Dichotomius (Selenocopris) woodruffi Solís and Kohlmann, 2022

Solís, Ángel & Kohlmann, Bert, 2022, Dichotomius woodruffi, a new Dichotomius species of the agenor group from Costa Rica and Nicaragua (Coleoptera: Scarabaeidae: Scarabaeinae), Insecta Mundi 2022 (918), pp. 1-12 : 3-8

Dichotomius (Selenocopris) woodruffi Solís and Kohlmann , new species

( Fig. 1–11 , 19 )

Dichotomius agenor (Harold, 1869) – Kohlmann and Solís 1997: 345; Kohlmann et al. 2007: 30; Solís and Kohlmann 2012: 6.

Dichotomius enioi Montoya-Molina and Vaz-de-Mello, 2021 (in part): 25.

Type depository. Holotype male, allotype female and 210 (88♀, 122♂) paratypes in MNCR, 2 (1♀, 1♂) paratypes in FSCA, and 4 (3♀, 1♂) paratypes in ASC.

Type status. Holotype male, type labels: “ COSTA RICA: Puntarenas Prov. Est. Q. Bonita. 50 m, agos 1993, R. M. Guzmán. L N 194500_469850 #2297. INBIO CRI001 969440”. “ HOLOTYPE / Dichotomius / woodruffi n. sp. / Solís & Kohlmann ded. 2022 [printed, red]”.

