DISPERSION OF GIPSY-MOTH LARViE BY THE WIND. 
7 
quarantine line for experiments intended to explain the sources of 
many infestations found under such conditions. 
Screens of poultry wire, to which tanglefoot was applied, were 
erected in three of the selected locations along the coast and on the 
. Isles of Shoals (PI. II). Those used in the New Hampshire hill ex- 
[ periments were of a somewhat different type and are described 
under that head. The screens used along the coast (PL III, fig. 1) 
were of J^-inch mesh poultry wire stapled to 2 by 4 posts which 
were set in the ground and held in place at the top by guy wires and 
wooden braces. The posts were 12 feet high and two sections of wire 
each 75 feet long and 3 feet wide were fastened to these so that the 
top selvage was 12 and the lower 6 feet from the ground. The 
screens contained 450 square feet of wire and were built in three 
25-foot sections, the middle section facing the west and the other 
. two angling from the ends about 45° to the eastward. This gave 
the greatest exposure at all times to the northwest, west, and south- 
west winds. A runway was attached to the posts at the bottom 
selvage of the wire to facilitate examinations. 
HATCHING OF EGGS IN RELATION TO WIND DISPERSION OF FIRST- 
STAGE LARVAE. 
Close observations on the time of hatching of egg clusters in the 
field have been kept since 1912 by laboratory men stationed in 
different sections of Massachusetts and New Hampshire. The data 
consulted were collected by Messrs. E. A. Proctor in northeastern 
Massachusetts, J. V. Schaffner, jr., in Massachusetts south and south- 
west of Boston, and I. L. Bailey in south-central New Hampshire. 
Table I. — First, maximum, and last dates of hatching in 1912, 1913, and 1914. 
Year. 
Northeastern Massachusetts 
hatching. 
Southeastern Massachusetts 
hatching. 
South-central New Hamp- 
shire hatching. 
First. 
Maxi- 
mum. 
Last. 
First. 
Maxi- 
mum. 
Last. 
First. 
Maxi- 
mum. 
Last. 
1912 
1914 
Mav 2 
Apr. 25 
May 11 
May 11 
May 5 
May 15 
May 22 
May 27 
May 28 
May 1 
Apr. 26 
May 9 
May 15 
May 10 
May 15 
May 25 
May 21 
May 23 
May 1 
Apr. 29 
May 11 
May 14 
May 8 
May 16 
May 23 
May 14 
May 28 
The first larvae were caught on the screen in northeastern Massa- 
i chusetts May 9, 1913, and the last June 5, while the largest numbers 
were removed between May 14 and June 1. During 1914 in the 
same section the first larva was caught about May 16, while the 
largest numbers were removed from May 20 to May 27 and the last 
June 6. One larva was caught in Henniker, N. H., as late as June 
13, 1914. 
In a year of normal hatching, as in 1913, wind dispersion was 
noted about two weeks after first hatching and one week after hatch- 
