UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 436 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
February 7, 1917 
THE DESERT CORN FLEA-BEETLE. 
By V. L. Wildermuth, Entomological Assistant, Cereal and Forage Insect Investigations. 
CONTENTS. 
Introduction 1 
Distribution 2 
Economic considerations 2 
Food plants 4 
Descriptions 5 
Page. 
Life history and habits 7 
Seasonal history 15 
Natural enemies 16 
Remedial and preventive measures 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 ectypa Horn, 
which, 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 which 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 Valley of California in 1910, 
and during 1913, 1914, and 1915 has been conducted at Tempe, Ariz, 1 
The following pages comprise a report of these studies and obser- 
vations upon the economic status of this species in the Southwestern 
States. 
1 The writer was assisted during a part of the time by Messrs. R. N. Wilson, F. H. Gates, and L. J. 
Hogg, of the Bureau of Entomology. 
57154°— Bull. 436—17 1 
