164 Report of State Board of Horticulture. 



cent of these dead on the third day and ninety-three per cent on the 

 seventh; the average final effect of the insecticide, the destruction of 

 ninety-three per cent of the scales. Comparison "with No. 1 — similarly 

 treated except that the California wash was used — shows a difference of 

 fourteen per cent of the scales finally killed, in favor of the Oregon wash. 



Tree No. 12. — A fifteen-foot tree, with an eight-inch trunk and a twelve- 

 foot top; in fair condition, moderately infested with the scale. Sprayed 

 but once, with fifteen gallons of water, on the day following the insecti- 

 cide treatment. Sixty-six per cent of the scales alive in the beginning; 

 eighty-five per cent of these dead by the third day; ninety-three per cent 

 by the seventh, and ninety-six per cent by the sample, on the twelfth; the 

 average final effect, the destruction of ninety-five per cent. Comparison 

 with No. 2, the corresponding specimen of Lot 1, gives a difference in 

 favor of tlie Oregon wash amounting to five per cent of scales finally 

 killed. 



Tree No. 13. — A twelve-foot tree, with a six-inch trunk and a thirteen- 

 foot top; in good condition, and but moderately infested. Sprayed with 

 water three times, beginning March 6, with intervals of one day between 

 applications, the first rainfall coming between the first and second 

 sprayings. Fifty-seven per cent of the scales alive in the beginning; 

 eighty-nine per cent of these dead on the seventh day, when the first 

 subsequent count was made, and ninety-four per cent on the twelfth; 

 general average effect, the destruction of ninety-four per cent. On the 

 companion tree, No. 3 of the first lot, an average final destruction of 

 seventy-eight per cent, making a difference of sixteen per cent in favor 

 of the Oregon wash. 



Tree No. 14. — This tree was thirteen feet high, with a six-inch trunk 

 and a sixteen-foot top. It was in good condition but badly infested by 

 the scale. It was treated but once with water, thirty gallons being 

 applied seven days after the insecticide, agreeing in this respect with No. 

 6 of Lot 1. Forty-nine per cent of the scales were alive in the begin- 

 ning. Eighty-three per cent of these had been killed by the fifth day, and, 

 according to the sample count made, ninety-six per cent by the seventh 

 day. Owing, however, to a low ratio in the hundred-scales count on the 

 twentieth day, the final effect stands at ninety-two per cent of the scales- 

 destroyed. The corresponding ratio for No. 6 was eighty-six per cent— 

 a difference of six per cent, in this case, in favor of the Oregon wash. 



Tree No. 15. A thirteen-foot tree, with a six-inch trunk and an eigh- 

 teen-foot top; in fair condition, but badly infested by the scale. This 

 tree received no treatment with water until March 17, when fifteen gallons 

 were applied — fourteen days after the application of the insecticide. 

 Tree No. 8 of Lot 1 is the companion tree. Sixty-one per cent of the 

 scales on No. 15 were alive in the beginning; eighty-seven per cent of 

 these were dead on the fifth day; and the final average stands at eighty- 

 nine per cent. This agrees practically with the average for No. 8, which 

 was eighty-eight per cent. 



