1961] 
Insect Control Programs 
79 
ACRES 
SPRAYED 
BY AIR 
Figure 2. Graphs to show the ups and downs of the struggle against the 
gypsy moth in the U. S. Acreage showing substantial defoliation by gypsy 
moth larvae each year (below) is compared with acreage sprayed from the 
air (above) mostly with DDT at 1 lb per acre. Some suppression treatments 
used only 1/2 or 3/4 lb of DDT per acre, and sevin has partly replaced 
DDT in recent years. For details, see summaries by USDA in Appendix A, 
upon which these graphs are based. 
