VITTATE CHRYSOMELID BEETLES DISONYCHA — BLAKE 3 



gi'oup of beetles from the Amazon that Jacoby referred to Harold's 

 genus Nephrica. These do not have eyes any more reniform than 

 the other species of Disonycha. They are like C. quinguelineata in 

 that they are unusually large, and in their case broader than most but 

 not otherwise separable from other smaller species of Disonycha. 



Many of the groups of species represented in the United States by 

 only one species, such as D. glahrata (Fabricius), are found in greater 

 numbers in tropical America. D. glahrata itself extends with little 

 variation all the way from New York to Argentina. Drawings have 

 been made of the aedeagus from different localities in its long range 

 which show little difference throughout. The food plant, as is the 

 case of many species of Disonycha with blue elytra, is Amaranthus, a 

 widespread weed. Related to D. glahrata are several Central American 

 species, such as D. dorsaia Harold and D. nigrita Jacoby, and another 

 described in this publication. In South America is an even more 

 closely related species, D. vittipennis Boheman from Peru. 



On the other hand, the group of species that feeds on Salix is better 

 represented in the northern temperate regions. D. pluriligata (Le 

 Conte) and D. latiovittata Hatch of this group extend into Mexico and 

 Guatemala, and D. teapensis Blake is found only in Mexico, but the 

 group is not at all represented in South America to date. 



The group with costate elytra that feeds on Polygonum has a repre- 

 sentative in Mexico and Central America, D. reciicollis Jacoby, and 

 four in South America, one species from Peril, two from Brazil, and 

 one from Argentina, D. hicarinata Boheman, whose food habits have 

 been carefully studied by Frers, who found it living on Miihlenheckia, 

 one of the Polygonaceae. The food habits of the three other species 

 described in this publication are not known, but I venture to guess 

 that they also feed on plants of that family. 



The discoidea group is represented in Mexico and Central America 

 by D. militaris Jacoby, D. leptolineata texana Schaeffer, and D. 

 antennata Jacoby, and in South America by D. peruana Jacoby. 



In Argentina and adjacent countries occur a number of species with 

 very wide dark vittae, of which D. copulata (Germar) is representative. 



As in the United States, there are also many isolated species not at 

 all like any others. In time others may be collected that are related 

 to them. In working with so little material from such wide tropical 

 regions of Central and South America one has the constant thought 

 that only scattered specimens of a great genus are at hand. 



Common to the United States and Mexico and Central America 

 are 12 species, of which 4 occur only in States bordering on Mexico. 

 Common to Central America and South America are 6 species, half of 

 which occur only as far as Panama. I have described 8 new species 

 from Central America and Mexico, and 21 from South America. 



