BUREAU OF ENTOMOLOGY AXD PLANT QUARANTINE 19 
acres, was sprayed by aircraft to eradicate the moth there and inci- 
dentally keep wind-borne larvae from reinfesting nearby Barnstable 
County. 
Defoliated acreage lowest in 25 years 
Field observations by Federal and cooperating State agencies showed 
a total of only 5,400 acres defoliated by the gypsy moth in the summer 
of 1950 — the' lowest reported since 1924, when only 825 acres were 
defoliated. Extensive use of aircraft and mist blowers in spraying 
areas of heaviest population was the most important factor in the 
reduction. Parasites, predators, and wilt disease, along with a heavy 
mortality of newly hatched larvae as a result of a cold, wet period in 
May 1950, also contributed to the reduction. The winter of 1950-51 
was mild and otherwise favorable for gypsy moth survival. 
Simplified certification procedures approved by shippers 
Various means were used to simplify compliance with the require- 
ments of the gy\^y moth quarantine by producers and shippers. 
Growers applied DDT to 460 acres in and around nurseries to assure 
noninfested stock. Some 22,700 cords of pulpwood and fuel wood 
were moved under limited permits on the basis of immediate con- 
sumption of the wood at destination. Upon determination that con- 
ditions at either producing or processing sites would insure against 
the spread or establishment of the moth, 590 establishments were au- 
thorized to operate under certification agreements. Advance scout- 
ing showed 50,000 acres of lumber and pulpwood areas to be free 
from infestation. Products from this acreage were eligible for cer- 
tification when cut. State agencies and shippers cooperated in the 
fumigation with methyl bromide of 266,000 Christmas trees. More 
than 450 tourist camps, scrap-metal yards, and gas-cylinder establish- 
ments were scouted. The owners of 51 such establishments destroyed 
moth infestations on their properties. 
^Quantities of products certified for movement from eastern Xew 
York and Xew England to markets and consumers throughout the 
United States and Canada greatly exceeded those of the previous 
year. Products certified during the fiscal year included 301 million 
board feet of lumber. 400,000 logs and poles.' 75,500 cords of pulpwood 
and fuel wood, and 220,000 bales of excelsior and shavings. Nearly 
.37 million nursery and field-grown plants, 420.000 Christmas trees, 
and 93,000 bundles of evergreen boughs were certified as free of the 
gypsy moth and shipped to nonregulated areas. Certified quarry 
products included 335,000 tons of stone and granite and 338,000 pieces 
of monument materials. Articles certified had an estimated value 
of S54.000.000. 
Inspectors stationed near the boundaries of the regulated area in 
periods of heavy movement of regulated products prevented the trans- 
portation to noninfested points of 145 shipments of uncertified 
products. 
Heat take-off from automobile speeds fumigation 
Methyl-bromide fumigation of refrigerator cars as a condition 
for gypsy moth certification was expedited and greatly simplified by 
the development of a hot-water volatilizer for the gas. The vol- 
