New York Agricultural Experiment Station. 557 



the Gipsy Moth Commission. It has also been recommended as a 

 remedy for insects of similar habits to the cottonwood leaf beetle. 



In Bulletin 103 of the New Jersey Agricultural Experiment 

 Station, in connection with a discussion of the elm-leaf beetle, 

 Prof. J. B. Smith says of this material : " It is formed by adding 

 four ounces arsenate of soda and eleven ounces acetate lead to one 

 hundred gallons of water. The chemicals dissolve readily and unite 

 to form a white precipitate which is arsenate of lead, and which 

 remains in suspension a long time, settling very slowly, and thus 

 requiring less stirring than either Paris green or London purple. 

 Two quarts of glucose or molasses to one hundred gallons of the 

 mixture will add so greatly to its sticking qualities that even a heavy 

 shower will not wash it off completely." If a less amount is 

 desired, it may be formed in water by combining three parts of 

 arsenate of soda with seven parts of acetate of lead, the chemical 

 action which results pi'oducing arsenate of lead. The poison may 

 then be mixed with water in the proportion required. This insecti- 

 cide, when mixed with water in the proper proportions, is applied 

 in the form of a spray in the same manner as Paris green. 



In using any of the above insecticides for the cottonwood leaf 

 beetle, the first application should be made when the ueetles first 

 appear in the spring. This should be followed by one or two other 

 applications as the occasion demands. 



Catching and killing the beetles and la/rvcB has proved a success- 

 ful method of combating this insect at Liverpool, N. Y. The 

 insects are caught by means of a machine, as shown in Plate II. 

 The oi'iginal, of which the photographs for these plates were taken, 

 was made by Mr. Joseph Kennedy of Liverpool. The dimensions 

 of the body are as follows : Length, 5 feet ; width at the rear end, 

 2 fe(it; front end, 20 inches; depth, 6 inches. The body thus 

 forms a shallow tank, which may be lined with tin or zinc, and in 

 which kerosene oil should be kept while the machine is in use. A 

 number of narrow strips are placed longitudinally over the top i* 

 the manner shown in Plate II, to keep the willows from touching 

 the oil. Stout runners fastened to the underside support the 

 machine. 



Plate III shows the machine in position ready for use. As it will 

 be observed it is made to run between the rows. The long arms which 

 extend obliquely from either side, cause the willows to bend over 



