Suppression of the Gipsy and Brown-tail Moths. 3 



were defoliated during the early summer. Matters became 

 so serious in 1905 that work was resumed by the Common- 

 wealth of Massachusetts, but the law was framed in such a 

 way that not only the State but the towns and cities and the 

 owners of property were required to give financial support 

 to the undertaking. 



During the period when no work was being carried on by 

 the State of Massachusetts the insects spread to Rhode 

 Island, Xew Hampshire, and Maine, making the problem 

 far more serious than before. In 1906 funds were appropri- 

 ated by Congress to prevent the spread of these insects, and 

 since that time Federal work for this purpose has been 

 continued. It is true that both insects have spread over a 

 much larger area since this work began, but that was to be 

 expected, owing to the necessity of properly organizing the 

 work and developing new and better methods for handling 

 the problem on a scale unprecedented for insect control. 



The gipsy moth and the brown-tail moth occur in greater 

 or less numbers in all the New England States. The dis- 

 persion of the brown-tail moth covers a larger area than that 

 of the gipsy moth, because both sexes of the brown-tail fly 

 freely and, this being the case, it is very difficult to prevent 

 their spread. These white moths are attracted to strong 

 light, particularly electric arc lights, and about the 10th 

 of July of each year they can usually be found in badly 

 infested regions on poles, trees, or buildings near these 

 lights. The extent to which they spread at this time depends 

 largely on the temperature and the direction and velocity of 

 the wind. These moths have been taken *on the Nantucket 

 Shoals lightship, which is 42 nautical miles from Nantucket, 

 the nearest land, and as the infestation of that island by this 

 insect, is very slight it is probable that the moths came from 

 a much greater distance. Frequent reports have been re- 

 ceived from captains of sailing vessels that swarms of these 

 moths have been encountered from 75 to 100 miles out at 

 sea, although there is a possibility that there may have been 

 a mistake in identifying the insect. These facts indicate 

 that the possibility of rapid spread, so far as this insect is 

 concerned, is very great, provided high temperature and 

 favorable winds occur when the moths are flying. Fortu- 

 nately, the prevailing winds in New England during early 

 July are from a southerly or southwesterly direction, which 



