170 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



Mr, E. 0. G. Kelly: I will answer that by saying that the winds 

 are very light when flies are flying, and during a strong wind the adults 

 will cling close to the plants. The records I have were made at Wel- 

 lington. The days on which we caught the flies, the wind velocity was 

 less than twenty miles per hour. If the wind is higher than that, not 

 many flies are caught. 



Mr. J. W. McColloch: The records of the station bear out what 

 Mr. Kelly just said — twenty miles is the maximum velocity. 



President C. Gordon Hewitt: If there is no further discussion, 

 we will close the reading of papers for the session. 



(After conducting routine business the session adjourned.) 



Afternoon Session, Saturday, December 30, 1916, 2.10 p. m. 



President C. Gordon Hewitt: The first paper on the program 

 will be presented by Mr. C. W. Collins: 



METHODS USED IN DETERMINING WIND DISPERSION OF 

 THE GIPSY MOTH AND SOME OTHER INSECTS^ 



By C. W. Collins, Bureau of Entomology, U. S. Department of Agriculture 



In 1910, some experiments were begun at the Gipsy Moth Laboratory 

 to determine if, and to what extent, gipsy moth caterpillars were 

 carried by the wind. These had their inception in a small way by al- 

 lowing the newly hatched larvae to spin or drop into a current of air 

 circulated by an electric fan. In this experiment the larvae were 

 buoyed up and could be seen floating from one room through another. 

 These experiments were enlarged upon later in the season by using small 

 poultry wire screens treated with tanglefoot. They were set up on a 

 salt marsh area. Newly hatched larvae were liberated from boxes 

 fastened to a stake at given distances from the screen in the opposite 

 direction the wind was blowing. Larvae were caught on these screens 

 at distances varying from 50 to 1,833 feet from liberation point and 

 these were followed by larger experiments, the details of which, with 

 other notes on dispersion of the gipsy moth, have been published by 

 Burgess,^ and later results by the writer.^ Stabler^ and his associate 



1 Published by permission of the Chief of the U. S. Bureau of Entomology. Other 

 illustrations of methods used in dispersion experiments will be found in Bui. 273, 

 Bur. Ent., U. S. D. A., 1915. 



2 Burgess, A. F. The Dispersion of the Gipsy Moth. Bui. 119, Bur. Ent., 

 U.S.D.A., 1913. 



3 ColUns, C. W. Dispersion of Gipsy Moth Larvaj by the Wind. Bui. 273, Bur. 

 Ent., U. S. D. A., 1915. 



* Stabler, H. P. Red Spiders Spread by the Wind. Mo. Bui. Cal. Hort. Com., II: 

 12 p. 777, 1913. 



