Parecis in the state of Mato Grossoı Brazil................ Dichotomius (Cephagonus) paresi Nunes & Vaz-de-Mello ( Figure 41 View Figure 41 (c))

16 ʹ. Pronotal disc lacking ocellate puncturesı those being sometimes restricted to posterior marginı anterior angles and/or to the anterior excavation. Elytral striae narrow and always bearing distinct punctures all over its extension (as in Figure 13 View Figure 13 (a)) ....................................................................................................................................................... 17

17. Cephalic carina surface wrinkled (striated). Anterior excavation of pronotum bearing coarse punctures. Chapadão do Céuı Goiás stateı Brazil............................................... ............ Dichotomius (Cephagonus) darwini Nunes View in CoL & Vaz-de-Mello ( Figure 41 View Figure 41 (b))

17 ʹ. Cephalic carina lacking striation. Anterior excavation of pronotum bearing at most fine punctures (20 x) .................................................................................................................... 18

18. Clypeo-frontal horn carinateı strongly transverseı widely emarginated at the apex and producing two tubercles at each apex. On smaller individualsı cephalic horn not producing lateral tubercles but still with a conspicuous emargination at apex. Smaller species (maximum BL: 19.5 mm; maximum PW: 13 mm). Descalvado Municipalityı São Paulo stateı Brazil.............................................................................................. ........... Dichotomius (Cephagonus) periotoi Nunes View in CoL & Vaz-de-Mello ( Figure 41 View Figure 41 (e))

18 ʹ. Clypeo-frontal horn carinate but not strongly transverseı lacking emargination and tubercles at the apex. Females and smaller individuals unknown. Larger species (maximum BL: 25 mm; maximum PW: 14 mm). Serra da Canastraı Southwest of Minas Gerais stateı Brazil.................................................................................................................... ............... Dichotomius (Cephagonus) manni Nunes View in CoL & Vaz-de-Mello ( Figure 41 View Figure 41 (d))

19. Males pronotum with coarse ocellate punctures at the mid-anterior portion; clypeogenal angle very obtuse (120³) ......................................................................................................... Dichotomius (Cephagonus) candango View in CoL new species ( Figure 35 View Figure 35 (f-i)) (the female of this species is unknown to us).

19 ʹ. Pronotum lacking coarse ocellate punctures at the mid-anterior portion; clypeogenal angle obtuse in females (110 to 120³) and usually straight or sub-straight (around 90³) on males ................................................................................................................ 20

20. Male cephalic process produced in a single weak knob; female cephalic process absent. Posterior margin of pronotum with at least a row of rounded ocelate punctures and other row of elliptical punctures. Elytral interstriae 2 and 5 – 7 (humeral callus) with strong transverse striation mainly visible near elytral basis. Bolivia: Santa Cruz ................................................................................................................................ .......................... Dichotomius (Cephagonus) edmondsi View in CoL new species ( Figure 37 View Figure 37 (a-d))

20 ʹ. Male cephalic process produced in a single tubercleı conical horn or transverse carinaı female cephalic process absent or produced in a low transverse carina having or not tubercles. South America (including Bolivia) and Panama............. 21 21. Males horn produced in a cephalic carina with a medial ‘ blade-like ’ tooth ( Figure 32 View Figure 32 (g)). Female cephalic process produced in a transversal carina with a pair of acute tubercles. Panama.... Dichotomius (Cephagonus) aielloae Nunes View in CoL ( Figure 32 View Figure 32 (f-h))

21 ʹ. Males horn absentı conicalı or if produced in a carinaı not truncated and lacking medial tooth on it. Female cephalic process absentı a single tubercle or produced in a cephalic carina having or lacking acute tubercles. Other localities south to Panama.............................................................................................................................................. 22

22. Male head surface with equally spaced fine punctures spaced by 1-twice their diameter; female head with continuous equally spaced fine punctures behind interocular space. Posterior margin of females pronotum with a row of ocellate punctures type II ( Figure 14 View Figure 14 (c)). Males pronotum declivity restricted to the anterior border; anterior portion of the disc having a pair of weak lobes. Brazil (MTı PAı RO) and Peru (Madre de Dios) ................................................................................................................. .................................... Dichotomius (Cephagonus) asenjoi View in CoL new species ( Figure 33 View Figure 33 (e))

22 ʹ. Male head surface smooth (at most with some striations and fine punctures near eyes and genae); female head with fine punctures restricted to the external border of the eyes. Posterior margin of females pronotum with 1 – 3 rows of coarseı elliptical or ocellate puncture type I ( Figure 14 View Figure 14 (b-d)). Males pronotum declivity widerı taking usually more than 1/3 of pronotum longitudinal length; anterior portion of the disc having 1 – 4 lobes. South America ................................................... 23

