NORTH AMERICAN GEOTRUPINAE — HOWDEN 305 



any surface litter near the burrow entrance, was so loosely packed 

 that it would begin to crumble as the encompassing sand was dug 

 away. The method of feces disposal of Peltoirupes youngi, which 

 has been described in detail under that species, also seems to be 

 different from any known Geotrupes. Certainly such biological differ- 

 ences should be considered to have some taxonomic value when 

 found in conjunction with good morphological characters, both in 

 the larvae and adults. 



Only the immature stages of gaigei in the genus Mycotrupes, the 

 last group of the North American Geotrupini to be discussed, are 

 known. Information on the larval biology is scanty. The larval 

 cells are found 5 or more feet deep, being composed of dung. Appar- 

 ently several cells branch off one burrow, but this may not always 

 be true. From the meager information at hand, the larval biology 

 of Mycotrupes appears to be similar to that of the North American 

 Geotrupes. The adults of all of the members of the genus are apterous 

 with fused elytra, superficially resembling some of the Lethrini. 

 They are found in isolated localities on some of the deep sand ridges 

 in the southeastern United States, and are active in the fall, winter, 

 and spring. Newly transformed adults appear during the early 

 spring. They have been noted feeding on fungi burrowing under 

 dung, and coming to fermenting malt or propionic acid placed in a 

 sunken can. I found Mycotrupes retusus LeConte in September in 

 3-foot burrows under stands of pine, but no larval cells were found 

 at that time. From the present available data the habits of all the 

 species appear to be quite similar. 



MISCELLANEOUS STUDIES 



Apparent economic damage caused by any of the groups seemingly 

 is slight, as there are few references to this aspect. The ravages of 

 Lethrus through its habit of leaf cutting have already been men- 

 tioned. Thomas (1939, pp. 23-24) mentions a reference to a 10 per- 

 cent loss of edible mushrooms. Boletus eduXis Fries, in south Germany 

 because of the activities of Geotrupes stercorosus Scriba. Wetzel 

 (1935, pp. 188-191) implicates Geotrupes sylvaticus as an intermediate 

 host of the fowl tapeworm, Davainea proglottina. 



As a group, the Geotrupinae seem to be more beneficial to man 

 than harmful, as they take a large amount of decaying material and 

 dung underground rather rapidly, but just how much value this has 

 remains an unanswered question. 



Several desultory studies have been conducted on some of the 

 Geotrupinae. Sharp and Muir (1912, p. 581) have discussed the 

 morphology of the male genitalia of a few species, while Hardenburg 

 (1907, pp. 548-602) and Mohr (1930, pp. 263-284) have compared 



