Coelotrachelus symbius ( Gordon and Howden, 1973 )

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 : 8-11

Coelotrachelus symbius ( Gordon and Howden, 1973)

( Fig. 23-27 )

Aphodius symbius Gordon and Howden, 1973: 438 .

Aphodius (Coelotrachelus) symbius ; Dellacasa 1988: 237.

Coelotrachelus symbius ; Skelley et al. 2007: 3 (new combination).

Type locality. Navajos, 20 miles E EI Salto, Durango, Mexico.

Type repository. Canadian National Collection. Ottawa (paratype male examined).

Redescription. Length 6.0-7.0 mm, oval-elongate, moderately convex, shiny, glabrous. Dark reddish to light brown; legs brown reddish; antennal club testaceous. Head with epistome feebly gibbous on disc, abruptly bent downward anteriorly, very finely and regularly punctured, punctation distally near obsolete; clypeus broadly sinuate at middle, with a small feebly upturned tooth at each side, not bordered, elongately ciliate; genae 90 o, elongately ciliate, protruding more strongly than eyes; frontal suture short, impressed laterally only; front relatively more distinctly and densely punctured. Pronotum transverse, moderately convex, widely explanate on sides, dually punctured; large punctures, eight to nine times larger than small, irregularly sparse, lacking on disc and on anterior third, almost contiguous near posterior angles; small punctures nearly imperceptible and regularly scattered throughout; anterior angles rounded; lateral margins feebly arcuate, thickly bordered; hind angles abruptly truncate and inwardly sinuate, ending with a distinct angulation at level of sixth elytral stria; base feebly bisinuate, not bordered at all. Scutellum feebly convex, smooth. Elytra almost convex, feebly widened backward, with a very small humeral tooth; striae very fine, superficially punctured, faintly crenulate; intervals flat, almost imperceptibly punctured. Hind tibial upper spur nearly as long as first tarsal segment; latter as long as following three segments combined. Male fore tibial apical spur rather stout, inwardly feebly curved at apex, abruptly bent downward; aedeagus Fig. 24-25 . Female fore tibial spur slender, elongate, slightly sinuate, regularly acuminate.

Material examined. MEXICO, Durango: Durango , 6200’, 14.VIII.1947, leg. Cazier, D. Rockefeller Exp. (3 exx., AMNH) ; 20 mi E El Salto , 6000’, 17-19.VI.1972, leg. H. F. Howden, in gopher burrow (1 ex., paratype, DCGC) ; 5 mi W Durango , 23.VI.1964, leg. H. F. Howden (1 ex., paratype, DCGC) ; Sinaloa: 38 mi NE Concordia, nr. Loberas [= La Lobera], 03.VIII.1982, black light (1 ex. DCGC) .

Distribution. Mexico (Durango, Sinaloa).

Bionomics. Specimens were taken in a jar baited with human feces placed in the floor of a gopher burrow; others were dug from the main burrow system where there was indication of fresh gopher activity.

Figures

Figures 23-27. Coelotrachelus symbius (Gordon and Howden, 1973). 23) Habitus (morphological details). 24-25) Aedeagus (dorsal and lateral view). 26) Habitus. 27) Epipharynx.