23. Elytra interstriae disc chagrinatedı 1st interstriae with differential shiny. Strong ocellate punctures present on the posterior border of pronotum. Areas above 800 m in the state of São Paulo ..................................................................................................... ...................... Dichotomius (Cephagonus) semicircularis (Luederwaldt) View in CoL ( Figure 30 View Figure 30 )

23 ʹ. Elytra interstriae disc smoothı if chagrinated then the 1st interstriae with similar shiny. Ocelate punctures on the posterior border of pronotumı lacking or weakly or strongly impressed. South America (including lower and higher altitudes in the state of São Paulo) ....................................................................................................................... 24

24. Males paramera with sub-apical spine (as in Figure 28 View Figure 28 (d)) (visible dorsally and ventrally). Larger males having 1 – 2 lobes at the anterior portion of the disc... 25

24 ʹ. Males paramera lacking sub-apical spine. Larger males lacking lobesı having central emargination or having 1 – 2 lobes at the anterior portion of the disc ................... 29

25. Paramera abruptly narrowed towards apex after sub-apical spine; apexes convergent. Bolivia.................. Dichotomius (Cephagonus) fissiceps (Felsche) View in CoL ( Figure 28 View Figure 28 )

25 ʹ. Paramera not narrowed towards apex or slightly narrowedı but apexes never convergent – parallel. South America .................................................................................. 26

26. Paramera narrowed at mid-portion (ventral and dorsal view) ( Figure 39 View Figure 39 (b-c)). Males with a single-rounded lobe on the anterior portion of the pronotal disc. Brazil (Goiás) .......... .......... Dichotomius (Cephagonus) emas View in CoL new species ( Figure 39 View Figure 39 (a-d))

26 ʹ. Paramera not narrowed at mid-portion (straight in ventral and dorsal view). Larger males with 1 – 2 lobes on the anterior portion of the pronotal disc. Brazilı Paraguay............................................................................................................................................ 27

27. Paramera lateral excavation near the junction with phalobasis ( Figures 2 View Figure 2 (a)ı 39(i)) taking 1/4 of paramera lateral length. Paramera having 1/3 the lateral length of phalobasis. Argentinaı Boliviaı Brazil (DFı GOı MGı MSı MTı SP) and Paraguay............ ................................................. Dichotomius (Cephagonus) reichei (Harold) View in CoL ( Figure 31 View Figure 31 ) 27 ʹ. Paramera lateral excavation near the junction with phalobasis taking 1/2 of paramera lateral length (as in Figure 39 View Figure 39 (i)). Paramera having 1/2 the lateral length of phalobasis. Brazil (MTı CE) ......................................................................................................... 28

28. Paramera longitudinal excavation with chagrinated microsculpture (viewed under 30x magnification); sub-apical spine strongly produced; sub-apical spine delimiting paramera apical narrowing. Larger males with ill central lobe on the anterior portion of the pronotal discı never as developed as the lateral lobes. Brazil (CE) ..... .............................. Dichotomius (Cephagonus) paschoali View in CoL new species ( Figure 39 View Figure 39 (i-l))

28 ʹ. Paramera longitudinal excavation with fine punctures and smooth sculpture (viewed under 30x magnification); sub-apical spine weakly produced; paramera not narrowed apically. Larger males with strong central lobeı more developed than the lateral lobes or produced in a bifurcated lobe. Brazil (MT) ............................... .............................. Dichotomius (Cephagonus) barbarae View in CoL new species ( Figure 33 View Figure 33 (i-l))

29. Paramera apexes divergent or parallelı truncatedı not flattened ............................. 30

29 ʹ. Paramera apexes convergentı roundedı flattened... .................................................... 32

30. Paramera strongly narrowed medially (dorsal and ventral view). Brazil (DF)... ......... ............................ Dichotomius (Cephagonus) frizzasae View in CoL new species ( Figure 37 View Figure 37 (e-h))

30 ʹ. Paramera nor narrowed medially. Brazil (MT) ................................................................... 31

31. Paramera with strong knob anterior to basal excavation ( Figure 38 View Figure 38 (g)); basal excavation having striated microsculpture (15x). Brazil (MTı Diamantino) ................... ............................... Dichotomius (Cephagonus) furtadoi View in CoL new species ( Figure 38 View Figure 38 (e-i))

31 ʹ. Paramera at most having a protuberance anterior to basal excavation; basal excavation lacking striated microsculpture. Brazil (North of the state of Mato Grosso) ...................................................................................................................................................... ............ Dichotomius (Cephagonus) marcoscarvalhoi View in CoL new species ( Figure 39 View Figure 39 (e-h))

