Dichotomius (Luederwaldtinia) fornicatus ( Luederwaldt, 1931 )

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 : 27-29

Dichotomius (Luederwaldtinia) fornicatus ( Luederwaldt, 1931) Fig. 9 , Map 6

Pinotus opacipennis var. fornicatus Luederwaldt, 1931: 302 (original description).

Dichotomius bosqi Pereira, 1941: 263 (original description). Syn. nov.

Dichotomius opacipennis var. fornicatus – Blackwelder 1944: 207.

Dichotomius bosqi Martínez 1959: 89 .

Diagnosis

Dichotomius fornicatus is separated from other species in the group by the following combination of characters: small body size, less than 15 mm. Dorsal and ventral surface dark blue to black. Head cephalic carina, distinctly arcuate in dorsal view, middle edge slightly forward of lateral. Pronotum with abrupt anterior declivity when viewed laterally, middle surface deeper, apex of the declivity with two well-developed lobes. Elytra opaque, shagreened microsculpture.

Material examined

Holotype of P. fornicatus ARGENTINA • ♀; “Republ. Argentine CHACO DEL ESTERO, RIO SALADO” [white with black superior and inferior margins, p]/ “DÉCEMBRE” [white, p]/ “MÚSEUM PARIS 1938 COLL. A. BOUCOMONT” [green with black margins, p]/ “ Pinotus opacipennis Lueder. Forma a. Luederw. Det. 1931” [white, hw]; MNHN.

Holotype of D. bosqi

ARGENTINA • ♂; “ Sgo del ESTERO . Rio Salado. WAGNER col.” [white with black margins, p]/ “TIPO” [red with black margins, p]/ “ Pinotus bosqi P. Pereira det. 940” [white with black margins, phw]/ “23.030” [white, hw]; MZSP.

Paratype

ARGENTINA • 1 ♀; “ Sgo del ESTERO . Rio Salado. WAGNER col.” [white with black margins, p]/ “ ♀” [white, hw]/ “Paratypo” [red, hw]/ “ Pinotus bosqi ♀ P. Pereira det. 941” [white with black margins, phw] /“289” [red rounded, hw]; MLP .

Additional material

ARGENTINA – Cordoba • 1 ♀; La Para. C/esc; Dec. 1996; Monteresino leg.; CEMT • 1 ♂; C. a mano ; Nov. 1990; Monteresino; CEMT • 4 ♀♀; Salta, Salado River ; J.V. González and S. Macapilo leg.; 18 Jan. 2010; Snizek leg.; CEMT • 1 ♂; Rosa. Front. El Naranjo ; A. Martínez leg.; MACN • 1 ♂; Tablillas ; Dec. 1932 – Sep. 1933; CEMT. – Santiago del Estero • 2 ♀♀; Campo Gallo, S. del. Estero ; Mar. 1943; A.F.P. B.M; BMNH 1948-159 • 2 ♂♂, 1 ♀; Choya ; Oct. 1961; MLP • 1 ♂, 4 ♀♀; El Charco ; Feb. 1956; MLP • 1 ♂; Matará ; 12 Dec. 1939; Biraben-Bezzi leg.; MLP • 2 ♂♂; Rio Salado ; Wagner leg.; MLP • 2 ♀♀; Thermas de Rio Hondo ; 27–28 Nov. 1979; C. and M. Vardy B.M. leg.; BMNH 1980-67 • 1 ♀; Tucumán; Jan. 1947; CEMT • 1 ♀; Dec. 1948; CEMT • 1 ♀; Campo Bello ; Mar. 1943; MACN • 1 ♂, 1 ♀; San Pedro Colalao ; Feb. 1949; CEMT • 1 Ƌ; “ METATIPO”/ “Campo Gallo, S. del Estero III-1943 A.F.P.”/ “ Pinotus Ƌ bosqi P. Pereira det. 948/B.M. 1948-159.” / “NHMUK 010847032”; BMNH • 1 ♀; “ METATIPO” /“Campo Gallo, S. del Estero III-1943, A.F.P.” /“ Pinotus ♀ bosqi P. Pereira det. 948 /B.M. 1948-159” / “NHMUK 010847033”; BMNH .

