UNITED STATES DEPARTMENT OF AGRICULTURE 



In Cooperation with the 

 Connecticut Agricultural Experiment Station 



DEPARTMENT BULLETIN No. 1238 



Washington, D. C. T October 15, 1924 



THE CANKERWORMS 



By 



B. A. PORTER, Entomologist, and 



C. H. ALDEN, Scientific Assistant, Fruit Insect Investigations, 



Bureau of Entomology 



i CONTENTS 



P»ge 



Introduction 1. 



Economic History • 2 



Scientific History 3 



Common Names . 4 



Differences Between the Species 5 



Food Plants 5 



Distribution 6 



Means of Dissemination 6 



Economic Importance 8 



Fall Cankerworm 9 



Spring Cankerworm 20 



Natural Control 28 



Control Measures 32 



Summary 35 



Literature Cited 36 



WASHINGTON 

 GOVERNMENT PRINTING OFFICE 



1924 



