PREFACE. 
The present bulletin gives results of studies of the plum curculio 
that, with considerable interruption, have been in progress since the 
spring of 1905. The work has been done for the most part in con- 
junction with other investigations at the field laboratories in Decid- 
uous Fruit Insect Investigations, Bureau of Entomology, located in 
important fruit-growing sections and representing a considerable 
range of climatic and other conditions. Data have thus been ob- 
tained on the biology of the insect in northern, central, and southern 
localities in its range of distribution, as in western New York and 
northwestern Pennsylvania, in the environs of Washington, D. C, and 
in Georgia. Studies for one season were made in the Ozark region of 
Arkansas, well toward its limit of occurrence to the southwest. The 
observations presented, therefore, fairly well cover the distribution of 
the species, though for the respective localities the results are not 
entirely comparable, as for one reason or another it was found imprac- 
tical for the several workers Jto carry out uniformly the outline of 
studies originally prepared. 
In the case of but few native American insects are there earlier or 
more complete records of depredations than is true of the plum cur- 
culio. From the time of its first noted injuries, about 175 years ago, 
until the present day this insect has been execrated by commercial 
and amateur fruit growers alike. If we are to judge from the writings 
in the earlier horticultural and agricultural papers, it was especially 
despised by the early settlers for its destruction of choice varieties 
of plums and other stone fruits grown around their homes, and the 
number of remedies proposed was legion. Many workers have con- 
tributed to our present knowledge of the plum curculio, and their 
writings have been freely used in the present paper. Among these may 
be mentioned Fitch, Walsh, Riley, Trimble, Forbes, Howard, Weed, 
Stedman, Crandall, and others. 
Several members of the force engaged in Deciduous Fruit Insect 
Investigations have made important contributions to this report, as 
later credited in the text. Mr. James II. Beattie spent a part of the 
season of 1905 in Georgia, and Mr. A. A. Girault during the same year 
was engaged in life-history observations in the insect ary at Washing- 
ton. During 1906 Mr. Girault, with ^Ir. A. II. Rosenfeld, spent the 
season in Georgia working on the curculio and other peach insects, 
and the year following the former gentleman made observations on this 
insect in southern Ohio. Mr. Girault's careful studies have been of 
the greatest value. During 1905 Mr. Fred Johnson gave considerable 
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