BCJREAU OF ENTOMOLOGY AND PLANT QUARANTINE 11 
hours with methyl bromide at the rate of 3 to 4 pounds per 1,000 
cubic feet, and complete kill of these beetles was obtained. 
Earlier indications that toxic sprays would give practical control of 
ambrosia beetles in green logs and lumber were substantiated in ap- 
plications made under operating conditions in the woods and in 
the lumberyard. Hydraulic sprayers and fogging machines were 
used. Benzene hexachloride at 0.4-0.8 percent of the gamma isomer 
in fuel oil had given nearly complete protection to fresh-cut logs for 
2 to 4 months in tests still under way at the end of the year. Lumber 
was protected with a gamma-isomer concentration of only 0.1-0.2 
percent. 
New Program of Forest-Pest Surveys Organized 
Much time and effort have been devoted to organizing and planning 
a broad program of annual forest-pest surveys as authorized by the 
Forest Pest Control Act of 1947. The purpose of these surveys is 
to detect outbreaks before they become widespread and cause serious 
damage. It should then be possible to apply control measures at a 
reasonable cost and prevent the tremendous losses that have been far 
too common in past years. Funds for implementing this program 
have been provided for the fiscal year 1950. 
Gypsy Moths 
Cooperative programs expedite control 
The gypsy moth, a serious pest of forest and shade trees in the north- 
eastern part of the country for the last 60 years, can now be controlled 
with a single application of DDT. Such control has been made pos- 
sible by developing new methods of treatment utilizing new types of 
equipment and accomplished through organized cooperative programs. 
In addition to spray operations these programs include extensive sur- 
veys to determine the need for and the results of spraying. Not only 
have Federal and State agencies taken part in this program, but local 
communities, private agencies, and individuals have also participated. 
Airplanes are used to spray DDT over large forest areas, and mist 
blowers operated from the ground for treating trees in residential 
areas and along highways. Oil solutions of DDT are applied at the 
rate of 1 gallon per acre. One application of a 12-percent solution 
when the eggs are hatching is usually effective for an entire season. 
For any later spraying a 6-percent solution is used. The cost of all 
aerial spraying in 1949 was less than $1 per acre, and of spraying with 
mist blowers about 60 cents per acre. 
The last untreated portion of the infested Scranton- Wilkes-Bar re 
area in Pennsylvania, comprising about 135,000 acres, was sprayed 
by aircraft in 1948, and no more moths had been found there up to 
the end of June 1949. In the spring of 1949 most of the spraying in 
this area was done with mist blowers and knapsack pumps. However, 
more than 30,000 acres in the Quakertown section, about 60 miles south- 
east of Wilkes-Barre, where an isolated infestation was discovered 
by survey in the fall of 1948, were sprayed by aircraft. 
860448 — 49 3 
