DISPEESION OF GIPSY-MOTH LAKViE BY THE WIND. 19 
FEEDING OF LARVAE PRIOR TO DISPERSION BY THE WIND. 
Several of the first-stage caterpillars of various sizes caught on the 
screens during 1913 and 1914 were selected and examined for the 
presence of plant cells in the alimentary tract. As all caterpillars 
blown any reasonable distance by the wind are newly hatched, first- 
stage specimens, it is impossible to ascertain from a superficial ex- 
amination which have taken food and which have not. Before the 
examinations were made it was necessary to fix the material, stain 
with eosin and methylene blue, section with a microtome, and mount 
on slides, and this work was performed at Bussey Institute, Harvard 
"University, under the direction of Dr. R. W. Glaser of the Bureau of 
Entomology. 
Caterpillars were selected during the two seasons which had been 
borne by the wind a distance of 1, 2, and 6 or more miles, respec- 
tively, from the nearest source of infestation. Results were as 
follows : 
Table VI I. — Percentages of small caterpillars having fed which were caught on screens 
during 1913 and 1914. 
Year. 
Locality and distance carried by wind. 
Number of 
caterpillars 
that had 
fed. 
Number of 
caterpillars 
that had 
not fed. 
1913. 
1914. 
Salisbury Beach, Mass., 1 mile from infested woodland 
Isles of Shoals, N. H. Infestation in brushland around screen 
Plum Island, Mass.; 2 miles from infested woodland 
Isles of Shoals, N. H. ; 6 miles or more from infestation on the main 
land to the westward 
Merrimac, Mass.; \ to 1 mile from heavy infestation in all directions. 
Total 
Of the 45 small caterpillars prepared and examined during the two 
years that experiments were conducted, 23, or 51 per cent, had con- 
sumed a very small amount of food, while the remainder, 40 per 
cent, showed no signs of it. 
COMPARISON OF WEATHER DATA BETWEEN PROVIDENCE, R. I., AND 
AMHERST, MASS., WITH REFERENCE TO DISPERSION IN 1913. 
The period in which first-stage larvae were borne by the wind in 
1913 in eastern Massachusetts was from May 9 to June 5, inclusive. 
After comparing the hourly wind direction from 7 a. m. to 6 p. m. 
when there was no rain and the temperature was 50° F. or above at 
Providence, R. I., 1 and Amherst, Mass., 1 one notes a slight difference 
in the total wind movement in the various directions. For instance, 
in Providence the wind blew from the northwest 92 hours, from the 
1 The weather records at Providence were secured from the office of the U. S. Weather Bureau, and 
those at Amherst from the Experiment Station. 
