182 IS. C. Entomological Society 



these burrows or that the lime sulphur had acted as a slf)W stomach 

 poison following larval feeding on surface. tissue. In the laboratory the 

 value of lime sulphur as a stomach insecticide gave both positive and 

 negative results. The caustic action would appear to be the main con- 

 trolling factor, but it was not as great as anticipated, judging from the 

 number of live larvae found a week after the applications in hibernacula 

 and in buds. A careful record made in sprayed and unsprayed plots 

 showed that no more than a 50% degree of Control had been effected; a 

 ratio from 8.1 to .3.8. 



On May 9th, at Kaleden, when 60%-709( of the apricot husks had 

 fallen and the fruit was three-quarters of an inch long, when the larvae 

 ^\•ere half to full-grown, an application of 2 gallons of concentrated lime 

 sulphur to 100 gallons of water, to which was added 2i/2 lbs. of lead 

 arsenate paste, the results proved that many larvae died from arsenical 

 poisoning. Here, again, only 509?: efficiency was apparent; a ratio being 

 obtained of 7.2 to 4.5. 



Owing to the extensive spraying campaign that was conducted in 

 1918, an opportunity offered itself to check the general results over a 

 large acreage of peaches and apricots. The notes taken presented them- 

 selves without comparison to control blocks, hence are only judged on 

 tlieir relative commercial value, supported by observations of larvae in 

 situ. 



It was felt that both sprays individually applied did not accomplish 

 more than 50% results, though the results obtained, suppoi-ted by the 

 natural larval mortality during winter and a certain natural loss in the 

 pupae during May, were commercial and pronounced satisfactory. Those 

 growers witli extra zeal who applied two sprays, one before and the 

 other after blossoming, obtained practically 100% results, for their* 

 orchards hardly yielded any worms at time of picking. This proved the 

 desirability of making two sprays in heavy infestation, the practicability 

 of rendering an orchard commercially clean in a single season, and lastly 

 that moths do not move on the wing from one orchard to another to any 

 appreciable extent. 



In 1919, further notes on spraying were obtained. It was shown 

 that a power machine, with a 200-gallon tank, actually carrying about 

 150 gallons, with a pressure of 250 lbs., using a "gun," one man and a 

 driver, would spray two acres of 9-year-old apricots in bud to a filling. 

 The trees were planted 170 to the acre, and about 15 trees were sprayed 

 in 15 minutes. 



A Pontiac machine, a favored lower powered macliine, used for hill- 

 side work, carrying a 120 Imperial gallon tank, handled 5 acres of 

 apricots a day during April. Two nozzle men and a driver were required, 

 and 150-175 lbs. pressure was employed. Both machines did excellent 

 work, the coating of lime sulphur being thorough. 