Paratypes (89♀, 122♂). Allotype, female, type labels. “ COSTA RICA: Puntarenas Prov. Est. Q. Bonita. 50 m, Res. Biol. Carara. May 1992. J.C. Saborío. L-N194500-469850. INBIO CRI000 796048”. “ ALLOTYPE / Dichotomius / woodruffi n. sp. / Solís & Kohlmann ded. 2022 [printed, red]”. Puntarenas Prov. Est. Q. Bonita. 50 m, Res. Biol. Carara. May 1992. J.C. Saborío. L-N194500-469850. INBIO CRI000 796048”. “ ALLOTYPE / Dichotomius / woodruffi n. sp. / Solís & Kohlmann ded. 2022 [printed, red]”. “ COSTA RICA: Guanacaste Prov. Area de cons. Arenal. Río San Lorenzo, Tierras Morenas. 10.610459 N, − 84.994969 W. 01 jul 1994. Col. Rodríguez, G. ” (1 ♀); with same data as previous but “Tierras Morenas. 10.5710619 N, − 85.025949 W. 01 may 1994. Col. Rodríguez, G. ” (4 ♀, 2♂); with same data as previous but “ Río San Lorenzo, Tierras Morenas. 10.610459 N, − 84.994969 W. 01 jul 1994. Col. Rodríguez, G. ” (10 ♂); with same data as previous but “Área de cons. Guanacaste. La Cruz, La Garita, Est Los Almendros. 11.033856 N, − 85.524789 W. 28 jul 1992. Col. López, E. ” (1 ♂); with same data as previous but “ Puntarenas Prov. Area de cons. Osa. Golfito, Pque Nal Corcovado, Est Agujas , Las Quebraditas. 8.5226319 N, − 83.48411 W. 03 may 2002. Col. Azofeifa A. ” (2♀, 1 ♂); with same data as previous but “La Bonanza, entre Agujas y Cerro Rincón. 8.5304219 N, − 83.449049 W. 17 jun 2008. Col. Hernández, B. ” (2♀, 3 ♂); with same data as previous but “ Osa. P.N. Corcovado. Est. Agujas . 8.536614 N, − 83.42551 W. 12 abr 2000. Col. Azofeifa A. ” (1 ♀); with same data as previous but “Area de cons. Pacifico Central. Garabito, Reserva Biol. Carara, Est. Quebrada Bonita. 9.7674529 N, − 84.608119 W. 01 jul 1990. Col. Bello, E. ” (1♀, 2 ♂); with same data as previous but “ 01 may 1992. Col. Saborío, J.C. ” (15♀, 15 ♂); with same data as previous but “ 01 jun 1992. Col. Saborío, J.C. ” (4♀, 8 ♂); with same data as previous but “ 01 jul 1992 ”. (6♀, 5 ♂); with same data as previous but “ 01 jul 1992. Col. Guzmán, R. ” (6 ♀, 6 ♂); with same data as previous but “ 10 ago 1992.” (1♀, 2 ♂); with same data as previous but “ 01 set 1992. Col. Saborío, J.C. ” (1 ♂); with same data as previous but “ 02 set 1992. Col. Guzmán, R. ” (4♀, 3 ♂); with same data as previous but “ 18 oct 1992.” (3♀); with same data as previous but “ 01 nov 1992. Col. Saborío, J.C. ” (3 ♀, 1 ♂); with same data as previous but “ 01 may 1993. Col. Saborío, J.C. ” (3 ♀, 17 ♂); with same data as previous but “ 01 jun 1993.” (2 ♂); with same data as previous but “ 01 jun 1993. Col. Guzmán, R. ” (4 ♂); with same data as previous but “ 01 jul 1993. Col. Saborío, J.C. ” (2♀); with same data as previous but “ 01 jul 1993. Col. Guzmán, R. ” (1 ♀); with same data as previous but “ 01 ago 1993. Col. Saborío, J.C. ” (2♀, 4 ♂); with same data as previous but “ 01 ago 1993. Col. Guzmán, R. ” (2 ♀, 9 ♂); with same data as previous but “ 01 set 1993.” (2 ♀, 2 ♂); with same data as previous but “ 01 abr 1994.” (1 ♂); with same data as previous but “ 01 set 1994.” (2 ♀, 1 ♂); with same data as previous but “ 01 oct 1994. Col. Saborío, J.C. ” (1♀); with same data as previous but “ 01 oct 1994. Col. Guzmán, R. ” (8 ♀); with same data as previous but “ 01 nov 1994. Col. Saborío, J.C. ” 1 ♀); with same data as previous but “ 01 jul 1995. Col. Guzmán, R. ” (1♀, 1 ♂); with same data as previous but “ 01 ago 1995.” (1 ♀, 2 ♂); with same data as previous but “ 01 may 1996.” (1 ♂); with same data as previous but “Area de cons. Tempisque. Lepanto, Karen Morgensen, Sendero Principal. 9.8670949 N, − 85.05995 W. 20 set 2003. Col. Cárdenas, Yow.” (1♀, 2 ♂); with same data as previous but “ 23 jun 2003. Col. Briceño, Duvalier.” (1♀); with same data as previous but “ 22 jun 2003. Col. Porras Vega, Wendy.” (3 ♂); with same data as previous but “Send. Central. Est. San Miguel. 9.5839859 N, − 85.11212 W. 22 abr 1997. Col. Alvarado, F. ” (1 ♂); with same data as previous but “Area de cons. La Amistad Pacifico. Parcelas IDA. 8.958083 N, − 83.05217 W. 10 jun 2008. Col. Pulido, A. ” (2 ♂); with same data as previous but “ San José Prov. Area de cons. Pacifico Central. Est. Bijagual, 600 m. N de Bijagualito. 9.7430889 N, − 84.544759 W. 01 jul 1995. Col. Saborío, J.C. ” (6 ♀, 4 ♂); with same data as previous but “ P. N. La Cangreja, Puriscal, Chires. 9.690711 N, − 84.377529 W. 28 jun 2005. Col. Hernández, B. ” (2 ♀, 3 ♂); with same data as previous but “ 800 m al N. de Bajo La Palma. 9.7630379 N, − 84.244929 W. 22 may 1995. Col. Solis, A. ” (3♂). All paratypes deposited in MNCR. “ NICARAGUA: Managua Dep. El Crucero, Reserva privada El Bajo, Sendero Quebrada, 730– 597 m. 11.991915 N, − 86.322757 W. 26–27 nov 2019. Col. Hernández, B. ” (4♀, 2 ♂, paratypes deposited in ASC and FSAC) .

