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CIRCULAE 4 64, U. S. DEPARTMENT OE AGRICULTURE 



Scouting during the fall of 1920 and the spring of 1921, financed 

 by the State of New Jersey and the Federal Government, revealed 

 infestations of this insect in scattered localities over an area of more 

 than 400 square miles surrounding Somerville (fig. 14). 



Figure 14.— Area in New Jersey infested by the gypsy moth in 1921. Dots indicate location of colonies 

 within the infested area, and dots enclosed in circles indicate isolated colonies. 



Previous successes in cleaning up local infestations led to the 

 adoption of a cooperative plan to clean up this large, newly discovered 

 infestation. State and Federal funds were appropriated, and the 

 work was organized under the direction of the field office for gypsy 

 moth control of the Bureau of Entomology. When the limits of 

 infestation had been determined, the area was placed under State 

 quarantine, which required as a condition of movement the certifica- 

 tion of freedom from infestation of all products likely to carry any 

 stage of the gypsy moth. Thorough inspection, which permitted 

 certification, was made in cooperation with the Federal Government and 

 by Federal inspectors. The area under regulation has been gradually 

 reduced as a result of the clean-up work, and in 1932 Federal opera- 

 tions were stopped and all inspection requirements were withdrawn. 



As soon as active work was under way in New Jersey, it was learned 

 that trees had been shipped from the estate on which the insect was 

 first discovered, and that the danger of its establishment in many 



