44 PROCEEDINGS OF THE NATIONAL MUSEUM vol. ui 



Keys based on morphological differences of the known larvae of 

 Aphodiinae of the United States are presented for separating tribes, 

 genera, and species. Morphological differences of the epipharynges, 

 maxillae, rasters, and lower anal lobes are used. Before the present 

 study was undertaken, unnamed larvae of the Aphodiinae could not 

 be assigned below the subfamily level. Now, for the first time, 

 adequate keys permit separation of the fom* tribes and of 9 of the 15 

 genera found in the United States. 



Larvae of four genera,— Aegialia, Aphotaenius, Euparia, and 

 Pleurophorus — are described for the first time from reared material 

 and are included with Aphodin^, Oxyomus, Saprosites, Ataenius, and 

 Psammodius in the present study. 



It is unfortunate that reared material of the remaining genera and 

 of more species of the included genera was not available for study. 

 Relatively extremely little reared material has been accumulated by 

 any individual or institution. Every available known larva was 

 examined. 



Larvae of six genera of Aphodiinae from the United States are yet 

 to be recognized and described. Larvae of Dialytes, Dialytellus, 

 Pseudataenius, Rhyssemus, Trichiorhyssemus, and Alicroaegialia are 

 unknown. 



The larvae of Aegialia show close similarities with the larvae of 

 Aphodiinae and in this work have been treated under the subfamily 

 Aphodiinae in a new tribe. On the basis of larval characters the 

 tribes of Aphodiinae can be arranged in the following order: Aegialiini, 

 Aphodiini, Eupariini, and Psanmiodiini. 



Review of Literatube 



The earliest paper on the larvae of Aphodiinae appeared in 1835, 

 when De Hann (1835) described and discussed briefly the systematic 

 position of Aphodius luridus Fabricius and A. conjugatus Panzer 

 larvae. Mulsant (1842) briefly characterized the larvae of Aphodius 

 distinctus Miiller, A. satellitus Herbst, and A. varians Duftschmid. 

 In 1871 he characterized larvae of Aphodius jimetarius (Linnaeus). 



Schiodte (1874) gave diagrams and distinguishing larval characters 

 for Aphodius rufipes (Linnaeus), A. granarius (Linnaeus), A. fossor 

 (Linnaeus), and A. brevis Erichson. Perris (1877) published brief 

 descriptions of Aphodius fossor (Linnaeus) and -A. constans Duftschmid. 

 Rosenhaiu (1882) described and gave a key for six species of the 

 genus Aphodius, but he used the characters of color and width of 

 head capsule, which are not reliable. Hansen (1925) gave distinguish- 

 ing characters for larvae of the genus Aphodius and wrote short 

 descriptions for eight species. 



