KEVISION OF THE BEETLES OF THE GENUS DISON YCHA 

 OCCURRING IN AMERICA NORTH OF MEXICO 



By Doris Holmes Blake 



Assistant Entomologist, Bureau of Entomology, United States Department of 



Agriculture 



HISTORY OF THE GENUS 



The generic name Disomjcha Chevrolat first appeared in the 

 Dejean Catalogue of 1837 ^ with 31 species listed under it. In 1844 

 Chevrolat - defined the genus as follows : 



Disonycha (5/s deux, '6vv^ ongle). Geure de Col^opt^res tetrameres, famille 

 des Cycliques, tribu des Alticites, cr^e par nous, et adopts par M. Dejean, qui, 

 daus son Catalogue, en enuniere 30 [sic] especes, dont 26 appartiennent k 

 I'Amerique, 3 & I'Afriqiie australe et une a I'Asie. Nous citerons, parrai les 

 premieres, les D. glahrata, conjugata, caroliniana et collaris (altica) de Fabricius, 

 5-lincata, 6-Uneata d'Olivier, et Jf-vittata d'lUiger. Les insectes qui composent 

 ce g. sont de moyeune grandeur ; presque tons ont les elytres noires avec 

 des lignes longitudinales jauues ; leurs tibias sont terniinfe ext^rieurement par 

 deux ongles excessivenient petits. 



Of the original 31 species listed in the Dejean Catalogue, at least 

 6 of the North and South American species had been previously 

 described, possibly more. Of these, only four are now considered as 

 belonging to the genus Dhonycha. Galleruca coUaris Fabricius ^ is 

 not recognizable, and Haltica quadrivittata Illiger * was listed b}'^ 

 Illiger under the group Oedipodes. The remainder are : Crioceris 

 caroliniana Fabricius,^ C. gJahnita Fabricius,*' C. collata Fabricius,'' 

 and Haltica conjuncta Germar.^ Since no previous designation 

 seems to have been made, Crioceris collata^ the most definitely de- 

 scribed of the North American species included by Chevrolat (in 

 Dejean), is hereby designated as the type of the genus. 



1 Catalogue des col^optferes de la collection de M. le Comte Dejean, p. 414, 1837. 



2 D'Orbigny, Dictionnaire universel d'histoire naturelle, vol. 5, p. 81, 1844. 

 = Fabricius, Entomologia systematica, suppl., p. 97, 1798. 



* Illiger, Mag. fiir Insekt., vol. 6, p. 106, 1807. 

 "Fabricius, Systema entomologiae, p. 122, 1775. 



* Fabriciu.s, Species insectorum, vol. 1, p. 156, 1781. 

 'Fabricius, Systema Eleutlieratorum, vol. 1, p. 463, 1801. 



* Germar, Insectorum species, p. 610, 1824. 



No. 2969.— Proceedings U. S. National Museum. Vol. 82, Art. 28 



17.5870—33 1 