32. Paramera having longitudinal excavation (as indicated in Figure 33 View Figure 33 (dıj-l)) .......... 33

32 ʹ. Paramera lacking longitudinal excavation (as in Figures 2 View Figure 2 and 32 View Figure 32 (b-d)) ............... 36

33. Longitudinal excavation having a longitudinal carina ( Figure 35 View Figure 35 (e)). Brazil (RR)ı Venezuela..... Dichotomius (Cephagonus) blancoi View in CoL new species ( Figure 35 View Figure 35 (a-e))

33 ʹ. Longitudinal excavation lacking longitudinal carina. South America ..................... 34

34. Males pronotum lacking punctures on the posterior border of pronotum (at most some near posterior angles). Body elongatedı sides of elytra subparallel. Paramera ventral central excavation lacking sclerotised parts – membranous. Boliviaı Peru.... ............................... Dichotomius (Cephagonus) arnaudi View in CoL new species ( Figure 33 View Figure 33 (a-d))

34 ʹ. Pronotum having punctures (continuous or not) on the posterior border of pronotum. Body more ovalı elytra sides curvedı not sub-parallel. Paramera ventral excavation totally sclerotised or having carinas or other sclerotised portions delimiting the excavation ................................................................................................................................ 35

35. Larger males cephalic horn conical; smaller males and females bearing a bifurcated low cephalic carina. Larger males pronotum with a central lobe on the anterior portion of the disc; anterior excavation and pronotum declivity wide (equal to 1/3 the pronotum longitudinal length); smaller males and females pronotum simply convex – posterior border of pronotum having continuous punctures. Paramera excavation narrowı restricted to paramera apical third. Brazil (MT) ................................. ...................... Dichotomius (Cephagonus) ricardosilvai View in CoL new species ( Figure 40 View Figure 40 (a-d)) 35 ʹ. Males cephalic conical or produced in a tubercleı females cephalic carina as above. Larger and smaller males pronotum with a pair of weak knobs on the anterior portion of the disc; anterior excavation and declivity taking less than 1/5 of the pronotum longitudinal length. Paramera excavation wideı taking almost all paramera length in lateral and dorsal view. French Guiana.......................................................... ....................................... Dichotomius (Cephagonus) feeri View in CoL new species ( Figure 38 View Figure 38 (a-d))

36. Males head with protuberantı rounded and folded-upward clypeo-genal junction. Males pronotum with wide central emargination on the anterior portion of the disc (wider than eyes distance). Posterior border of pronotum having continuous punctures. Paramera with wide lateral excavationı taking half of the paramera length in lateral view. Brazil (RJı SP (both above 1000 m) and SC) .................................. ................................... Dichotomius (Cephagonus) quadraticeps (Felsche) View in CoL ( Figure 26 View Figure 26 )

36 ʹ. Males head lacking protuberant clypeo-genal junction. Males pronotumı if with emarginationı narrowı never as wide as eye distance. Posterior border of pronotum lacking or having punctures. Paramera lacking wide lateral excavation ............... 37

37. Larger males pronotum with two weak lobes on the anterior portion of the disc. Paramera lacking excavations (dorsal and lateral view)ı with subtle declivity in lateral view; paramera not flattened at apical third. Argentinaı Boliviaı Peru.............. ...................... Dichotomius (Cephagonus) clypeatus (Luederwaldt) View in CoL ( Figure 32 View Figure 32 (a-e))

37 ʹ. Larger males pronotum with a strong central-rounded lobe on the anterior portion of the disc or having a narrow emargination on it. Paramera having basal excavationsı with abrupt declivity in lateral view; paramera strongly flattened in dorsal view. Brazil and Peru.................................................................................................................... 38

38. Larger males pronotum with strong central lobe on the anterior portion of the disc; smaller males pronotum simply convex. Smaller males elytra interstriae chagrinated (as in Figure 13 View Figure 13 (f-g)). Paramera strong flattened apically; subgenital plate taking the whole ventral portionı not reduced. Brazil (MT) ................................................. .............................. Dichotomius (Cephagonus) tissianiae View in CoL new species ( Figure 40 View Figure 40 (f-i))

38 ʹ. Males pronotum with central emargination on the anterior portion of the disc (emargination never wider than eyes distance). Elytra interstriae with smooth microsculpture. Paramera flattened in dorsal view but not as above; subgenital plate narrowı taking only part of the ventral portion and leaving membranous portions visible ventrally. Brazil (MTı PA)ı Peru (Madre de Dios) ....................................... ................................ Dichotomius (Cephagonus) gardneri View in CoL new species ( Figure 37 View Figure 37 (i-l))

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Scarabaeidae

Genus

Dichotomius

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