NORTH AMERICAN GEOTRUPINAE — ^HOWDEN 263 



One or two incomplete carinae are also present. Tarsal claws similar 

 in both sexes. 



Genital capsule and genitalia of male large, most of the elaborately 

 sinuate parameres enclosed dorsally and ventrally by the phallobase 

 (pi. 4, fig. 2), which is somewhat similar in structure to that of balyi 

 and hornii. 



Variation in the specimens examined was not great. Size and 

 number and density of the coarse head and pronotal punctures showed 

 the greatest differences, but the species appears quite uniform. No 

 consistent differences were noted between New Brunswick and 

 European specimens. 



This species can be distinguished from other North American species 

 by its generally large size, poorly punctured elytral striae, the sutural 

 stria continued around the scutellum to the elytral base with the second 

 stria not extending to elytral base (differing from other North Ameri- 

 can species except for balyi and hornii), the second segment of the 

 antennal club strongly emarginate, the structure of the male genitalia 

 (pi. 4, fig. 2), and the bright purple or blue iridescence of the ventral 

 surface. 



While the biology of Geotrupes stercorarius has not been studied 

 in North America, there have been numerous observations made on its 

 life history in Europe where it is widely distributed, ranging from 

 Great Britain (Curtis, 1829, page opposite plate 266) to Russia 

 (Lebedeva, 1906, p. 436). However, due to nomenclatorial confusion, 

 any references to this species must be used with caution, as is pointed 

 out by Main (1917, p. 18): 



... it is by no means certain that the beetle we now call G. stercorarius is the 

 species referred to by Fabre or other earlier writers by that name. Hence, ap- 

 parent discrepancies in the records of various authors about an insect may be due 

 to the fact that different species are being referred to under the same name. As 

 a case in point, Fabre gives the autumn as the time of oviposition of G. stercorarius, 

 while the insect which now goes by this name lays its eggs in the spring, and it is 

 our [British] G. spiniger, whose name he does not mention, which lays its eggs in 

 the autumn. . . . 



It might also be put on record that the interesting account of the parasitism of 

 Aphodius porcus, related by Dr. Chapman in the "E. M. M.," 1869, pp. 273-276, 

 should be referred to G. spiniger Marsh, as the host, and not G. stercorarius L., 

 the names having certainly been transposed since the date of the published 

 account. 



Several good, fairly recent papers dealing entirely or in part with the 

 biology of Geotrupes stercorarius are Spaney (1910, pp. 625-634), 

 Sano (1915-1916, pp. 25-28), Main (1917, pp. 18-22), and Schjelderup- 

 Ebbe (1925, pp. 97-98). Some of the information set forth in these 

 papers is briefly summarized here. 



Geotrupes stercorarius has been noted as using horse or cow dung for 

 larval and adult food. Egg laying occurs in the spring and early 



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