GYPSY AXD BROWX-TAIL MOTHS AXD THEIR CONTROL 5 



Scouting during the latter half of 1929 and the first half of 1930 

 showed a further increase in the number of infestations in the barrier 

 zone, and Congress made additional funds available for clean-up 

 work. No provision was made, however, for examination of terri- 

 tory immediately east of the zone to check the increase there. The 

 infestations located in 1929 and 1930 were new ones, as most of those 

 previously discovered had been cleaned up. 



In 1933, after the passage of the National Industrial Recovery Act, 

 funds were made available and extensive scouting and clean-up work 

 was undertaken between the barrier zone and the Connecticut River. 

 This was extended very materially by personnel from certain Civilian 

 Conservation Corps camps, which were supervised by the gypsy moth 

 organization of the Bureau of Entomology and Plant Quarantine 

 through cooperative arrangements with the Forest Service of the 

 United States Department of Agriculture, the State forest services, 

 and the United States Department of the Interior. 



The prompt elimination of a few sporadic colonies that had been 

 found just beyond the zone, together with the suitability of the area 

 in the zone for effective clean-up, offers conclusive proof of the feas- 

 ibility of checking westward spread. 



In 1934 a change in quarantine was made by transferring from the 

 lightly to the generally infested area 74 towns in Maine, 5 in New 

 Hampshire, 2 in Vermont, and 3 in Connecticut. In northern Ver- 

 mont 39 towns were dropped from quarantine. The barrier zone 

 line in northeastern New York was relocated on the New York- 

 Vermont State line, thus eliminating 807 square miles, and a strip of 

 towns in Vermont adjoining the barrier zone on the east, aggregating 

 604 square miles, was added to the zone. 



Since July 1935 emergency funds have been made available for 

 gypsy moth work, and more scouting and clean-up work has been 

 carried on than heretofore. This has suppressed the insect in many 

 isolated colonies and improved the condition in the barrier zone and 

 the area adjoining it to the east. 



CONDITIONS OF INFESTATION IN NEW ENGLAND 



From the beginning of its gypsy moth work the Bureau of Ento- 

 mology obtained general records of the density of local and general 

 infestations in the territory not covered by the Bureau. Since 1911, 

 however, counts of egg clusters have been taken annually from a 

 series of woodland plots in the eastern portion of the infested area. 

 Thev are summarized as follows: 



Egg clusters 

 Year per acre 



1911 5,214 



1912 5,407 



1913 2,635 



1914 3,658 



1915 4,400 



1916 3,751 



1917 3, 702 



1918 2, 273 



1919 4,032 



1920 2, 134 



1921 2. 387 



1922 402 



Year 



1923. 



1924. 



1925. 



1926. 



1927. 



1928. 



1929. 



1930. 



1931. 



1932. 



1933. 



1934. 



Egg clusters 

 per acre 



110 



50 



61 



127 



303 



722 



__ 407 



66 



42 



__ 112 



344 



__ 181 



