UNITED STATES DEPARTMENT OF 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 



Introduction 



History and Distribution . 

 Nature and Extent of Injury 



Dissemination 



Food Plants 



CONTENTS 



Page 

 l 



3 



7 

 8 



Life History and Habits 10 



Page 



Seasonal History 22 



Natural Checks 24 



Natural Enemies 25 



Control Experiments 29 



Bibliography 41 



WASHINGTON 

 GOVERNMENT PRINTING OFFICE 



1918 