Other examined material (106 specimens, non-paratypes, material identified by AS, not mounted, and preserved in alcohol at MNCR). Their locality data is the following: “ COSTA RICA: Guanacaste Prov. Area de cons. Guanacaste. Camino del Aguacate , Est. La Perla , 375 m, Pitfall T. 28 al 30 junio de 2017, A. Solís, E Cantillano, J. Cortez, Coord. 10.771236, −85.428981 ” (25 unverified sex); with same data as previous but “ Bosque Húmedo en Sector Santa Rosa , ACG, 300 m, Pitfall T. 8 al 10 de junio 2016, A. Solís, Coord. 10.851171, −85.606955 ” (35 unverified sex); with same data as previous but “Área de cons. Tempisque. Bagaces, Est. Palo Verde. 10.35 N, − 85.352779 W. 14 nov 2004. Col. Gamboa R. B. ” (1 ♂); with same data as previous but “ Puntarenas Prov. Bosque de Asentamiento de INDER en Sansi, SINAC, 500 m, Pitfall T. 13 al 15 junio 2013, A. Solís y C Godínez, Coord. 8.959002, −83.052355 ” (20 unverified sex); with same data as previous but “ La Bonanza, sendero entre Agujas y Cerro Rincón, Parque Nacional Corcovado, 400 a 600 m, Pitfall T. 17 al 19 junio 2008, B. Hernández y M. Moraga, Coord. 8.530277, −83.4488 ” (14 unverified sex); with same data as previous but “ La Cangreja, Zona Protectora Cerro de La Cangreja , 600 m. 9.69916 N, − 84.37750 W. Pitfall T. 29 jun 2005, Col. B. Hernández ” (11 unverified sex) .

Distribution. Costa Rica (Guanacaste, Puntarenas, and San José provinces) and Nicaragua (Managua department) ( Fig. 19 ).

Etymology. Dichotomius woodruffi new species is an eponym after the late Robert Woodruff, a scarabaeodologist, known for his work on Florida Scarabaeidae , especially dung beetles and the melolonthine genus Phyllophaga . He was also interested in collecting postage stamps with scarabs depicted on them.

Diagnosis. Dichotomius woodruffi new species is separated from other species in the D. agenor species-group by the following combination of characters: Male interocular surface with lightly shagreened microsculpture (small, lightly impressed punctures) ( Fig. 1 ). Anterior pronotal border medially sinuate in major males ( Fig. 6 ); anterior pronotal declivity with a medial sulcus ( Fig. 7 ); male median tubercle conical, without apical emargination, twice as high as lateral tubercle; lateral tubercles with acute apex ( Fig. 3 ). Female fronto-clypeal carina quadrituberculate ( Fig. 4 ). Ventral clypeal process spiniform ( Fig. 5 ). Row of dense uninterrupted ocellate punctures arranged along anterior and posterior margin of pronotum ( Fig. 6 ). Interstriae with surface shagreened ( Fig. 1–2 ). Pygidium twice as wide as long ( Fig. 8 ). Setigerous lateral areas on the anterior and lateral lobes of metasternum interrupted at the posteromedial mesocoxal margins. Ventral surface of profemur covered with well-impressed punctures, setigerous setae near the medial edge. Ventral surface of metafemur without setose punctures.

Description. Holotype male. Length 23.0 mm. Width 13.5 mm. Dorsal surface black and shagreened ( Fig. 1 ).

Head and pronotum shiny, elytra and pygidium dull. Head with the anterior dorsal surface crosswise rugose, rugosity irregular. Transverse tubercle wide and flattened fronto-posteriorly ( Fig. 3 ), with a simple conical central process or horn and two lateral carinae whose profile in frontal view is acute at the lateral angles and sinuous in the upper part ( Fig. 3 ). Punctures decrease in size and depth as one advances from the clypeus up the slope and the upper part of the transverse forehead, where they almost disappear. Vertical posterior area of the transverse tubercle shows punctures in the form of small transverse lines. Horizontal posterior area of the head shows small transverse punctures in the lateral area, central area devoid of punctures. Anterior clypeal border with two teeth separated by an obtuse indentation. Ventral clypeal process spiniform ( Fig. 5 ).

