110 DECIDUOUS FKUIT INSECTS AND INSECTICIDES. 



between the nodes. Smaller rusty scars or pits are often found under 

 the buds occupied by the mites and undoubtedly result from the 

 puncturing of the tender tissue. 



The mite infests both seedlings and budded trees and is also com- 

 mon in orchards. The injury to seedlings, which as a rule are budded, 

 below the point from which the laterals in most cases develop, is 

 much less important than the injury to the budded stock the season 

 following. Injury in orchards has not thus far been observed to be 

 serious, but the mites are usually common and might be readily 

 introduced in nurseries with budding-wood. 



HABITS AND NATURAL HISTORY. 



But few observations have been made on the habits of the peach 

 bud mite and further information is very desirable for a proper appli- 

 cation of control measures. According to Prof. Waite, as detailed to 

 the writer in conversation, the mites hibernate on the plants behind 

 the bud scales. It is especially important to know if the mite winters 

 exclusively on the dormant nursery trees and if it has other important 

 food plants than the peach. The writer examined in March, 1906, 

 a lot of dormant peach stock from an infested nursery, including 

 several trees badly injured, and only one mite was found hidden in a 

 small cavity in the stem near the base of the tree. December 15, 

 1911, a lot of 36 1-year peach trees badly injured by the mite were 

 carefully examined, and while two specimens of a gamasid mite 

 were found, no specimens of the peach bud mite were discovered. 



The mites appear on the trees quite early in the spring, and by 

 the time the shoots are 18 or 20 inches in height, their injury is much 

 in evidence. As stated by Mr. Phillips for tidewater Virginia, the 

 injury has begun to show plainly by May 17, at which time 10 to 20 

 per cent of the trees already showed more or less symptoms of attack. 

 Mr. Phillips believed that the injury began as early as May 12, and 

 presents a table showing the proportion of trees injured at different 

 heights from the ground, as already quoted (p. 107). In a Delaware 

 nursery, injury was very common by June 6, the attack beginning 

 apparently two or three weeks earlier. Dr. Smith, speaking of 

 thrips injury in New Jersey, states that it was quite common by 

 June 8, at which date almost 50 per cent of the shoots in nurseries 

 examined had the terminals killed. It is evident, therefore, that the 

 mite begins operations during the latter part of May. Mr. Phillips's 

 observations indicate three different periods of principal injury, 

 which he considers mark as many generations of the mite. 



Breeding probably occurs largely on the trees. Mr. Johnson records 

 finding eggs of the mite in cavities behind the injured buds. The 

 writer on different occasions has found the mites of various sizes 

 behind buds, indicating that they had there developed. 



