Dichotomius (Luederwaldtinia) amplicollis ( Harold, 1869 )

Montoya-Molina, Santiago & Vaz-De, Fernando Z., 2021, Taxonomic review of the Dichotomius (Luederwaldtinia) agenor species group (Coleoptera: Scarabaeidae: Scarabaeinae), European Journal of Taxonomy 734, pp. 1-64 : 12-15

Dichotomius (Luederwaldtinia) amplicollis ( Harold, 1869)

Fig. 4 , Map 2

Pinotus amplicollis Harold, 1869: 501 (original description).

Pinotus amplicollis – Blackwelder 1944: 69.

Dichotomius amplicollis – López-Guerrero 2005: 196.

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 (here designated) MEXICO • ♂; “ Oaxaca P. amplicollis .” [white with red margins, hw]/ “Mexico amplicollis Harold ” [white, hw]/ “LECTOTYPE ♂ Pinotus amplicollis Harold des. F.Z. Vaz-de-Mello, 2014” [red with black margin, phw]; MNHN.

Paralectotype

MEXICO • 1 ♀; “Sallé”. “ P. amplicollis mihi. ♀” [hw, Harold’s handwriting]/ “PARALEC- TOTYPE ♀ Pinotus amplicollis Harold des. F.Z. Vaz-de-Mello, 2014” [yellow with black margin, phw]; MNHN .

Additional material

MEXICO – Chihuahua • 1 ♂, 1 ♀; Pinos Altos; Buchan-Hepburn. B.C.A; p.52. sp.2; BMNH . – Guerrero • 7 ♂♂, 1 ♀; Acahuizotlá ; 7.93; S. Pokorny leg.; BMNH • 1 ♀; Cuernavaca ; 24 Jun. 1987; CEMT . – Jalisco • 2 ♂♂; Casimiro Castillo, Ej Barranca de la Naranjera , Cam. al Parotal ; 550 m a.s.l.; 19º35′10″ N, 104º24′43″ W; 29 Jul. 2004; Nicolalde, Carrillo and Vaz-de-Mello leg.; CEMT • 2 ♂♂; San Cristobal de la Barranca, Rancho El Tablón ; 850 m a.s.l.; 21º03′36″ N, 103º25′50″ W; 24 Jul. 2004; Nicolalde, Carrillo and Vaz-de-Mello leg.; CEMT • 2 ♂♂, 1 ♀; Chamela , E.B. Selva baja ; calamar; Jul. 2002; Ellen Andersen leg.; CEMT • 1 ♂, 1 ♀; Unión de Tula, Km 131 Carr. Guadalajara-Barra de Navidad; 1110 m a.s.l.; 19º52′46″ N, 104º18′58″ W; 30 Jul. 2004; Nicolalde, Carrillo and Vaz-de- Mello leg.; CEMT • 1 ♀; Tonaya, Las Higueras, Jardín de Casa ; 950 m a.s.l.; T. luz mercurial; Aug. 2004. R. Carrillo leg.; CEMT • 1 ♀; Cocula, RMO El Mirador ; 1970 m a.s.l.; 20º18′15″ N, 103º53′04″ W; 30 Jul. 2004; Nicolalde, Carrillo and Vaz-de-Mello leg.; CEMT • 2 ♀♀; Zapopan , Los Guayabos , BE.pert; 1600 m a.s.l.; exNTP-80 pulpo; 11 Jun.–8 Jul. 1994; G.A. Quiroz and J.L. Navarrete leg.; CEMT • 1 ♀; Ventanas, Mex ; 200 ft a.s.l.; Forter. B.C.A. p.52. sp.2; MNHN . – Mexico • 1 ♂; Temascaltepec ; Hinton Coll. B.M; BMNH 1939-583 • 4 ♂♂, 8 ♀♀; Real de Arriba , Temascaltepec; 1933; Hinton Coll. B.M; BMNH 1939-583 • 2 ♂♂, 1 ♀; Bejucos , Temascaltepec; 1933; Hinton Coll. B.M; BMNH 1939-583 • 1 ♀; Tejupilco, Temascaltepec ; 1933; Hinton Coll. B.M; BMNH 1939-583 . – Sonora • 1 ♂, 1 ♀; La Estrella; 10-32; Hinton Coll. B.M; BMNH 1939-583 • 2 ♀♀; Alamos ; Buchan-Hepburn, B.C.A; p.52. sp.2; BMNH . – Oaxaca • 1 ♂, 1 ♀; Panixtlahuca; BMNH • 4 ♀♀; Oaxaca ; Hoege. B.C.A; p.52. sp.2; BMNH .

Redescription

Male

MEASUREMENTS. Length: 21.7 mm.

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 fine 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.

ELYTRA. Interstriae shagreened with fine randomly separated punctures. Striae strongly marked, crenulate, ocellate punctures separated by diameter of a puncture on elytral disc (see Fig. 2I ).

LEGS. Posterior metacoxa edge bearing row of organized, shallow ocellate setigerous punctures which merge together ( Fig. 4H ).

PARAMERES AND LAMELLA COPULATRIX. As in Fig. 4 E–G.

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 Pacific 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.

Figures

Fig. 4. Dichotomius amplicollis (Harold, 1869). A–B. Dorsal habitus. A. ♂. B. ♀. C. Lateral view of the aedeagus. D. Anterior view of the cephalic carina, the central tubercle cylindrical and apically emarginate.E. Ventral view of the aedeagus. F–G. Lamella copulatrix. H. Ventral view of the metacoxa, displaying a single row of organized ocellate setigerous punctures which merge together on the posterior margin.

Fig. 2. General characters that help differentiate the species of the Dichotomius (Luederwaldtinia) agenor species group. A–D. Ventral clypeal process. A. Cordate as in D. agenor (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.