109 



brought into the laboratory were placed on dry paper, thoroly sprayed, 

 and transferred at once to dry paper bags in which they were left for 

 twenty-four hours at a temperature of about 65 degrees F. From the 

 following table it will be seen that the different brands of soap differed 

 quite remarkably in their apparent insecticide power, the home-made 

 lye soap as tested in seven experiments (88.6 percent killed) equaling 

 the solutions of Black Leaf 40, while Peosta soap, as tested in ten ex- 

 periments, killed about as many chinch-bugs as the best of our home- 

 made infusions of cigar clippings. The lowest ratio of chinch-bugs 

 killed was 40.8 percent as the average of eleven experiments with 

 Lenox soap. 



For large-scale operations the commercial extracts of tobacco, used 

 as already described, are undoubtedly to be preferred as the most ef- 

 fective and reliable ; but for emergency work soap solutions will serve 

 an excellent purpose. One hundred and sixty-seven experiments made 

 with fourteen brands of soap gave an average of 66 percent of the in- 

 sects killed by this means. 



Insecticide Tests of Soap Solutions made by W. P. Flint, at Springfield, 



DURING THE WINTER OF 1912- '13 



Brands of soap 



No. of 



experiments 



No. of Percentage of 

 chinch-bugs used chinch-bugs killed 



Home-made lye 



Grandpa 's Tar 



Rub-no-more 



7 



11 

 11 



8 

 17 



8 

 15 



9 

 17 



4 

 15 

 24 

 10 

 11 



70 

 110 

 110 

 143 

 230 

 109 

 157 

 100 

 132 



62 

 190 

 250 

 100 

 120 



88.6 

 77.3 

 73 6 



Swift's Borax 



73 4 



Pyles Pearline 



Brown 's Pine Tar 



Home-made Rosin 



German mottled 



Topsy Tar 



Fels Naphtha 



73.0 

 70.6 

 70.0 

 67.0 

 64.3 

 61 



Tvorv 



59 2 



American Family 



Peosta 



56.4 

 48 



Lenox 



40.8 





167 



1,883 



Av., 66.0 



As a test of the practical usefulness of the soap sprays applied to 

 entire fields of well-grown corn, an acre and a half of heavily infested 

 corn was treated at Plainview August 2, 1913, when the plants were 

 four to six feet high. Unfortunately the soap selected was one of the 

 brands whicli experiments had shown to be of rather low efficiency. 

 Twelve bars of American Family Soap, each weighing ten ounces, 

 were dissolved in forty gallons of hard water (3 ounces to the gallon), 

 and the solution w T as applied to the corn by means of a barrel pump 

 set on a drag and drawn by one horse between the rows. Two rows of 

 corn were sprayed at each round of the field, one man driving the 

 horse and working the pump, and another handling the Bordeaux noz- 



