Deltochilum (Aganhyboma) valgum Burmeister 1873
Creators: name: Silva, Fernando A. B.
name: Louzada, Júlio
name: Vaz-De-Mello, Fernando
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Deltochilum
Deltochilum valgum

description: Deltochilum (Aganhyboma) valgum Burmeister 1873 new subgeneric placement
(Figs 17, 30, 38, 47, 55, 75, 88, 93, 118)
Deltochilum valgum Burmeister 1873: 409 (original description)
Gillet 1911: 36 (catalogue)
Bruch 1911: 186 (catalogue)
Blackwelder 1944: 185 (checklist)
Larsen et al. 2009: 1–4 (feeding behavior, "misidentification" probably refers to the species described here as D. larseni)
Deltochilum (Deltochilum) var. valgum: Paulian 1938: 252, 269, 271, 276, map n. 5 (description, taxonomic comments and identification key)
Deltochilum (Deltohyboma) valgum: Martínez 1959: 55 (catalogue)
Vulcano & Pereira 1964: 659 (catalogue)
Martínez 1987: 55 (checklist)
Deltochilum valgum valgum: Cano 1998: 177 (ecological comments)
Deltochilum (Deltohyboma) valgum valgum: Vaz-de-Mello 2000: 192 (checklist)
Description. Body. Head, pronotum, elytra and ventral surface black or dark brown, with an opaque or silky sheen. Length 14 to 15 mm. Head. Foveiform punctures dense, but not touching each other as in D. icaroides; around clypeus quite shallower and smaller than those on the dorsal interocular surface. Lateral margin of gena, around eyes, without row of setae or with almost inconspicuous setae. Interocular distance approximately four times eye width. Thorax. Surface of pronotum with deep and dense foveiform punctures, nearly touching on the sides and posterior angles. Discal punctures somewhat smaller and more dispersed than those of lateral portion. Anteromedial punctures smaller and more dispersed than discal punctures. Posteromedial punctures usually separated by at least one diameter. Margin between anterior and lateral angles with row of small setae. Margin between lateral and posterior angles straight. Hypomera with dense foveiform punctures on anterior and posterior portions; foveiform punctures almost touching. Elytra. Lateral margins slightly curved outward (Fig. 118), or almost parallel, and surface slightly irregular (rugose). Elytral striae wider, carinate margins clearly separated (Fig. 75). Interstriae slightly convex; however, always less convex than that of the icariforme subcomplex. Interstriae with foveiform punctures over entire surface (Fig. 75). Microtubercles of interstriae dense and conspicuous (Fig. 75). Basal carina of seventh interstria elongate, length about four times the width of the seventh interestria. Basal carina of ninth interstria present in three-quarters of elytra, but it never reaches the anterior limit of apical carina of seventh interstria. Apical carina of third interstria round, better defined as tubercle, distinctly more prominent than the apical carina of second and fourth interstriae (Fig. 88). Length of apical carina of sixth interstria longer than that of apical carina of fifth interstria. Length of apical carina of seventh interstria less than or equal to the sum of lengths of apical carinae of fifth and sixth interstriae. Pseudepipleural carina complete, visible entire length of epipleuron (as in Fig. 63).
Material studied. Holotype (MACN) [image examined]: 1. [white label, bordered and printed in black]. MACN-En/ 1525; 2. [red label, bordered in black, handwritten]. Deltochilum / valgum / Burmeister/ 1873 / Typus; 3. [white label, bordered in black, handwritten and printed]. Deltochilum / valgum valgum / Lectotipo Burm/ A.
Martínez Det. 1950; 4. [old white label, handwritten]. valgum / Burm./ Rep. Arg.; 5. [white label, bordered in red, handwritten]. 52977; 6. [old white label, printed in black]. Col./ Antigua; 7. [green label, printed in black]. Tucuman.
The locality data in original description was given as “near Tucumán”. Fabio Arturo González supplied high resolution images of a specimen from Tucumán, deposited at the MACN, with a lectotype label placed by Antonio Martínez. However, Martínez did not publish this designation. After studying the original description of Burmeister, we belive that the author described this species from a single specimen. Therefore, the specimen with the lectotype designation by Martínez is the holotype.
Non-type material [10]: ARGENTINA: CORDOBA: El Sauce, Diquecito, Martínez (1 ♀ CEMT); same, XII.1964, Martínez (1 ♂ CMN); FORMOSA: San José, 20.XI.1948, E. Budim (1 ♂ CEMT); JUJUY: Km 38/Ruta 52, 17.I.2008, K.S. Ramos (1 ♂ CEMT); P. N. Calilegua (3 km NW de campground), (23°44.149'S, 064°51.044'W), 15.I.2008, D.M. Takiya (1 ♀ CEMT); P. N. Calilegua (Estaca el Cero), 28.XII.1987, S. & J. Peck (1 ♀ CMN). BOLIVIA: SANTA CRUZ: Caballero, ~9Km Sudoeste Comarapa, (17°57.847'S, 64°27.745'W), XII.2008, W.D.E. Edmonds & T. Vidaurre (1 ♂ WDEC); Chiquito, Santiago de Chiquito, (18º19'S, 59º34'W), 11.XI.2008, T. Vidaurre (1 ♂ 1 ♀ CEMT). PARAGUAY: PRESIDENTE HAYES: Pozo Colorado, Trans-Chaco [highway], IV.1995, J.C. D'Alessandro (1 ♂ CEMT).
Sampling methods. at light-trap [3 specimens]; baited pitfall trap with injured diplopods [2].
Habitat. Argentina, Bolivia and Paraguay (Fig. 93). From available data this species inhabits mainly the Chaco domain. Two specimens with label data "Chiquitano" [a transition zone between the moist Amazonian forests of the north and dryer forest of the southern Chaco regions].
Diagnosis and remarks (within the valgum complex): length 14 to 15 mm; elytral interstriae with homogeneous and dense foveiform punctures over entire surface; elytral surface with an opaque or silky sheen; apical carina of third interstria distinctly more prominent and rounded than apical carinae of second and fourth interstriae (Fig. 88). The following aedeagus characters are also diagnostic: parameres symmetric and short; in lateral view forming an angle of approximately 30° with phallobase; apex rounded (Fig. 17). Genital segment as in Fig. 30. Lamella copulatrix (LC): left lobe subrectangular (Fig. 38); right lobe "b"-shaped (Fig. 38). Superior right peripheral sclerite (SRP) as in Fig. 47. Fronto-lateral peripheral sclerite (FLP) as in Fig. 55.
The specimens present the foveiform punctures of head and pronotum more sparse than that in D. icaroides.
description: Published as part of Silva, Fernando A. B., Louzada, Júlio & Vaz-De-Mello, Fernando, 2015, A revision of the Deltochilum subgenus Aganhyboma Kolbe, 1893 (Coleoptera: Scarabaeidae: Scarabaeinae), pp. 451-504 in Zootaxa 3925 (4) on pages 483-484, DOI: 10.11646/zootaxa.3925.4.1, http://zenodo.org/record/244795