182 MAINE AGRICULTURAL EXPERIMENT STATION. I9OO. 



July 11, potatoes beginning to bloom, no slugs hatched yet, 

 sprayed ; July 21, sprayed ; July 24, practically no bugs, less than 

 on any other plants : July 27, sprayed; August 1. with the excep- 

 tion of three hills the north side of which was missed in spray- 

 ing, only two bugs were seen in the whole length (30 rods) of 

 4 rows; August 8, practically free from bugs; August 10, 

 sprayed, it began to sprinkle as this was being applied, only a 

 light shower, but did not clear off; August 14, no bugs. 



Boxal as an Insecticide. Boxal is a "concentrated Bordeaux 

 mixture, reenforced with copper hydrate for the prevention of 

 blight and sufficient arsenic for killing leaf-eating insects." The 

 arsenic is in the form of arsenate of lead. It was applied in 

 these experiments four times at the rate of 5 pounds, and in 

 another plot at the rate of 10 pounds of boxal to the acre. The 

 field notes are as follows : 



Rows 17-32, boxal at the rate of five pounds to the acre. July 

 11, potatoes just beginning to bloom, no slugs hatched yet, 

 sprayed ; July 21, sprayed ; July 24, bugs more numerous than on 

 rows 1-16 (Paris green) but no badly eaten plants; July 27, 

 sprayed; August 1, bugs less than on rows 1-16 (sprayed with 

 Paris green) ; August 8, a few bugs, about the same as on rows 

 1 to 16; August 10. sprayed: August 14, very few bugs, — none 

 except on here and there a plant. 



Rows 33 to 48. Boxal at the rate of 10 pounds to the acre. 

 July 11, potatoes just beginning to bloom, no slugs hatched yet, 

 sprayed; July 21, sprayed: July 24, bugs about the same as on 

 rows 1 to 16, no living bugs on eaten leaves ; July 2j. sprayed ; 

 August 1, very few bugs and then only on occasional hills, no 

 need of further spraying for bugs ; August 8, practically no bugs ; 

 August 10, sprayed ; August 14, no bugs. 



In this experiment spraying four times with boxal at the rate 

 of five pounds to the acre and three times at the rate of ten 

 pounds to the acre kept the bugs from doing any damage. The 

 larger application was the more effective. 



Disparene. Disparene is a paste of arsenate of lead and "con- 

 tains from 62 to 68 per cent of arsenate of lead." As previously 

 stated it was received too late to be used in the experiment. It 

 was however applied to a piece of 3 or 4 acres which had been 

 sprayed twice with Paris green without killing off the bugs as 



