Dichotomius (Dichotomius) compressicollis ( Luederwaldt, 1929 )

Dichotomius (Dichotomius) compressicollis ( Luederwaldt, 1929) View in CoL

( Figs. 25a, b View Figure 25 , 26 View Figure 26 a-m, 24b)

Pinotus compressicollis Luederwaldt, 1929: 125 View in CoL (original description)

Pinotus compressicollis View in CoL : Blackwelder (1944): 207 (citation); Contreras- Gacharná (1951): 222 (citation).

Dichotomius compressicollis View in CoL : Escobar (2000): 208 (citation); Medina et al. (2001): 138 (citation); Noriega-Alvarado (2004): 39 (citation); Pulido et al. (2007): 307 (citation); Medina and Pulido (2009): 59 (citation); Krajcik (2012): 91 (citation); Noriega (2012): 4 (citation); Noriega (2015): 182 (citation);Chamorro et al. (2019a): 38, 41 (citation and photography).

Dichotomius View in CoL compresicollis (incorrect subsequent spelling): Sarmiento-Garcés and Amat-García (2014): 106 (diagnosis), 110,113 (citation); 123 (photo); Cárdenas-Bautista et al. (2020): 823, 830, 836 (citation).

Dichotomius (Dichotomius) compressicollis View in CoL : Chamorro et al. (2018): 104 (citation); Chamorro et al. (2019b): 110 (citation).

Material examined: Lectotype [♂, here designated]: Labels: 1: {printed text on white label} Columbien / 2: {handwritten text on white label} Staudinger 1927 / 3: {printed text on red label with black margins} COTIPO / 4: {handwritten text on white label with black margins} Pinotus compressicollis gree. / 5: {printed text on white label} 17041 / 6: {printed text on white label} 800 [ MZSP] ( Fig. 25a, b View Figure 25 ) . Paralectotype [♀, here designated]: Labels: 1: {printed text on white label} Columbien / 2: {handwritten text on white label} Staudinger 1927 / 3: {printed text on red label with black margins} COTIPO / 4: {handwritten text on white label with black margins} Pinotus compressicollis gree. / 5: {printed text on white label} 17040 / 6: {printed text on white label} 800 [ MZSP] . Additional specimens: COLOMBIA: Boyacá: Santa Maria 4°51′N 73°16′W GoogleMaps 850m. Trampa de excremento de cerdo 21.x.2006 Arias, J. Delgado, P. & F. Molano. 1♀. [ UPTC] . Caquetá: Florencia Corpoicamacagual 1°37′N 75°36′W 275m Trampa Pitfall iii-iv.2004 Loaiza, Y. 1♀. [ UPTC] GoogleMaps . Cundinamarca: Medina Miralindo 4°35′33″N 73°23′17″W GoogleMaps 550 m II-II-1997 Ex. Hum Escobar F. 2♂ 1♀. [1♂ CEMT, 1♂ 1♀ IAvH-E]. Medina Alto del río Gazaunta Vereda Miralindo Q[ebra] da La Ardita . 550m. 4°35′N 73°23′W T GoogleMaps 1t 3 iii.1997 Escobar F. 1♂. [ UPTC] . Meta: Cumaral Finca Pavito 510 m XI-2001 colecta nocturna Noriega J. 3♀. [ CEMT]. Villavicencio Bosque de Bavaria 4°9′N 73°38′W GoogleMaps 550 m Pitfall ex. Hum. Noriega J. 1♂ 1♀. [ CEMT]. Puerto López El Naranjal 4°5′14″N 72°57′30″W GoogleMaps 220m II-97 Escobar F. 1♀. [IAvH-E]. El Dorado El Porvenir Bosque 3°42′20.64″N 73°32′36.42″W WGS84 336m T ExH 21.VIII.2013 Isaza L. 2♂ 5♀. [IAvH-E]. Rio Duda PNN Tinigua CIEM 2°40′N 74°10′W 350m TEH I.1996 Jiménez I. 1♂. [IAvH-E]. Villavicencio Agrícola El Naranjal carreera a Puerto Colombia 200m 4°2′N 73°15′W Bosque de Vega Trampa de excrement humano 19.x.2009 López D. 1♀. [ UPTC] GoogleMaps .

