108 DECIDUOUS FRUIT INSECTS AXD INSECTICIDES. 



examples were noted by Mr. Ziminer on an adjoining block of apple 

 of the Jersey Sweet and Early Harvest varieties. The varieties of 

 peach most injured were Crawford's Late, Mountain Rose, and 

 Old Mixon. The varieties Crosby, Stump the World, and Georgia 

 Bell were least injured. The ground planted had been in wheat in 

 1909 and was planted to peach for the first time in the spring of 

 1910. The buds used were obtained partly from a bearing orchard, 

 but largely from nursery trees in an adjacent block, but in which no 

 injury had been noted. 



A similar outbreak was also reported as occurring in a near-by 



nursery- 



A prominent nursery company in Ohio, writing of this trouble, 



states, under date of October 30, 1911: 



We have been bothered with the thrips in peach trees for 15 or 20 years. This year 

 and last very bad. Some years very little. This year first time ever bothered much on 

 peach seedlings. If we can get peach buds 3 or 4 feet before this pest begins, we can 

 make very good trees. 



A Maryland nursery firm gives their experience as follows, under 

 date of October 24, 1911: 



We have had lots of trouble and loss caused by the ' 'setback " on peach seedlings and 

 also on peach buds. In 1910 we saw no signs of it, but this year (1911) it caused us a good 

 deal of extra expense. When the trees are stung by this insect in the terminal bud 

 during the summer and when the trees are about 18 to 24 inches tall, it causes them to 

 stop growing in the top and put out a lot of side or lateral branches, and if not attended 

 to they will be worthless. The past summer we kept a gang of men going over our 

 peach blocks and cutting or heading in the side branches in order to throw the growth 

 to the terminal and make them start a second growth. In this way by constant work 

 we got our trees to start to grow and the most of them finally outgrew the trouble. We 

 knew no other remedy than to cut the side branches back 2 or 3 inches. We notice it 

 is much worse in some places even in the same field than others. 



Prof. Wake's careful observations, and those of Messrs. Johnson, 

 Phillips, and others, indicate clearly that the Tarsonemus waitei is 

 the cause of the so-called " stop-back" affection of peach nursery 

 stock. It may also be true that injury practically identical in effect 

 on the trees is caused by thrips, as stated by Dr. Smith and Prof. 

 Alwood. Young thrips larva?, principally Euthrips tritiei, are very 

 commonly found in the tender growing tips of various kinds of 

 vegetation, and are especially common in peach nursery trees. In 

 blocks of trees infested with the mite, the thrips larva? have been 

 found by the writer in great abundance, but never, so far as could be 

 determined, killing the tips of the shoots. The writer is inclined to 

 the belief that the injury in Ohio, Xew Jersey, and Virginia (as shown 

 by Phillips) is due to the Tarsonemus, its small size, agility, and 

 habits contributing to its oversight. 



Am T injury to the growing tip of a peach shoot, as by plant-bugs, 

 would naturally produce a similar effect in causing the cessation of 

 growth and the development of lateral shoots, but the comparative 



