r. S. I). A.. I'.. K. I'.iil. lis. I'ari IX. D. F. I. I., February 11, IDO'.). 



PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 



THE PEACH-TREE BARKBEETLE. 



(PhloFOtrihiiK lintiiKiris TTarr.) 



I!\ 11. F. \\ii.S(..\. 

 Engai/iit in DccidKoiis I'riiil liis<<l ] nrcslifinlioiis. 



INTRODUCTION. 



By way of introductioji it is perhaps necessary to give an account 

 of the present degree of importance, from an economic standpoint, 

 which this beetle has reached in northern Ohio. For the hist four 

 or five years this insect has been doing a great amount of injur}' to 

 apparently healthy trees. The histor}^ of Scolytidir in general shows 

 that certain species may be present in orchards for years without 

 doing any appreciable damage. Then, owing to favorable climatic 

 or other conditions, they may develop in large numbers and accoui- 

 plish considerable injury. Such seems to be the history of PhJceo- 

 trihus Uniinaris. 



The attention of Prof. H. A. Gossard, of the Ohio Agricultural 

 Experiment Station, was called to this insect bj^ Mr. AV. H. AVright, 

 in charge of a large farm at Lakeside, Ohio, Mr. Wright having 

 reported to him that large blocks of peach trees in the orchard were 

 dying from an unknown cause. Upon investigation Professor Gos- 

 sard found that this orchard was seriously infested with PhhyotHh>is 

 liminaris. 



At the instance of Professor (jlossard, investigation of this sjjccies 

 was undertaken in the spring of lOOS by the I^u.reau of P^ntomology 

 in cooperation with the Ohio Agricultural Experiment Station, and 

 the writer, representing the Bureau, and working under the joint 

 direction of Professors Gossard and Quaintance. was assigned to 

 the work, with headquarters at Lakeside, Ohio. Through the courtesy 

 of Mr. Wright a suitable building and experimental orchards were so- 

 cured. All breeding cages were kept under out-of-door conditions, 

 and as far as possible outside conditions were watched in comparison 

 with those in the breeding cages. Data were secured on all stages of 

 development of the insect, and the results obtained are considered 



fairlv complete for a single season's work. 



91 