Pronotum wider than long with a pronounced slope in the anterior area and with a slight central concavity, a slight elevation on each side and another slight bilobed elevation in the upper part of the concavity. The surface of the pronotum possesses fine, small, simple punctures in the central disc area than in the lateral area. Punctures near the anterior and posterior margin are ocellate. Anterior pronotal border medially sinuate ( Fig. 6 ); anterior pronotal declivity with a fine sulcus in its upper part ( Fig. 7 ).

Elytral striae with ocellate punctures. Interstriae with very small, almost imperceptible punctures.

Pygidium twice as wide as long ( Fig. 8 ); with very small punctures throughout most of its surface except for a row of strongly impressed ocellate punctures bordering the basal margin.

Ventral area. The entire ventral surface, as well as the dorsal surface, with shagreened micro-sculpture. Area of the hypomeron with the anterior and posterior third covered with setigerous punctures strongly impressed with long setae, central area smooth without setigerous punctures except for one, two or three rows of setigerous punctures near the lateral border (4 or 5 rows in D. enioi ).

Prosternal surface lacking obvious punctures. Mesosternum with setaceous, ocellate punctures; setae minute. Mesepimeron and metepisternum densely covered with setigerous, ocellate punctures. Metasternum with lateral lobes covered with setigerous punctures, anterior central lobe with ocellate setigerous punctures strongly impressed in the anterolateral areas. Central and posterior area of metasternum, including the area adjacent to the posterior border of the mesocoxa, without setigerous punctures.

Abdominal ventrites with one (more frequently two) row of ocellate punctures in the area near the anterior border.

Ventral surface of profemora with small and shallow punctures medially (surface appearing rugose), with large setigerous punctures very strongly impressed in the posterior distal region. Ventral area of the meso- and metafemora smooth, with minute punctures (almost invisible) except in the most distal region.

Posterior coxa with a row of setigerous annular punctures along the entire length and contiguous to the posterior border.

Parameres and lamella copulatrix as in Figures 9–11 .

Allotype female. Length 19.0 mm. Width 13.0 mm. As male except for the following characters: Head with the entire dorsal surface crosswise rugose, the rugosity is irregular and most strongly impressed on the clypeus ( Fig. 2 ). Transverse, quadrate elevation in the surface of the forehead. Two central tubercles a little higher and connected to each other by a small, curved carina forming a concavity posteriorly ( Fig. 4 ). Less developed males are like females in the characteristics of the dorsal area of the head.

Pronotum without declivity as in the holotype but with a slight elevation in the anterior discal area, like intermediately developed males and nearly absent in less-developed females. Punctures always more strongly impressed in less developed females.

Morphological variation (paratypes). Length 17.0–23.0 mm. Width 10.5–13.5 mm. Anterior edge of the pronotum of males varies from very wide (majors) to less wide (minors). The anterior declivity of the pronotum is wider in major males and decreases in amplitude until it is lacking in intermediate males (like females). Pronotum may vary from finely to coarsely punctate; females have coarser punctures. Minor males have the anterior pronotal border parallel and not sinuate. Minor males resemble females, especially regarding the cephalic carina. Male forms vary from minors to intermediates to majors.

The hypomeron in the central area may lack punctures or possess a few ring-like punctures without setae. Intermediately developed males with apex of the central process bituberculate and in less developed males the transverse elevation of the forehead like that of females. Ventral profemur surface varies from finely to coarsely punctate; females tend to possess coarser punctures. On its left side, one very well-developed female specimen was found to have setigerous punctures of the medial and lateral edges of the metasternum continuous at the inner mesocoxal area, but not on its right-side specimen possessed a convex pygidium.

