39 



On the whole, the treatment was far from satisfactory, and was not 

 sufficiently so to render the use of the wash profitable in comparison 

 with some of the other insecticides used against this species. 



Experiment II. — ^The test at Annapolis Junction was made on an 

 orchard of 225 ten-year-old apple trees and about 50 two-year-old peach 

 trees. There was a general sprinkling of the scale throughout the 

 orchard, and many trees were quite badly infested, the trunk and limbs 

 being mostly incrusted with scale. The wash as made up was iden- 

 tical with that used at College Park, but was cooked in a large iron 

 boiler instead of in a barrel by the use of steam. The wash was 

 applied with the same apparatus, and when finished the trees were 

 quite thickly and uniformly coated with the mixture. The treatment 

 was made on March 27 and 28, the weather being clear, with but little 

 wind. The following weather record as furnished me by Col. W. S. 

 Powell, on whose farm the work was conducted, is of interest in this 

 connection: 



March 29. Warm, with showers in afternoon. 



March 30. Showers in afternoon. 



March 31. Snow and rain; cold winds. 



April 1. Cold winds. 



April 2. Cold wmds. 



April 8. Fair. 



April 4. Light rain. 



April 5. Fair. 



April 6. Light rain. 



April 7. Cloudy. 



April 8. Driving rain all day. 



April 9. Light rain. 



April 10. Fair and cold. 



April 12. Fair. 



April 13. Fair and windy. 



April 14-28. Fair, with variable temperature. 



May 6. Fair, with variable temperature. 



May 7. Rain during night. 



May 8-12. Fair. 



May 13. Rain in afternoon. 



The weather record was not kept after May 13, as later than this it 

 wa.s not considered as having any bearing on the experiment. 



A careful examination of infested twigs from difl'erent trees on 

 May 10 led to the conclusion that a considerably higher percentage of 

 scale had been killed than a subsequent examination on June 13 

 proved to be the case. On this date many young scales were crawl- 

 ing, and very many live scales were exposed by scraping the infested 

 limbs with a knife. After an examination of many trees, both peach 

 and apple, the percentage of dead scale was placed at from 45 to 50. 



In considering the weather record for this test, it will be observed 

 that rain fell on the three days succeeding the application, and on 



