Ilbomas Xincoln Case^ 3Fun^ 



REVIEW OF THE GEXUS CHLAENOBIA BLANCHARD 

 ( COLEOPTERA : SCARABAEIDAE)' 



By EDWARD A. CHAPIN 



Curator, Division of Insects, U. S. N'atioiial Mitscion 



The tribe Rhizotrogini of the scarabaeid subfamily Melolonthinae 

 is represented in the New World by about 450 known species, dis- 

 tributed among what are usually considered as five genera. Somewhat 

 more than three-fourths of these species are assigned to Phyllophaga 

 Harris (Lachiiostcnia Hope). One species is the sole member of the 

 genus Chirodincs Bates. Listrochelus Blanchard and PJiytalus Erich- 

 son together number about 100 species. C lilac nobia Blanchard, as 

 defined in the present paper, contains 15 named forms, of which 2 

 are given but subspecific rank. 



In describing CJilacnobia, Blanchard allied it to certain genera 

 which are grouped about Macrodactylus Latreille. Lacordaire fol- 

 lowed Blanchard's suggestion in this matter. Bates, the first to have 

 an adequate series of specimens for study, recognized the genus as 

 Rhizotrogine and not Macrodactyline and so treated it in the Biologia 

 Centrali-Americana. Dalla Torre returned to the views of Blanchard 

 and Lacordaire in the Junk Catalog, but there is ample evidence to 

 show that this work is not at all critical. The present treatment of 

 the genus follows Bates. 



Arrow, in 1920, suggested that the American genus Phytalus 

 Erichson and the Asiatic genera Brahmina Blanchard and Holotrichia 

 Hope should be abandoned and their species placed in Lachnosterna 

 Hope {Phyllophaga Harris). If this is necessary, it is also necessary 

 to add those species now contained in Chlaenohia, for that genus is 

 certainly intimately connected with Phytalus. Chirodines is also very 

 close to Phytalus, and when its female is known, it may seem best to 

 add this geniis to Phyllophaga also. On the other hand, a study of 

 the Rhizotrogini may show that an entirely new grouping of the 



^ This is the second contribution to be published by the Smithsonian Institu- 

 tion under the Thomas Lincoln Casey Fund. 



Smithsonian Miscellaneous Collections, Vol. 94, No. 9 



