6 

 the stem lengthwise in both directions from the frass-elogged hole and bending 

 back the cut portion will usually i-eveal the borer, which can then be removed 

 and killed. If the stem is subsequently covered with earth, the operation will 

 have little injurious effect upon the plant. By constant watchfulness from the 

 middle of July to the first of September, a few plants in a home garden can 

 be protected from excessive borer injury by this means. 



The Use of Insecticides. 

 Certain insecticides have been tried in the past against the squash vine borer, 

 and have been declared valueless. Among these were arsenate of lead painted 

 thickly on the squash stems, and wrappings of tarred paper. Injections of 

 various toxic substances have been tried at this station, but without success, both 

 because of the nature of the burrows and of the webbing of silk and frass which 

 obstructs them. Studies of the life history and habits of the species in 1920 led 

 to spraying experiments in 1921 with the following materials : — 



Material. Possible Action. 



Arsenate of lead powdei", 3 pounds in Poisoning of newly-hatched larvae. 



50 gals, water. 

 Nicotine sulfate (Black-leaf "40"), 1 



part in 100 parts of water. 

 Bordeaux mixture, 4-1-50 formula. 



Penetration and killing of the eggs 



repelling of adult moths. 

 Repelling of adults. 



Preliminary experiments with these materials were conducted in 1921 and 

 1922 leading up to the sitccessful field applications of 1923. On the basis of 

 this work, the following sprays were applied in 1923 : — 



Material. 



Action of Spray. 

 Toxic to eggs. 



Poisons newly-hatched larvae as they 

 chew at surface of squash plant. 



Black-leaf "40", 1-100, 1-250, and 



1-500. 

 Arsenate of lead powder, 2 pounds in 



50 gals, water; 3 pounds in 50 gals. 



water, plus " Kayso " sticker. 



The work was done on a commercial scale at Littleton, in cooperation with a 

 squash grower, and at the Agricultui'al Experiment Station at Amherst. It 

 is here reported in some detail. 



The Littleton Experiment. — Mr. Homer Richards, a truck gardener and 

 orchardist living in Littleton, offered the use of a one-acre field of ^nnter 

 squashes and, in addition, his assistance in the application of the sprays. The 

 field contained twenty rows planted fifteen feet apart, and twenty-five hills 

 six feet apart in each row. Plots were marked off as follows : — 



Bows. Treatment. Kows. Treatment. 



Four applications were made : on July 5, July 12. 

 July 19, and July 26. Compressed air sj^rayers of 

 three gallon capacity were used for the first three 

 applications. Each was fitted with a short spray rod 

 and a 45° angle disc nozzle, pictured in figure 1. 

 All portions of the plants were thoroughly sprayed, 

 particular attention being paid to the base of the 

 stem. The fourth application was made with a power 

 sprayer and one lead of hose bearing the short spray 

 rod and angle nozzle. A pressure of 100 to 125 

 pounds per square inch was maintained. 



Examinations to check the progress of the infesta- 

 tion and the effect of the treatment were made by 

 the writer on each trip to Littleton. On July 13, a 



count of eggs on about twenty-five plants in each treatment gave the following 



results : — 



Fig. 1. — 45° Angle-disc Nozzle 

 Used in the Experiments. 



I 



