Dichotomius (Luederwaldtinia) sagittarius Montoya-Molina & Vaz-De 2021, stat. rev.
Creators: name: Montoya-Molina, Santiago
name: Vaz-De, Fernando Z.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Dichotomius
Dichotomius sagittarius

description: Dichotomius (Luederwaldtinia) sagittarius (Harold, 1869) stat. rev. Fig. 13, Map 9
Pinotus sagittarius Harold, 1869 (original description).
Pinotus sagittarius – Luederwaldt 1929: 99. — Blackwelder 1944: 208.
Dichotomius amplicollis – López-Guerrero 2005: 196.
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 (here designated) MEXICO • ♂; “Toxpam P. sagittarius Harold. ” [white with red margins, hw]/ “ Ex-Musaeo E. Harold ” [white with black margins, p]; MNHN.
Paralectotypes (2 ♂♂, 1 ♀)
MEXICO • ♀; “Mexique Pinotus sagittarius Chevrol. ” [white, hw]/ “Ex-Museaeo E. Harold / PARALECTOTYPE ♀ Pinotus sagittarius Harold des. F.Z. Vaz-de-Mello, 2014” [yellow with black margin, phw]; MNHN • ♂;“Type” [white,rounded with red margins]/“Cordova”[white,p] / “Mexico Sallé Coll.” [white, p]/ “B.C.A. p. 52 sp.4” [white, phw]/ “ Pinotus sagittarius Type Harold apud Sallé” [white, hw]/ “NHMUK 010847040 [white, p]; BMNH • ♂; “Type” [white, rounded with red margins]/ “Cordova” [white, p]/ “Mexico Sallé Coll.” [white, p] / B.C.A. p. 52 sp.4 [white, phw]/ 720 [green, p]/ Pinotus sagittarius Type Harold apud Sallé [white, hw]/ P. Sagittarius Harold. [white, hw] /TYPE SAGITTARIUS HAROLD det. F. Génier, 2008 [white with black margins, phw] / PARALECTOTYPE [yellow with black margins, p]/ “NHMUK 010847041” [white, p]; BMNH.
Additional material
BELIZE • 1 ♂; Cayo, Las Cuevas Research station; 550 m a.s.l.; 16º43.99 N, 88º59.20 W; 22 May 2000; M. Caterino; BMNH • 4 ♂♂, 3 ♀♀; Chiquibul Forest Res, Las Cuevas field station; 500–700 m a.s.l.; 88º59′ W; 16º44′ N; May–Jun. 1997; D. Inward leg.; BMNH 2005-78.
MEXICO • 1 ♂; Fry leg.; BMNH 1905-100 • 1 ♀; Fry leg.; BMNH 1905-100 • 1 ♀; Curtis leg.; BMNH. – Chiapas • 12 ♂♂, 17 ♀♀; Marqués de Comillas, Chajul; 16º05′32″ N, 90º12′13″ W; Frag. Rafa; Aug. 2005; G. Ponce leg.; CEMT. – Oaxaca • 2 ♂♂; Santa María Chimalapa; 187 m a.s.l.; 16º55′27.2″ N, 94º42′20″ W; 12 Jul. 2015; Victor Moctezuma leg.; CEMT. – Veracruz • 6 ♂♂, 7 ♀♀; La Bocana; human faeces; 26 Jul. 1996; CEMT • 1 ♀; Fortín; 1–4 Oct. 1967; E. Greenwood leg.; CEMT. – San Luis • 1 ♂; 3 mi. W of El Naranjo; 1100 m a.s.l.; 10–18 Jun. 1971; A. Newton leg.; CEMT.
Redescription
Male
MEASUREMENTS. Length: 20.43 mm.
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 fine punctures. Row of interrupted ocellate punctures along Pronotal margins, denser on anterior and posterior margins (Fig. 13A). Pronotal medial disc shiny, covered by fine 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.
ELYTRA. Interstriae shagreened with fine, randomly separated punctures. Striae clearly marked, with ocellate punctures separated by diameter of a puncture on elytral disc (Fig. 13A).
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. 13 E–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.
description: Published as part of Montoya-Molina, Santiago & Vaz-De, Fernando Z., 2021, Taxonomic review of the Dichotomius (Luederwaldtinia) agenor species group (Coleoptera: Scarabaeidae: Scarabaeinae), pp. 1-64 in European Journal of Taxonomy 734 on pages 39-40, DOI: 10.5852/ejt.2021.734.1233, http://zenodo.org/record/4542107