PEACH INSECTS 



301 



ment of the laterals, which in turn liave their tips killed in a 

 similar way ; the result is that the tree takes on a })ushy form 

 (Fig. 257) instead of developing a long, straight upright. 

 Such trees cannot be sold as 

 first-class stock. The loss from 

 this trouble in one New York 

 nursery, amounted in a single 

 year to $15,000. 



The cause of peach stop-back 

 has been attributed to a species 

 of thrips (Euthrips tritici Fitch), 

 to the peach bud-mite {Tar- 

 sonemus waitei Banks) and to 

 the tarnished plant-bug {Lygus 

 pratensis Linnaeus). It is quite 

 certain that in New York, Vir- 

 ginia and Missouri, at least, the 

 latter is responsible for the in- 

 jury. 



The tarnished plant-bug is 

 discussed on page 375. In New 

 York the adults emerge from 

 hibernation in March or April 

 and pass through at least one 

 generation on various weeds be- 

 fore attacking the peach. The 

 last of June or first of July the 

 adults migrate into the blocks 

 of nursery stock, where they 

 puncture the terminal buds and 



injure them, as described above (Figs. 255 and 256). While 

 a few eggs are deposited in the tender tips or in the leaf 

 petioles, very few nymphs are found on peach, practically 

 all of the injury being done by the adults. After three or 



Fig. 257. — A peach nursery tree 

 on which the terminal buds have been 

 killed by the tarnished plant-bug, 

 a condition known as stop-back. 

 Leonard photo. 



