EXPERIMENTS WITH WINTER WASHES AGAINST THE SAN JOSE 

 SCALE, SEASON OF 1894-95. 



By C. L. ISIarlatt. 



A preliminary re|)ort on the winter treatment of tlie San Jose scale, 

 as conducted by the Division of Entomology, was given by Mr. How- 

 ard in a paper on this insect in the last number of Insect Life 

 (pp. 293, 294). Additional experiments have since been made, and 

 later notes made on the older ones, and the following detailed record of 

 experiments and summary of results, with deductions bas'^d on them, 

 may be considered supplementary to the report referred to. The num- 

 bers of the ex])eriments in this article fillow the actual order of their 

 application, and do not correspond M'ith the numbering in the first 

 report, but they are similarly classified, and no difficulty will be experi- 

 enced in referring from one to the other 



GENERAL NOTES. 



Hinforif and condition of trees treated. — All the experiments were con- 

 ducted in the orchard of Mr. E. Dows, near Riverside, Md. The 

 orchard is chiefly of i)each, with some apple trees intermixed, and origi- 

 nally contained about 2,000 peach and 250 apple trees. A portion of 

 the apple and peach stock was obtained from the Lovett Nurseries and 

 planted in 1888. This was the source of infestation. The greater por- 

 tion of the orchard was, however, obtained from a Yirgiuia nursery 

 in 1891, and was infested by the gradual spread of the scale from the 

 Lovett stock. Experiments were conducted on both lots of trees, but 

 for the most part on trees of or adjoining the original Lovett stock. 

 The trees treated were all heavily infested with the scale, the worst 

 infested trees being selected ; and from this fact, as will be noted later, 

 the death of certain trees, or portions of them, subsequent to treat- 

 ment, is due, with two or three exceptions, rather than to the effect of 

 the washes. 



Bates of, and conditions foUoicing treatment. — The applications were 

 made at four different times, as follows: 



The first series was made on October 25 and 2G, 1894, and comprised 

 experiments 1 to 5. The trees at this time were still in leaf, but the 

 foliage was mature and ready to fall. 



The second series was made November 17, and included experiments 

 <) to 9. Subsequent to these applications (series 1 and 2) the weather 

 conditions were very favorable, no rains occurring for some da3^s, and 

 in fact the mouths of October and November, 1894, were exception- 

 ally dry. 



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