78 
Psyche 
[J une-September 
Control Problems 
Early control efforts by the State of Massachusetts and the Federal 
Government included laborious and expensive methods such as hand- 
creosoting of egg masses, shelter-band and tanglefoot trapping on tree 
trunks, and various kinds of spray operations from the ground. For 
many years, control and quarantine programs appear to have confined 
the infestation to the area east of the “barrier” at the Berkshires and 
Green Mountains. Occasional extralimital infestations appearing in 
New Jersey, Ohio, Pennsylvania and Canada, particularly after egg 
masses were spread widely by the hurricane of 1938, apparently were 
eradicated before getting out of hand. Extensive introductions of 
predatory and parasitic insects from Europe and Japan were made 
beginning in 1905, and about ten such insects have taken hold in 
North America. Much of the subsequent history of the infestation 
was summarized in the report of the Gypsy Moth Eradication 
Meeting 11 held in Ithaca, New York, in September, 1957: 
“Following World War II, DDT was found to be a specific 
insecticide for the gypsy moth. At about the same time applica- 
tion of insecticide by plane became a practical undertaking. It 
was a new day for gypsy moth control. Heavy infestations 
within the area of general spread were suppressed or brought 
under control, and new infestations beyond the barrier were 
detected and held in check. Pennsylvania eradicated with reason- 
able effort and expenditure the gypsy moth on an area of 300,000 
acres. Unfortunately more than 20 million acres were infested 
in this country before a practical control was discovered. 
For some unexplained reason, the gypsy moth infestations seemed 
to explode* in 1950 and there was rapid spread beyond the bar- 
rier zone. Following the outbreaks in 1953 and 1954, surveys 
revealed the new areas of infestation west of the barrier zone 
in New York, New Jersey and Pennsylvania, aggregating nearly 
9 million acres. An isolated infestation found in the vicinity of 
Fansing, Michigan, was immediately scheduled for eradication. 
The occurrence of these infestations west and south of the barrier 
posed a serious threat of spread to the hardwood forests through- 
out the eastern and southern United States. The control and 
quarantine programs that had successfully held the moth in check 
for so long were no longer adequate. ...” 
*The explosion might better be said to have fairly begun in 1951 or 1952; 
see Figure 2. Its inception so soon after mass air spraying of DDT began 
on an operational basis is a phenomenon which, curiously enough, seems to 
have attracted little attention. It was first pointed out to me by Prof. F. M. 
Carpenter of Harvard University. — W. L. B. 
