20 BULLETIN 273", U. S. DEPARTMENT OF AGRICULTURE. 
north 17, from the northeast 22, from the east 3, from the southeast 
51, from the south 37, from the southwest 1, and from the west 9 
hours during the foregoing period. In Amherst, Mass., it blew for the 
same period from the northwest 50 hours, from the north 51, from 
the northeast 9, from the east 2, from the southeast 30, from the south 
31, from the southwest 3, and from the west 46 hours. 
Providence was first found infested by the gipsy moth in 1901, 
and during the scouting season of 1913-14 egg clusters were found 
as far west as Woodstock, Pomfret, and Brooklyn, Conn. — a distance 
of 36 miles, or an average spread of 3 miles each year. It is apparent 
that this general infestation was not accomplished by direct east 
winds, as there are few recorded each year at the proper period, but 
by a combination of northeast and southeast winds transporting the 
larvse in a southwesterly and northwesterly direction from 1 to 10 
miles, thus gaining an average of 3 miles each year directly west. 
Although this insect has not yet reached Amherst, Mass., in its 
general sweep across the country, it occurs within a few miles to the 
eastward. A perusal of the wind records for the dispersion period 
of 1913 shows three times as many hours of north winds and about 
one-half as many northeast and southeast winds combined as are 
recorded in Providence, R. I. The total movement of northwest 
and west winds, which blow the larvse back into the infested terri- 
tory each year, is practically the same in the two localities. 
From this data it appears that the increase in the amount of north 
winds and the decrease in combined northeast and southeast winds 
at Amherst, when compared with the wind records at Providence, 
may result in a somewhat more rapid southwestern advance of the 
insect if it becomes established in the Connecticut Valley. More 
rapid southern and western spread is likely if the infestation reaches 
the Central States. 
SPREAD OF THE GIPSY MOTH IN NEW ENGLAND. 
The gipsy moth was introduced at Medford, Mass. (PI. VII), in 1869, 
from which point it has spread gradually over large areas in Massa- 
chusetts and other New England States, excepting Vermont. 1 Small 
infestations have also been located in New York, New Jersey, and 
Ohio, but these colonies are fast being exterminated. Extensive 
efforts to prevent spread have been carried on in Massachusetts by 
the State since 1890, with suspension of appropriations and efforts 
only from 1900 to 1905. Other infested States have appropriated 
smaller amounts which have aided in the suppression work. Con- 
gress began making appropriations hi 1906, and these annual sums 
have been expended to prevent spread and help control of the gipsy 
moth and the brown-tail moth. 
1 See, however, footnote on p. 17. 
