UNITED STATES DEPARTMENT OF AGRICULTURE 



BULLETIN No. 774 |Wlb 



Contribution from the Bureau of Entomology 

 J\?&' i &jru L. O. HOWARD, Chief 



Washington, D. C. PROFESSIONAL PAPER April 28, 1919 



LIFE HISTORY AND HABITS OF THE MEALY 

 PLUM APHIS. 



By W. M. Davidson, Scientific Assistant, Deciduous-Fruit Insect Investigations. 



Page. 



Origin 1 



Hosts and migratory habits 1 



Injury 2 



Synonyms 3 



Biology 3 



The egg 3 



The stem mother 3 



The spring forms 5 



CONTENTS. 



Page. 



B iology— C ontinued. 



The summer wingless forms 11 



The fall forms 12 



Natural enemies 14 



Control suggestions 15 



Summary 15 



Literature cited 16 



The mealy plum aphis (Hyalopterus arundinis Fabricius) has been 

 recognized for many years as an enemy of plums, prunes, and to a 

 lesser extent apricots in California. Since 1913 it has been espe- 

 cially severe in some regions, notably those in which artificial control 

 for the pear thrips (Taeniotkrips pyri Daniel) was not practiced. 



ORIGIN. 



The insect is European in origin, having been first described in 

 1794 by Fabricius. In North America it is widely distributed. Ac- 

 cording to Lowe (3) 1 it is present in Australia and New Zealand, Van 

 der Goot (2) reports it from Java, while the United States Bureau 

 of Entomology has records of its occurence in Japan. Specimens 

 in the writer's collection taken on Arundo in Peru, by Mr. E. W. 

 Rust, late of the Bureau of Entomology, appear to belong to this 

 species but the lack of winged forms prevents certain determination. 



HOSTS AND MIGRATORY HABITS. 



In California plums and prunes of the domestica type are the 

 favorite hosts, but apricots and Asiatic types of plums and rarely 



1 Figures in parenthesis refer to " Literature cited " on the final page of the bulletin. 

 98008°— Bull. 774—19 



