UNITED STATES DEPARTMENT OF AGRICULTURE 
DEPARTMENT BULLETIN No. 1205 
Washington, D. C. T January 25, 1924 
DUSTING AND SPRAYING PEACH TREES AFTER HARVEST FOR CONTROL 
OF THE PLUM CURCULIO. 1 
By Oliver I. Snapp, Entomologist, and C. H. Alden. -Scientific Assistant, Frui: 
Insect Investigations, Bureau of Entomology. 
CONTENTS. 
Page. Page. 
Results of experiments at Fort Valley, Ga., 
in 1921 2 
Jarring before dusting 2 
Dusting in 1921 4 
Jarring after dusting 4 
Results of insectary work in 1921 7 
Results of experiments at Fort Valley, Ga., 
in 1922 10 
Jarring before treatment 11 
Spraying and dusting in 1922 11 
Jarring after treatment 12 
Results of insectary work in 1922 14 
Other field and insectary observations in } General summary 17 
1921 10 ! Recommendations 18 
During the last four years ( 19 19-1922) post-harvest dusting 
experiments have been conducted in commercial peach orchards in 
the South to ascertain whether effective work can be done in destroy- 
ing adult curculios in the late summer or early fall when for lack of 
fruit the beetles are forced to feed to a great extent on the foliage. 
During one season also several plats were sprayed, in order to com- 
pare the effectiveness of sprays with that of dusts. The information 
obtained for the four consecutive seasons showed that the adult 
curculios can be materially reduced in the early fall by making post- 
harvest applications of arsenate of lead to the trees before the beetles 
leave them to hibernate. 
During the 1921 and 1922 seasons this work was conducted in the 
peach belt of Georgia, in the vicinity of Fort Valley, where the 
curculio infestation for several years had been much" more severe 
than elsewhere in the South. The work during the two previous 
years had been conducted in Mississippi. Since the results obtained 
during the last two seasons were the more complete and confirmed 
the results of the work conducted in Mississippi, only the data from 
the 1921 and 1922 experiments are discussed in detail in this bulletin. 
: Conotrachthts nenuphar Hbst.; order Coleqptera, family Curculionidae. 
62130°— 24— Bull. 1205 1 