Ecology. We collected this species in traps baited with human, pig, and horse dung. It is distributed in humid forests and piedmont forest areas along the Pacific slope in Costa Rica and southern Nicaragua. The species has been collected from April to November, from 0 to 800 m altitude.

Chorology. The known southern distribution limit of D. woodruffi new species is in Costa Rica near the border with Panama (8.9520000 −83.0345000), and the known northernmost distribution limit is at El Bajo Private Reserve near Managua, Nicaragua (11.991928 −86.322666). It is an uncommon species in the northern portion of its range, whereas it is prevalent in the southern portion and is allopatric with D. centralis . The known northern range limit for D. agenor is Veraguas, Panama (8.1996830 −81.2343500), thus separating populations of D. agenor and D. woodruffi new species by approximately 200 km.

Taxonomic remarks. Montoya-Molina and Vaz-de-Mello (2021) reported six specimens of D. enioi in Santa Rosa, Guanacaste Province and in the Quebrada Bonita Station in the Carara Biological Reserve in Puntarenas Province along the Pacific coast of Costa Rica. We examined specimens from these same localities, but we recorded the presence only of D. woodruffi new species. (35 specimens from Santa Rosa and 152 specimens from Quebrada Bonita). We have recorded no specimens of D. enioi in Costa Rica or Nicaragua. Instead, we have recorded only D. centralis and D. woodruffi new species in Costa Rica and Nicaragua ( Fig. 19 ). Substantial evidence is here presented for the species concept ( D. woodruffi new species). As indicated earlier, Montoya-Molina and Vaz-de-Mello (2021) seem to have confused D. enioi specimens with D. centralis . These species are separated based on the following characteristics, in the case of D. enioi: Ventral clypeal process truncate ( Fig. 16 ); male anterior pronotal border simple, not medially sinuate ( Fig. 17 ); setigerous lateral areas on the anterior and lateral lobes of metasternum continuous at the posteromedial mesocoxal margins; male pygidium less than twice as long as width, strongly convex ( Fig. 18 ); it is distributed in Guatemala and Mexico. Whereas D. woodruffi new species is characterized by: Ventral clypeal process spiniform ( Fig. 5 ); male anterior pronotal border medially sinuate ( Fig. 6 ); setigerous lateral areas on the anterior and lateral lobes of metasternum interrupted at the posteromedial mesocoxal margins; male pygidium more than twice as long as width, slightly convex ( Fig. 8 ); it is distributed in Costa Rica and Nicaragua.

Figures

Figure 19. Known distribution of Dichotomius agenor, D. centralis, and D. woodruffi new species in Nicaragua, Costa Rica, and Panama.

Figures 1–6. Dichotomius woodruffi, new species. 1) Dorsal habitus, holotype, male. Scale bar equals 1 cm. 2) Dorsal habitus, allotype, female. Scale bar equals 1 cm. 3) Frontal view, holotype, male. 4) Frontal view, allotype, female. 5) Ventral clypeal process spiniform, holotype male. 6) Anterior pronotal border (frontal view), holotype male.

Figures 7–12. Dichotomius woodruffi, new species, and D. centralis. 7–11) D. woodruffi. 7) Anterior pronotal sulcus (lateral-oblique view), holotype male. 8) Male pygidium twice as broad as long, slightly convex, holotype male. 9) Lateral view of the aedeagus, holotype male. 10) Ventral view of the aedeagus, holotype male. 11) Lamella copulatrix, holotype male. 12) D. centralis, elytral stria crenulate.

Figures 13–18. Comparative structures of Dichotomius spp. 13) D. centralis anterior pronotal surface (lateraloblique view) subrugose, male pronotal anterior declivity with a medial carina. 14) D. agenor ventral clypeal process bilobed. 15) D. agenor female cephalic carina bituberculate. 16) D. enioi ventral clypeal process truncate. 17) D. enioi male anterior pronotal border simple, not medially sinuate. 18) D. enioi male pygidium less than twice as long as wide, convex.