Stenotothorax Schmidt 1913
Stenotothorax Schmidt 1913: 122

Stenotothorax badipes (Melsheimer)	Stenotothorax parapyriformis Gordon and Skelley
Photos by P. Skelley.

Type species. Aphodius oblongus Say 1823: 215 [ valid name Aphodius badipes Melsheimer 1844], by subsequent designation.
                  = Stenothorax Schmidt 1914: 204 (mispelling)
                  = Stenobronchus Schmidt 1916: 98 (unnecessary replacement
                  name). Type species: Aphodius oblongus Say 1823: 215

Diagnosis. Body length 4.3-11.2 mm, elongate, parallel-sided or not, somewhat flattened, reddish-brown to black. Head with frontal suture obsolete, surface smooth, coarsely punctate or rugose. Clypeus variably toothed or rounded each side of median emargination. Pronotum narrower at base than apex; posterior angles obsolete, truncated or rounded; basal marginal line usually present. Elytra widest posterior of middle; humerus rounded to dentate. Many brachypterous with metasternum short. Metatibial apical spinules short, equal in length.

Distribution. Eastern Palearctic, North America into Mexico.

Composition. Worldwide, Stenotothorax contains 24 species, 23 of which occur in the New World.

Stenotothorax badipes (Melsheimer 1844: 135) [Aphodius], E-US.
                  = Aphodius oblongus Say 1823: 215 [not Aphodius oblongus (Scopoli 1783 )
                  [Scarabaeus]].
                  = Aphodius badiceps Fall in Gordon 1983: 636 (lapsus).
Stenotothorax cadaverinus (Mannerheim 1843: 261) [Oxyomus], CA-USA.
Stenotothorax comosus Gordon and Skelley 2007: 200, NV-USA.
Stenotothorax cribratulus (Schmidt 1922: 42) [Aphodius], NW-USA.
                  = Aphodius cribratus LeConte 1878: 455 [not Aphodius cribratus Mulsant
                  1842].
Stenotothorax dilaticollis (Saylor 1935: 80) [Aphodius], NW-USA.
Stenotothorax gardneri (Gordon 2006: 49-51) [Aphodius], MO, OK, TX-USA.
Stenotothorax gentilis (Horn 1887: 24) [Aphodius], W-USA.
Stenotothorax gravis (Fall 1927: 137) [Aphodius], CA-USA.
Stenotothorax lanei (Saylor 1940: 103) [Aphodius], NW-USA.
                  = Aphodius caseyi Saylor 1940: 104.
                  = Aphodius pullmani Saylor 1940: 104.
Stenotothorax linsleyi (VanDyke 1933: 115) [Aphodius], CA-USA.
Stenotothorax martini (VanDyke 1928: 153) [Aphodius], W-USA.
Stenotothorax mcpeaki Gordon and Skelley 2007: 207, NW-USA.
Stenotothorax micellus Gordon and Skelley 2007: 208, NW-USA.
Stenotothorax nevadensis (Horn 1887: 23) [Aphodius], W-USA.
Stenotothorax oriens Gordon and Skelley 2007: 210, NW-USA.
Stenotothorax oviformis (Robinson 1946: 53) [Aphodius], CA-USA.
                  = Aphodius inyoensis VanDyke 1947: 158.
Stenotothorax ovipennis (Horn 1870: 133) [Aphodius], CA-USA.
Stenotothorax parapyriformis Gordon and Skelley 2007: 212, W-USA.
Stenotothorax pyriformis (Brown 1929: 205) [Aphodius], W-USA.
Stenotothorax rugoclypeus (Hinton 1934: 219) [Aphodius], CA-USA.
Stenotothorax sparsus (LeConte 1878: 458) [Aphodius], SW-USA, Mexico.
                  = Aphodius blaisdelli Fall 1905: 129.
                  = Aphodius sparsus sheldoni Barrett 1932: 172.
Stenotothorax washtucna (Robinson 1938: 108) [Aphodius], NW-USA.
                  = Aphodius washtuca in Saylor 1940: 1-3 (misspelling).
                  = Aphodius constrictus Robinson 1946: 54.
Stenotothorax woodleyi Gordon 2006: 47-48, WA-USA.

Life History. Solid host data is lacking for many species. Some species are associated with small mammals; pack rats, pocket gophers, and tree squirrels. Other species may be general detritivores, detritivores in rodent nests, or rodent dung generalists in specific habitats.

Larvae. The larva of S. sparsus is described in Ritcher (1966).

Status of Classification. Two species groups are recognized in Stenotothorax (Gordon and Skelley 2007) based on external morphology and wing development. The flightless species group is highly variable in character states presently used to define other genera. A simple diagnosis of Stenotothorax is nearly impossible.

References:
Gordon, R. D., and P. E. Skelley. 2007. A monograph of the Aphodiini inhabiting the United States and Canada (Coleoptera: Scarabaeidae: Aphodiinae). Memoirs of the American Entomological Institute 79: 580 pp.
Ritcher, P.O. 1966. White grubs and their allies: A study of North American scarabaeoid larvae. Oregon State University Press, Corvallis, Oregon. Studies in Entomology 4: 219 pp.