UNITED STATES DEPARTMENT OP AGRICULTURE 
BULLETIN No. 616 
Contribution from the Bureau of Entomology 
L. O. HOWARD, Chief 
Washington, D. C. 
PROFESSIONAL PAPER 
February 14, 1918 
THE CITRUS THRIPS 
By 
J. R. HORTON, Scientific Assistant 
CONTENTS 
Introduction 
History an£ Distribution . 
Nature and Extent of Injury 
Dissemination 
Food Plants 
Life History and Habits . . 
Page 
Page 
Seasonal History 22 
Natural Checks 24 
Natural Enemies 25 
Control Experiments 29 
Bibliography 41 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1918 
