) 
i SD ALB. hy Bal. 68; Part IX. D. F. I. I., February 11, 1909. 
PAPERS ON DECIDUOUS FRUIT INSECTS AND INSECTICIDES. 
THE PEACH-TREE BARKBEETLE. 
(Phleotribus liminaris Harr.) 
By H. F. WILson, 
Engaged in Deciduous Fruit Insect Investigations. 
INTRODUCTION. 
By way of introduction 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 last four 
or five years this insect has been doing a great amount of injury to 
apparently healthy trees. The history of Scolytide 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 accom- 
plish considerable injury. Such seems to be the history of Phl@o- 
tribus liminaris. 
The attention of Prof. H. A. Gossard, of the Ohio Agricultural 
Experiment Station, was called to this insect by Mr. W. H. Wright, 
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 Ph/@otribus 
liminaris. 
At the instance of Professor Gossard, investigation of this species 
was undertaken in the spring of 1908 by the Bureau of Entomology 
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 se- 
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 
fairly complete for a single season’s work. 
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