Putumayo: Puerto Leguizamo Núcleo Santander -0.127852 -74.616468 Forest 190m 01-IX-2019 Martínez, D.E. & Garcia, D. 1 unsexed individual. [IAvH-E], -0,13521 -74,597957 06-IX-2019. 1 unsexed individual. [IAvH-E]. [Valle del Cauca]: S.A. Felipe Ovalle, Q. Ac. 33501. 1♂ 1♀. [ CEMT]. ECUADOR GoogleMaps : Orellana: Dayuma Plataforma Primavera 300 m 21-XI-2011 Pitfall excremento Hernández C. 1♀. [ CEMT]. Francisco de Orellana Rodrigo Borja IAMOE 04-VI-2000 Pitfall heces humanas Dávalos A. 1♀. [ CEMT] . Pastaza: Vía Triunfo-Arajuno 13-VI-1998 Barragán A. 1♂. [ CEMT] . Sucumbios: Pacayacu Campo Libertador XII-2010 Pitfall excremento Colecta manual Gallo F. 1♂. [ CEMT]. PERÚ : Loreto: Río Pucacuro 9779176 N 04322797 W 203 msnm Bosque primario de terraza (tierra firme) 21-XI-2007 Pitfall carroña Moreno C. 1♂. [ CEMT], Pitfall heces. 1♂ 1♀. [ CEMT] .

Diagnosis: This species can be distinguished by the following combination of characters: (1) Males with clypeus projected giving the appearance of a triangular head, females without projection and oval head. ( Figs. 25 View Figure 25 , 26a View Figure 26 ). (2) Both sexes with transverse carina in the frons ( Figs. 25 View Figure 25 , 26a, b View Figure 26 ). (3) Both sexes with anterior angles of pronotum curved. (4) Protibial spur without angle near apex ( Fig. 26e View Figure 26 ). (5) Males pronotum with process giving triangular appearance, but anterior area straight and with two projections in posterior area ( Figs.25 View Figure 25 , 26a View Figure 26 ), females with simple pronotum ( Fig. 26b View Figure 26 ). (6) Lateral foveae of pronotum shallow in both sexes. (7) Meso-metaesternal suture not evident ( Fig. 26c View Figure 26 ). (8) Elytral striae bicarinate, not deep and with punctures separated by twice their diameter, sometimes inconspicuous in lateral striae. (9) Pygidium with complete apical margin and evident punctures ( Fig. 26f View Figure 26 ). (10) Male genital organ in lateral view with subquadrangular parameres and straight apex ( Fig. 26g View Figure 26 ). (11) Subgenital plate present ( Fig. 26I View Figure 26 ). (12) Shapes of endophallites ( Fig. 26 View Figure 26 j-m).

Redescription: Males: Length 12.4‒14.5 mm; width 7.7‒8.5 mm. Black and shiny color.

Head: Wider than long with subtriangular shape. Anterior margin is projected, clypeal teeth not evident ( Figs. 25a View Figure 25 , 26a View Figure 26 ). Clypeal surface strongly wrinkled. Clypeo-genal suture inconspicuous. Genae surface with wrinkles. Frons with transverse carina from 0.2-1mm long, with two lateral tips and curved central area (some specimens straight), surface around the carina without wrinkles but with ellyptic and weak punctures.

Thorax: Pronotum long than wider, with smooth and shiny appearance. Anterior angles long and curved, surface with scarce, shallow punctures ( Figs. 25a View Figure 25 , 26a View Figure 26 ). Disc of pronotum with process giving triangular appearance, with anterior area straight and with two projections in posterior area backwards directed ( Figs. 25a View Figure 25 , 26a View Figure 26 ). Lateral foveae inconspicuous. Hypomeron with shagreened surface, with ocellate and setigerous punctures separated by less than once their diameter in the anterior and lateral areas, central area is only shagreened and posterior area with ocellate punctures. Prosternum shagreened with setigerous punctures. Elytral striae bicarinate with shallow and ocellate punctures spaced by about twice times their diameter, sometimes inconspicuous in lateral striae. Elytral interstriae with shallow microsculpture giving shiny appearance and without punctures. Mesoventrite shagreened, with short setae. Central area with a smooth surface. Meso-metaesternal suture not evident ( Fig. 26c View Figure 26 ). Mesanepisternum shagreened with large setigerous punctures separated by less than once their diameter. Metaventrite with anterior lobe with microsculpture, shiny and with setae in lateral margins near to the insertion of coxa. Metaventrite sides with shagreened surface and denser setigerous punctures. Metanepisternum with similar surface to Mesanepisternum.

