i:-^2 



Slingerland, made in the most important article on this insect which 

 has hitherto been published* 



Discussing- the methods of its spread he says that "the borer 

 probably never leaves the tree upon which it is hatched from the 

 eg-g- laid on the bark, but spends nearly eleven months of its yearly 

 life cycle on or in the tree. It can thus be easily transported for 

 long- distances on infested trees, and this is doubtless the way in 

 which it usually reaches new localities. In the spring and fall, 

 when the trees are usually transported, many of the borers are 

 quite small and easily escape casual observation. As large peach- 

 trees are rarely moved, the growers of nursery stock are most re- 

 sponsible for the introduction of the insect into new localities.'" 



It has been found in the roots of the smallest stock taken from 

 the nursery, and has been noticed on many nursery trees shipped 

 from one state to another, both in the eastern states and in Cali- 

 fornia. Mr. V. H. Lowe, of the Geneva Experiment Station, said 

 in 1897 that it was a common thing- to find many young- peach- 

 trees in the packing--shed, waiting- to be shipped, which were 

 infested by borers; and Sling-erland adds, "It is doubtful if there 

 is a peach nursery lo-day east of the Rocky Mountains that is not 

 more or less infested with the peach-tree borer. It is one of the 

 most serious of the insect pests that are now being- sent out by 

 nurserymen. When it once g-ets a foothold in an orchard or local- 

 ity it may slowly spread from orchard to orchard by the movements 

 of the adult insects or moths which fly readily but apparently not 

 for very long- distances. Peach- plum- prune- apricot- or cherry- 

 trees from a nursery should always be carefully examined for borers 

 before seiting- them, especially as young- trees are often killed by 

 g-irdling- just beneath the bark under g-round. Indeed every borer 

 weakens the tree more or less, the damage done depending^ much 

 on the age of the tree and the kind of care it has received." 



In the Illinois nursery inspection of 1900 these borers were 

 noticed in thirty-seven nurseries out of eig-hty in which peach stock 

 is specially mentioned. Remembering- the fact that these nursery 

 trees were insjiected while standing in the rows, and that the 

 occurence of small borers was doubtless often passed without 

 detection, we are safe in saying: that over half the nurseries g-row- 

 ing peaches are more or less infested by this borer. The cases 

 reported were not by any means limited to the oldest trees, but 

 included seedlings, yearlings, and two-year-olds, and also trees in 

 the packing--shed ready for shipment. The ratio of injured trees 



*Bulletin 176, Cornell I'liix ersity Agricultural Experiment Station, Decem- 

 ber, 1899. 



