THE NATIONAL NURSERYMAN 
217 
SOME IMPORTANT ENEMIES OF NURSERY AND 
ORCHARD 
The Peach Tree Borer 
By JOHN B. SMITH, New Jersey 
In bulletin 235 of the New Jersey Agricultural Experi¬ 
ment Stations, Dr. Smith devotes about eight~pages to a 
consideration of the peach tree borer, of which the follow¬ 
ing is an abstract. 
As the shining blue moth which is the parent of the peach 
tree borer is seldom seen by the orchardist, the form which 
is most'familiar is the white grub-like caterpillar which may 
be seen at any time during the summer or early fall. The 
largest of these, from an inch to an inch and a half in length, 
appear in early summer. The borer gets its living just 
beneath the bark of the tree at the crown, and a mass of 
gum on the bark is the telltale sign which indicates the 
presence of borers. 
When the eggs—of which an individual moth sometimes 
lays five or six hundred—hatch, the borers are scarcely one- 
sixteenth of an inch long. It is thought that not ten per 
cent of these borers live long enoughvto enter the tree, and 
this is doubly fortunate, as there seem to be practically no 
natural enemies of the borer. The borer never transforms 
into an adult the first season, and the grubs in the second, 
third, and fourth stages lie dormant during the winter. 
None of the caterpillars mature till late June, and the life 
of each moth is but a few days. However, the process of 
transformation keeps up all during the summer. 
While trees are not always killed when infested by 
borers, their vitality is lowered, so that they become liable 
to some other attack, and furthermore they do not produce 
the amount of fruit which might otherwise be expected. 
The borers are found in New Jersey wherever peach trees 
grow, and they attack cherry and plum to some extent. 
No insecticide application is known which is certain to 
exterminate these borers. Frequent applications of hot 
water not over 175 degrees will sometimes free the trees of 
them, when present in small numbers, if the gum is first 
removed. What is needed is a careful examination of the 
trees twice a year, late in the fall and in May or early June, 
removing all gum, and cutting into cavities to find and 
destroy borers. Dr. Smith has the following to say in 
regard to spraying directly after the spring examination, 
in order to prevent any young larvae getting into the trees 
later: 
{Continued on page 2jo) 
Bear Pit and Lake, Fair Grounds Park, St. Louis. 