Abdomen: Shiny ventrites with microsculpture and one rows of ocellate punctures in the anterior area becoming two towards the side. Sixth ventrite strongly narrow medially. Pygidium shiny with microsculpture; with small and shallow punctures spaced by more than three times their diameter ( Fig. 26f View Figure 26 ). Pygidium with complete apical margin ( Fig. 26f View Figure 26 ).

Legs: Protibia with four lateral teeth.Protibial spur simple, without angle near apex going to the base of the fourth tarsomere ( Fig. 26e View Figure 26 ). Meso- and metatibia widened gradually towards apex; outer margin with eight to ten lateral spines, each with long erect setae; dorsal surface with two longitudinal rows of setae, apical side with setae throughout. Mesotibia with two spurs, unequal in length and acute apically. Metatibial spur apically truncate going to the base of the third tarsomere. Meso and metatibia with five tarsomeres, the first four sub-triangular, flattened dorsoventrally, inner edge with long continuous erect setae, outer edge with three to four setae, and the apices with tufts of setae.

Male genitalia: Lateral view of aedeagus with subquadrangular phallobase, basal area with a medium bulge on both sides, apex with a constriction of approximately 115°and a notch on the lower edge. Subquadrangular parameres and straight apex ( Fig. 26g View Figure 26 ). Dorsal view with symmetrical parameres with widened basis ( Fig. 26h View Figure 26 ). Central area with a constriction, widening apically. Apex of parameres curved. Ventral view with symmetrical parameres. Subgenital plate presente with small sclerites ( Fig.26i View Figure 26 ). Endophallites: ME is large, asymmetrical and sclerotized ( Fig. 26m View Figure 26 ). A+SA complex with undefined form, more sclerotized in the central area surrounded by a semi-sclerotized membrane ( Fig. 26k View Figure 26 ). SRP has “C” form, slender and with defined edges ( Fig. 26j View Figure 26 ). FLP has “n” shape with right lateral area sclerotized and left with semi-sclerotized membrane ( Fig. 26l View Figure 26 ).

Female: Length 11.5‒15.3 mm; width 6.7‒8.9 mm. Differs from male by presenting oval head, with clypeus without central projection ( Fig. 26b View Figure 26 ). Head carina is less pronounced ( Fig.26b View Figure 26 ). Pronotum is simple, convex and without process ( Fig 26b View Figure 26 ). Sixth abdominal ventrite not shortened medially.

Distribution and ecology: Pacific dominion (Sabana province), Boreal Brazilian dominion (Imerí and Napo provinces) and South American transition zone (Páramo province).Known from Amazon and Andean- Amazon piedemont of Colombia (Boyacá, Caquetá, Cundinamarca, Meta, Putumayo and Valle del Cauca departments), Ecuador (Orellana, Pastaza and Sucumbios provinces), and Peru (Loreto department) ( Fig. 24b View Figure 24 ). It is a rare species in entomological collections. Collected from 200 to 1,200 m of altitude. with pitfall traps baited with carrion and human and pig feces.

Taxonomic comments: Based on the external morphology, the shape of the ventral clypeal process and the endophallites, this species is included as Dichotomius (Dichotomius) . However, the inconspicuous meso-metaventral suture, exclusive to this species in Dichotomius (also seen in Canthidium ), and the subquadrangular, apically truncate parameresdo not allow D. compressicollis to be assigned to any species group and is, therefore, considered an incertae sedis species. It may later be elevated to a monospecific subgenus within Dichotomius , or described as an independent genus.