UNITED STATES DEPARTMENT OF AGRICULTURE 



Washington, D. C. 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, Chief 



PROFESSIONAL PAPER 



December 21, 1920 



CLOVER-LEAF WEEVIL. 



By 



D. G. Tower and F. A. Fenton, 

 Cereal and Forage Crop Insect Investigations. 



CONTENTS. 



Page. 



Introductory 1 



Distribution 1 



Description 2 



Adult 2 



Egg 3 



Larva 3 



Cocoon 5 



Pupa 5 



Pood plants and injury - 6 



Page. 



Life history 6 



Life cycle 6 



Copulation 11 



Ovipositian . . . 11 



Habits 12 



Feeding experiments 12 



Natural enemies 16 



Control 18 



Literature cited 1.3 



INTRODUCTORY. 



The clover-leaf weevil, Hypera 'punctata Fab. (fig. 1), ranks as 

 one of the important clover pests. Although it is usually unnoticed, 

 it annually exacts its toll of the crop. It seldom devastates entire 

 fields, however, because the larvae are ordinarily checked by an 

 ever-present fungous disease which spreads rapidly and reduces their 

 numbers to a negligible quantity in a remarkably short time. 



DISTRIBUTION. 



This insect was introduced accidentally into this country from 

 Europe, where it is well known. It also occurs in northern Asia and 

 probably in central Asia and China. So far as known it is the only 

 species of Hypera that has reached this country, the genus being 

 indigenous to the eastern hemisphere. 



The first record of Hypera punctata occurring as a pest in the 

 United States was in 1881 when a severe outbreak occurred at Bar- 

 rington, N. Y. A single specimen taken about 1850-1855 in Canada 

 by the Geological Survey and identified by Dr. LeConte in 1876 

 shows that this species had been in America for some time before 

 becoming noticeable or seriously injurious. 



15131°— 20— Bull. 922 1 



