THE PEACH BUD MITE. 



107 



Data in regard to height at which injury occurred on the trees. 



Number of 



trees in 



row. 



Number 

 uninjured. 



Number 



injured 



within 2i 



feet of the 



ground. 



Number 



injured 



between 2h 



and 4 feet 



above the 



ground. 



Number 



injured 



above 



4 feet from 



ground. 



182 

 43 

 119 

 161 

 225 

 194 

 176 



25 

 9 



64 

 109 

 180 

 123 



94 



25 

 5 

 9 

 6 



13 

 9 



14 



41 

 129 

 34 

 26 

 24 

 39 

 39 



21 



12 

 20 

 8 

 23 

 29 



1 In 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 2\ to 3| 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 2\ 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 u 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 



