UNITED STATES DEPARTMENT OF AGRICULTURE 



m BULLETIN No. 435 



Contribution from the Bureau of Entomology. 

 L. O. HOWARD, Chief. 



Washington, D. C. 



November 25, 1916 



THE APPLE LEAF-SEWER. 



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



CONTENTS. 



Page. 



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 



P?ge. 



Habits of moths 9 



Incubation of eggs 9 



Larval feeding period 10 



Hibernation 10 



Natural enemies 11 



Remedial measures 11 



Summary 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 foliage by the larva of this insect was 

 recorded by Riley as early as 1877, very little 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 sufficiently 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, under 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 biology of this 

 insect was made in the summer of 1914 and 1915. 



Note.— This bulletin will be found of value to apple growers in the North and Central Atlantic States, 

 the Middle West, and portions of Canada. 

 57166°— Bull. 435—16 



