Onthophagus fuscus, Boucomont, 1932

Joaqui, Tatiana, Moctezuma, Victor, Sánchez-Huerta, José Luis & Escobar, Federico, 2019, The Onthophagus fuscus (Coleoptera: Scarabaeidae) species complex: an update and the description of a new species, Zootaxa 4555 (2), pp. 151-186 : 177

Key for the identification of adult major male specimens of the Onthophagus fuscus species complex

(modified from Zunino & Halffter 1988).

1 Clypeus not transverse, obtusely pentagonal and not concave or weakly concave ( Figs. 1, 3, 5, 7, 9, 13)................. 2

- Clypeus transverse, obtusely trapezoidal and strongly concave ( Fig. 11).......................................... 7

2 Frontal carina complete................................................................................. 3

- Frontal carina limited to the medial region.................................................................. 5

3 Dorsal setae (pronotum and elytra) relatively long (length: 0.1 ± 0.03 mm). Pronotal disc glabrous medially ( Figs. 3–4, 18 – 20). Michoacán, Mexico...................................................... O. canescens Zunino & Halffter, 1988

- Pronotal setae relatively short (length: 0.07 ± 0.02 mm). Pubescence present on the entire pronotal disc................. 4

4 Protonal surface coppery without olive-green sheen and elliptical impressions. Clypeal carina lacking ( Figs. 9–10, 18 – 20). Hidalgo, Puebla, and Veracruz, Mexico...................................... O. parafuscus Zunino & Halffter, 2005

- Protonal surface coppery with an olive-green sheen, with two more-or-less elliptical impressions on each of midline. Clypeal carina weakly impressed ( Figs. 13 – 16). Veracruz, Mexico.................................................................................................... O. orizabensis Moctezuma, Joaqui , & Sánchez-Huerta, new species

5 Frontal carina produced into an acute or flattened triangular tubercle between the genal sutures. Elytral striae fine ( Figs. 7–8, 18 – 20). Durango, Jalisco, and Sinaloa, Mexico.............................. O. pseudofuscus Zunino & Halffter, 1988

- Frontal carina not produced into an acute tubercle. Elytral striae strongly impressed................................. 6

6 Clypeal carina present, but weakly developed. Dorsal surface dark brown with a weak greenish-cupreous sheen ( Figs. 1, 2, 18 – 20). Aguascalientes, Durango, Jalisco, and Zacatecas, Mexico............................. O. fuscus Boucomont, 1932

- Clypeal carina absent. Dorsal surface coppery with a strong metallic sheen ( Fig. 5–6, 18 – 20). Morelos, Mexico................................................................................. O. mycetorum Zunino & Halffter, 1988

7 Pubescence uniform in size and density on the pronotal disc ( Fig. 11–12). Puebla, Mexico......................................................................................... O. clavijeroi Moctezuma, Rossini, & Zunino, 2016

- Pubescence reduced in size and density on the postero-central region of the pronotal disc. See dorsal habitus at http:// unibio.unam.mx/irekani/bitstream/123456789/12809/1/9035.jpg. Morelos, Mexico.................................................................................................... O. navarretorum Delgado & Capistan, 1996