Coelotrachelus rudis ( LeConte, 1878 )

Dellacasa, Marco, Dellacasa, Giovanni & Gordon, Robert D., 2009, Systematic revision of the genus Coelotrachelus Schmidt, 1913 (Scarabaeoidea: Scarabaeidae: Aphodiinae), Insecta Mundi 2009 (86), pp. 1-13 : 6-8

Coelotrachelus rudis ( LeConte, 1878)

( Fig. 18-22 )

Aphodius rudis LeConte, 1878: 458 .

Aphodius (Platyderus) rudis ; Schmidt, 1913: 123.

Aphodius (Platyderides) rudis ; Schmidt 1922: 49; Dellacasa 1988: 191.

Aphodius feneyesi Van Dyke, 1947: 159 ; Gordon and Skelley 2007: 481 (as synonym of C. rudis ); Skelley et al. 2007: 3.

Coelotrachelus rudis: Gordon and Skelley 2007: 481 (new combination); Skelley et al. 2007: 3.

Type locality. Colorado [ U.S.A.].

Type repository. Museum of Comparative Zoology (Cambridge, MA, USA) (type not examined)

Redescription. Length 6.0- 7.5 mm, elongate, moderately convex, shiny, glabrous. Chestnut-brown, pronotal disc somewhat darker; antennal club pale testaceous. Head with epistome slightly convex on disc, very finely subregularly punctured throughout; clypeus broadly and feebly sinuate at middle, denticulate at sides (small denticles not upturned), faintly bordered, border laterally rather elongately sparsely ciliate; genae subacute, sparsely elongately ciliate, protruding more strongly than eyes; frontal suture short only laterally impressed; front relatively more distinctly punctured. Pronotum broadly transverse, feebly convex, dually punctured, large punctures, seven to eight times larger than small, rather densely arranged laterally, small punctures extremely fine and regularly sparse throughout; sides widely explanate, thickly bordered, border glabrous, S-shaped and distinctly crenulate before subacute hind angles placed at level of fifth elytral stria; base slightly bisinuate, not bordered. Scutellum with few fine basal punctures. Elytra oval, moderately convex, subdenticulate at shoulder; striae fine, superficially punctured, not crenulate at all; intervals nearly flat, minutely sparsely punctate. Hind tibial upper spur as long as first tarsal segment; latter as long as following three segments combined. Male fore tibial spur relatively short, blunt apically, abruptly bent downward; larger punctures of pronotum less widely spread; aedeagus Fig. 19-20 . Female fore tibial spur relatively slender and regularly acuminate toward apex, not so abruptly bent downward; larger punctures of pronotum relatively more widely spread.

Material examined. MEXICO, Chihuahua: Canon Prieto, nr. Primavera , 6500-6800’, 02.VII.1947, leg. Cazier, D. Rockefeller Exp. (3 exx., AMNH) ; Catarinas , 5800’, 25.VI.1947, leg. Michener, D. Rockefeller Exp. (3 exx., AMNH) ; 44 mi S Hidalgo de Parral , 10.VII.1954, leg. J. W. Mac Swain (1 ex., DCGC) ; 8 mi W Matachic , 6400’, 08.VII.1947, leg. Spieth, D. Rockefeller Exp. (2 exx., AMNH) ; Santa Barbara , 6300’, 18.VII.1947, leg. Spieth, D. Rockefeller Exp. (2 exx., USNM) ; Yaguirachi , 8500’, 30 mi W Chihuahua, 22.VI.1957 (1 ex., USNM) ; USA, Arizona: Madera Can. , Pima Co., 15.VII.1981, leg. C. Lenczy (3 exx., DCGC) ; Prescott , 16.VIII.1951, leg. G. H. Nelson (1 ex., DCGC) ; Rio Rico , Sta. Cruz Co., VII.1982, leg. C. Lenczy (3 exx., DCGC) ; Williams , 09.VIII.1938, leg. D. J. & J. N. Knull (1 ex., DCGC) .

Distribution. U.S.A. (southern Colorado, south in the mountain ranges of southern Arizona (Flagstaff) and northern and western New Mexico (Luna)), Mexico (Chihuahua).

Bionomics. Most specimens examined were collected between April and September; a rodent burrow associate, collected from burrows of the prairie dog Cynomys gunnisoni zuniensis Hollister (Gordon personal observation). It has been collected and reared from burrows of pocket gophers, Thomomys spp. ( Gordon and Skelley 2007). Other genera of rodents may also serve as hosts. Coelotrachelus rudis is attracted to light.

Figures

Figures 18-22. Coelotrachelus rudis (LeConte, 1878). 18) Habitus (morphological details). 19-20) Aedeagus (dorsal and lateral view). 21) Habitus. 22) Epipharynx.