UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 435 



yfZ, Contribution from the Bureau of Entomology. ^ 



^^.^^ L. O. HOWARD, Chief. JZf^^^^U 



Washington, D. C. 



November 25, 1916 



THE APPLE LEAF-SEWER. 



By B. R. Leach, Scientific Assistant, Deciduous Fruit Insect Investigations. 



CONTENTS. 



Introduction 1 



History 2 



Distribution 2 



Feeding habits and character of injury 2 



Description of stages 4 



Spring pupation of wintering larvae '. 6 



Emergence of moths 7 



Oviposition of moths 8 



Length of life of moths 8 



Habits of moths 9 



Incubation of eggs 9 



Larval feeding period 10 



Hibernation lo 



Natiu-al enemies 11 



Remedial measures 11 



Siunmary 12 



Bibliography 13 



INTRODUCTION. 



. In the summer of 1914, while engaged in deciduous-fruit insect 

 investigations at Winchester, Va., the writer's attention was attracted 

 by the common occurrence of the apple leaf -sewer, Ancylis nuheculana 

 Clemens, sometimes termed the apple leaf-folder, upon apple foliage. 



Although injury to apple foUage by the larva of this insect was 

 recorded by Riley as early as 1877, very Uttle concerning it has been 

 published since. This apparent lack of attention may be attributed 

 to the fact that although common and widely distributed, it has 

 occurred so far only at infrequent intervals in sufhcientiy large num- 

 bers to cause serious damage and attract special notice to it, as an 

 economic pest. 



The feeding habits of the larva, while interesting when contrasted 

 with those of other leaf-inhabiting species, are such as, imder certain 

 conditions, render the insect capable of considerable damage to the 

 foliage of the apple, especially in young orchards receiving indifferent 

 care. At the suggestion and under the direction of Dr. A. L. Quain- 

 tance, of the Bureau of Entomology, the study of the ])iology of this 

 insect was made in the sumiiKu- of \\)\A and 101 .5. 



NoTF..— This bulletin will bo found of value to applo (jrowers in the North and Central Adanl ic States, 

 the Mlddln Wfr ;t , ;ind portions of (Canada. 

 671fXi°-I5iJll. 4:{:>— 10 



