UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 805 



Contribution from the Bureau of Entomology 

 L. O. HOWARD, ClUef 



Washington, D. C. 



PROFESSIONAL PAPER 



December 15, 1919 



TWO LEAFHOPPERS INJURIOUS TO APPLE 

 NURSERY STOCK. 



By A. J. ACKERMAN, 



Scientific Assistant, Deciduous Fruit Insect Investigations. 



CONTENTS. 



Introduction 1 



The apple leafhopper 2 



History 2 



Distribution 2 



Food plants 3 



Character of injury 4 



Extent of injury and influencing factors 5 



Description of stages 5 



Allied species 6 



Life history and habits 7 



Siunmary of seasonal history 19 



Natural enemies 20 



The rose leafhopper 20 



History 20 



Synonymy 21 



Origin and distribution 21 



Food plants 21 



Character of injury 22 



Description of stages 22 



Life history and habits 23 



Summary of seasonal history 28 



Natural enemies 28 



Remedial measures 29 



Summary 33 



Literature cited 34 



INTRODUCTION. 



Serious injury to apple nursery stock due to the attack of leaf- 

 hoppers attracted the writer's attention while engaged in the investi- 

 gation of nursery fruit insects at West Chester, Pa. An examina- 

 tion of the injury showed the presence of two species of leaf hoppers, 

 the common apple leafhopper^ and the rose leafhopper.^ Further 

 study proved that each species produced a distinct type of injury, that 

 caused by the apple leafhopper being by far the more serious. The 

 conflicting nature of the entomological literature regarding the char- 

 acter of injury caused by these two species and their habits led the 

 writer, under the direction of Dr. A. L. Quaintance, of the Bureau of 

 Entomology, to undertake a study of their individual life histories 

 and the means for their control. 



1 Empoasca mali (Le Baron); order Hemiptera, suborder Homoptera, family CicadelHdae. 

 ' Empoa rosae (Linn.); order Hemiptera, suborder Homoptera, family Cicadellidae. 



132816"— 19 1 



