Coelotrachelus macgregori ( Islas, 1955 ) Dellacasa & Dellacasa & Skelley & Gordon, 2017

Dellacasa, Marco, Dellacasa, Giovanni, Skelley, Paul E. & Gordon, Robert D., 2017, Systematic revision of the species of Geomyphilus (Coleoptera: Scarabaeidae: Aphodiinae) of Mexico and neighboring countries with description of a new Mexican species, Insecta Mundi 2017 (590), pp. 1-19 : 2

Coelotrachelus macgregori ( Islas, 1955) , new combination

Aphodius macgregori Islas, 1955: 223 .

Aphodius (Coelotrachelus) macgregori ; Deloya 1991: 204; Deloya and McCarty 1992: 6

Geomyphilus (s.l.) macgregori ; Skelley et al. 2007: 4.

Skelley et al. (2007) listed A. macgregori Islas in Geomyphilus (sensu lato). Study of external morphological characters (e.g. the shape of lateral pronotal margins towards the hind angles and the epipharyngeal structure) allow us to confirm placement of the species in the genus Coelotrachelus Schmidt, 1913 , becoming the new combination Coelotrachelus macgregori ( Islas, 1955) . Thus, the third couplet of the key to species of Coelotrachelus in Dellacasa et al. (2009) has to be modified as follows:

3(2).

— Lateral margins of pronotum regularly arcuate. Chestnut-brown. Length 6.0–7.0 mm. U.S.A.

(Arizona, Colorado, New Mexico); Mexico (Chihuahua, Durango) ....... C. rudis (LeConte) Lateral margins of pronotum almost straight, slightly inwardly sinuate before hind angles .... 3 ′ 3′(3) .

—

Large pronotal punctures lacking on anterior third of disc. Strongly shiny, dark reddish-brown. Length 6.5–7.5 mm. Mexico (Durango, Sinaloa) ........ C. symbius (Gordon and Howden)

Large pronotal punctures densely and subregularly scattered throughout. Moderately shiny, strongly dark reddish-brown, pronotal sides paler. Length 4.0–6.0 mm. Mexico (Distrito Federal, México, Morelos) .................................................................. C. macgregori (Islas)