BOLIVIA • 1 ♀; Cordillera, Tunalito ; 8 Nov. 1946; Maldonado leg. and coll. Martinez.; CEMT. – Santa Cruz • 1 ♂, 1 ♀; Ascención ; Nov. 1963; MLP • 1 ♀; Ñuflo de Cháves ; Nov. 1963; MLP • 1 ♂; Yoay ; Dec. 1933; G.L. Harlington leg.; CEMT • 1 ♂; Tarija, Res.Priv. Corbalán ; 298 m a.s.l.; 21º39′ S 62º28′ W; chaco seco. trap. caída cebo humano; 12 Dec. 2004; C. Hamel and M. Aliaga leg.; CEMT • 2 ♂♂, 2 ♀♀; between Caiza and Creveaux; 536 m a.s.l.; 21º48′53″ S, 63º26′53″ W; blue light; OUMNH-2005-065 ; 05-I-2005; Mann, Hamel and Herzog leg.; CEMT • 1 ♂; Yoay and Mandipecua [Yoay y Mandeyapecua]; collector 479; Nov. 1932; Press by WCH rington; CEMT .

PARAGUAY – Boquerón • 2 ♂♂, 3 ♀♀; Loma Plata , Chaco ; 8–29 Jan. 1995; CEMT . – Caaguazú • 1 ♀; Capiata ; 20 Nov. 2001; C. Aguilar leg.; CEMT .

COUNTRY UNKNOWN • 1 ♂; no data; CEMT • 1 ♂, 1 ♀; B.M.; BMNH 1948-159 .

Redescription

Male

MEASUREMENTS. Length: 13.35 mm. Dorsal and ventral surfaces dark blue to black. Pronotum and ventral surfaces shiny, elytra opaque.

HEAD. Surface rugosity not extending posteriorly to base of cephalic carina; interocular surface with well-impressed punctures near eyes. Cephalic carina, wider than high, distinctly arcuate in dorsal view ( Fig. 9G ), middle edge slightly forward of lateral. Median tubercle approximately twice as high as lateral tubercles, conic in shape and slightly curved posteriorly. Ventral clypeal process cylindrical (see Fig. 2D ).

PRONOTUM. Wider than long. Antero-median declivity of pronotal disc with two underdeveloped lobes at sides when viewed laterally ( Fig. 9A ). Pronotal disc shiny with dense deep punctures, separated by diameter of a puncture; margins rugose, denser at antero-lateral edges. Hypomeron medial disc smooth and shiny, external margin with single row of organized and scattered setae of same length.

ABDOMEN. Mesosternum covered by large ocellate punctures separated by diameter of a puncture. Metasternum antero-medial edge smooth and shiny. Ocellate punctures restricted mainly to lateral edges, punctures separated by width of a puncture. Small ocellate punctures surrounding margin of mesocoxa ( Fig. 9D ). Ocellate punctures along the anterior margin of sternites; sixth abdominal sternite lower or depressed than others. Pygidium medial disc finely punctate, delimited by margin that widens towards apical part; basal inner margin rugose.

ELYTRA. Opaque. Interstriae microsculpture shagreened; fine shiny punctures disposed randomly. Striae black, weakly impressed, punctures separated by twice diameter of a puncture on elytral disc.

LEGS. Metacoxa posterior edge bearing row of small impressions, not punctures, separated by twice diameter of the impression. Setigerous punctures next to trochanter insertion larger, twice the size of small ones.

PARAMERES AND LAMELLA COPULATRIX. As in Fig. 9C , E–F.

Morphological variation

Females ( Fig. 9B ) are distinguished from the males as follows:

HEAD. Surface completely rugose, denser towards anterior portion. Cephalic carina trituberculate, median tubercle higher than lateral tubercles, surface punctate. Lateral tubercles narrow.

PRONOTUM. Weak medial depression, surface punctures greatly impressed separated by length of diameter of a puncture. Medial sulcus conspicuous.

Remarks

This species was first described by Luederwaldt (1931) based on a female as a variety of D. opacipennis , placing it in the inachus section as part of the lucasi group. The holotype locality was Santiago del Estero, Rio Salado, the same later used by Pereira (1941) to described D. bosqi . The description of the male of this species was by Pereira (1941). Based on the abovementioned taxonomic characters and the possibility of comparing specimens to the holotype, we suggest these species to be synonyms. Within the species group, D. fornicatus and D. rafanunezi sp. nov. are the only species where the cephalic carinae of females are trituberculate.

Figures

Fig. 9. Dichotomius fornicatus (Luederwaldt, 1931). A–B. Dorsal habitus. A. ♂. B. ♀. C. Lateral view of the aedeagus. D. Ventral view of the metasternum. Antero-medial edge smooth and shiny, surface near the interior margin of the mesocoxae punctate. E. Ventral view of the aedeagus. F–G. Lamella copulatrix. H. View from above of the head, cephalic carina arcuate.

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.