THE PEACH BUD MITE. 107 
Data in regard to height at which injury occurred on the trees. 
| 
Number Number Number | 
Number of injured injured injured 
hiked Number | Within 94 | between 23 58 oe 
Re ee uninjured. 2 | and 4 feet : 
row. feet of the Bpowelthe 4 feet from 
ground. od ground. 
g : 
182 25 25 41 21 
43 9 5 17D P| (Sere Seeeree 
119 64 9 34 12 
161 109 6 26 20 
225 180 13 24 8 
194 123 9 39 23 
176 94 14 39 29 
1 Tn this case no distinction was made between those injured at this height and those injured at above 
4 feet from the ground. 
When the writer examined the nursery, on May 17, quite a number of the trees 
had already been injured, and the indications are that it began about May 12. The in- 
jury occurred at an almost uniform height on the trees for three periods: First, from 1 
to 2 feet high, about May 12; second, from 24 to 34 feet high, about June 12; third, 
about 4 feet high. The percentage of trees injured increased with each period, indi- 
cating that there must have been several successive broods of the form causing the 
trouble. 
The dividing line between the number injured at 24 to 4 and above 4 feet was not 
gauged properly in the latter part of the table; hence the figures in the first line should 
be considered as much more nearly correct than the others. 
Occasional complaints concerning this ‘‘stop-back”’ disease have 
been received by the Bureau of Entomology during the past several 
years. Specimens of injured peach trees from a nursery company near 
York, Pa., were received in 1905, and the damage done was stated to 
be heavy. During the spring of 1906 a Delaware nurseryman com- 
plained of serious loss to peach stock, estimating for the previous 
season a loss of about $2,000. The writer visited this nursery in 
June of the above year, and found the trouble quite prevalent, 
though, as stated by the owner, not so serious as the year before. In 
a large nursery in Maryland during the same year the work of the 
mite was in evidence, occurring quite generally over a large block of 
budded trees, though not especially serious. 
Complaint of this affection in a large nursery near Philadelphia 
was received July 27, 1911, through Prof. H. R. Fulton, State 
College, Pa., with specimens of injured plants. It was stated that 
there had been a considerable amount of the trouble that year as well 
as a slight amount the year previous. Mr. J. F. Zimmer, of the 
writer’s office force, visited this nursery August 24-25, and in con- 
ference with the owners it was learned that the injury during the 
year 1911 was estimated at about $15,000. This nursery was later 
visited by the writer and the injury was found to be quite serious, as 
stated, involving a portion of the large block of budded trees, 
and a small area of injured trees was found in a seedling block. The 
mite was found in some numbers working on peach, and a few 
