UNITED STATES DEPARTMENT OF AGRICULTURE 



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BULLETIN No. 436 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



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Washington, D. C. 



PROFESSIONAL PAPER 



February 7, 1917 



THE DESERT CORN FLEA-BEETLE. 



By V. L. WiLDBEMUTH, Entomological Assistant, Cereal and Forage Insect Investigations. 



CONTENTS. 



Page. 



Introduction 1 



Distribution 2 



Economic considerations 2 



Food plants 4 



Descriptions 5 



Life history and habits 7 



Seasonal history 15 



Natural enemies 16 



Remedial and preventive measiu'es 18 



Summary 21 



INTRODUCTION. 



For a number of years past reports have been received by the 

 Bureau of Entomology of considerable damage to corn, milo maize, 

 and related crops by a small black beetle, Chaetocnema edypa Horn, 

 wliich, because of the fact that it is a native of the southwestern 

 desert regions, has been named the desert corn flea-beetle (fig. 1, p. 5). 



The writer first noted this small black beetle in the spring of 1910, 

 while located on a ranch in the extreme southern part of California. 

 In a field wMch had been planted to Indian corn, as an experiment 

 on the productiveness of this corn in the newly irrigated Imperial 

 Valley, it was noticed that within a few days after the corn came 

 through the ground the leaves became whitened and bleached, appar- 

 ently as a result of the work of some insect, and upon closer investi- 

 gation this beetle was found to be the cause. Subsequently the work 

 of this flea-beetle was noticed on various Egyptian corns and sorghums 

 as well as on sweet corn in various localities, not only in southern 

 California but also in southern Arizona and New Mexico. 



The study of the habits, life history, and methods of controlling 

 this insect was commenced in the Imperial VaUcy of California in 1910, 

 and during 1913, 1014, and 1915 has been conducted at Tempe, Ariz,' 



The following pages comprise a report of these studies and obser- 

 vations upon the economic status of this species in the Southwestern 

 States. 



' The writer was assisted during a part of the time by Messrs. R, N, Wilson, F. H. Gates, and L. J. 

 Uogg, of the liufpaij of Entomology. 

 67154*— Bull. 436-17 1 



