262 PROCEEDINGS OF THE NATIONAL MUSEUM vol.im 



Geotrupes stercorarius (Linnaeus) 



Scarabaeus stercorarius Linn4, 1758, p. 349. — Gorham, Walker, and Simpson, 1929, 

 p. 15. — Brown, 1940, p. 74. (For complete synonymy see Boucomont, 1912, 

 pp. 24, 25. Only references pertaining to North American specimens are 

 given here.) 



The following description is intended only to separate the intro- 

 duced stercorarius from North American species and is based entirely 

 on New Brunswick specimens furnished me by W. J. Brown, Canadian 

 Department of Agriculture, Division of Insect Identification. 



Length 20 to 26 mm., greatest width 11 mm. to 16 mm. 



Color of dorsum black with traces of bluish iridescence in striae and 

 along thoracic and elytral margins in some specimens. Ventrally 

 black with strong blue or pm'ple iridescence on thorax, abdomen, and 

 fem.ora. Basal segment of antenna dark brownish black; other 

 segments, including the club, dark reddish brown. The middle 

 lamella of the antennal club is very strongly emarginate on one side. 

 Eye canthus, clypeus, and vertex densely rather finely irregularly 

 punctured. The three tubercles of the head moderately developed, 

 indented line present at base of clypeus extending for a short distance 

 on the vertex at median line. Clypeus margined, sharply arcuate 

 anteriorlj^. A slight obtuse angle is formed between edge of clypeus 

 and margined eye canthus. Pronotum completely margined, only 

 moderately convex, with a few coarse rather vague punctures present 

 laterally. The median lateral circular indentations are present but 

 shallow. Posterior half of pronotal midline may be slightly indented, 

 but usually lacks coarse punctiu-es. Minute secondary punctures 

 lacking. ScuteUum triangular, sides slightly arcuate. Elytra with 

 well developed striae which are vaguely and shallowly punctate. The 

 sutiu-al stria extends completely around the scutellum to elytral base 

 (this also occurs in balyi and hornii), and the second stria does not 

 quite reach the base. Elytral margin is narrow, slightly wider 

 anteriorl}^. 



The anterior-external tooth of the foretibia of the male is slightly 

 smaller than that of the female. In the male there is a longitudinal 

 carina ending in a tubercle on the ventral flattened surface of the 

 foretibia extending a distance roughly equal to that between the 

 fourth to sixth external teeth. In both sexes there is a dorsal longi- 

 tudinal raised carina extending along the inner edge of the foretibia. 

 There is an irregular lateral extension of this carina onto the penulti- 

 mate external tooth somewhat similar to the carinal extension of 

 halyi (pi. 2, fig. 14). A row of setae is closely adjacent to the base of 

 the carina, briefly interrupted hj the carinal extension into the 

 penultimate external tooth. External face of tibia of meso- and 

 nietathoracic legs with three transverse carinae, the upper one small. 



