MAR 24 1901 
Vol. LIX. No. 2617. 
NEW YORK, MARCH 24, 1900. 
*1 PER YEAR. 
FIGHTING THE PEACH BORER. 
LIFE HISTORY OF THE INSECT. 
‘'Digging Out”, Washes, Tobacco, Mounding. 
How and from what source does the Peach borer origi¬ 
nate? What is the best way of removing the borers from 
the tree? At what time in the season and how many 
times should this be done, and the best preventive? I 
am in the habit of utilizing my coal ashes as far as they 
go by putting about three shovelfuls around each tree, 
and find in removing the borers that the trees 
dressed with ashes are practically free from 
the pest. Is it really a preventive. t. c. 
I.agrangeville, N. Y. 
There have been so many questions about 
the Peach borer that we condense some of 
the facts from an interesting bulletin by 
Prof. Slingerland, recently issued from the 
Cornell Experiment Station. Those who de- • 
sire more than this brief synopsis may send 
for the entire bulletin. The borer is first of 
all a peach pest; it also attacks cherry, 
plum, nectarines and apricots. Probably its 
original food plants were the wild plum and 
wild cherry. It is usually spread to new lo¬ 
calities on infested trees, and is frequently 
sent out by nurserymen When stock is ship¬ 
ped. The Peach borer’s life is a complicated 
one. In New York the moths emerge from 
the latter part of June until September. A 
few hours after emerging the female moths 
(se Fig. 66) lay their eggs on the bark of 
the tree trunks, from six to 18 inches above 
the ground. In a week or 10 days later the 
young borer hatches from the egg, and works 
its way into a crevice in the bark, and soon 
begins feeding on the inner layers. It con¬ 
tinues feeding, gradually enlarging 'its bur¬ 
row until Winter sets in; then it stops eat¬ 
ing and hibernates through the Winter, 
either in its burrow or on the bark near the 
surface of the soil. In the Spring, usually 
about May 1, In New York State, the insects 
wake up from their Winter sleep, and grow 
rapidly for a month or more; then they leave 
their burrows and spin their cocoons at the 
base of the tree. A few days after this 
cocoon is made, the borer emerges as a moth, 
in which state it remains for about three 
weeks. Thus, the life cycle is completed in 
a year, fully 10 months of which are spent as 
a borer in the tree. In Canada, the moths do 
not begin to appear until July, while in the 
South they may be seen in April or May. 
Most peach growers are familiar with the 
work of this dangerous insect. Fig. 69 shows 
the base of an infested peach tree with the 
gummy mass which surrounds it. When 
working in plum trees there is less of this 
gum to be seen, and therefore it is not so 
easy to detect the borer either in plum or 
prune trees. 
Knowing the life of the insect, it is easier 
to figlu it. It is only possible to make suc¬ 
cessful battle against it in the borer stage, 
or during the few days it spends in the 
cocoon before the moths emerge. Prof. Slin¬ 
gerland, at Cornell, started out to find some 
practical means of fighting this borer; 400 
trees were selected for the sole purpose of 
testing so-called remedies. Over 25 methods, 
most of which had been highly praised, were 
trieu, and the most that can be said is that 
the majority of these methods were proved 
worthless. The method of freezing the in¬ 
sects failed. The use of bisulphide of car¬ 
bon was not satisfactory, and while boiling 
water killed the borers, it was not practical 
on a large scale, and would probably injure the trees. 
The best method, after all, is the old-fashioned “dig¬ 
ging” method familiar to most peach growers. With 
a piece of bent wire the grower digs down into t'he 
hole, and fishes out the borer from his hiding place. 
This “digging out” is the only thoroughly successful 
and safe way of killing the borer. It takes time and 
work, and Prof. Slingerland has found that in con¬ 
nection with it, some application of a wash or other 
substance will be a very useful thing. The best time 
to dig out t'he borers is in June, or from June to 
September in northern peach-growing countries. 
Some people work on the theory that the borer 
cannot stand a bad smell. They recommend tansy, 
Red cedar, tobacco, carbolic acid and other sub¬ 
stances. These were all tried, and all failed except 
tobacco. It was found that where tobacco stems were 
laid around the base of the tree, over two-thirds of 
the borers were kept out. It is not known 
how the tobacco stems acted on the insect, 
but where they can be obtained cheaply, 
there seems no doubt about their effective¬ 
ness. Another old-fashioned method of 
mounding or heaping earth around the base 
of the tree was found to be successful, keep¬ 
ing out over half the borers. This in con¬ 
nection with digging out proved quite effec¬ 
tive. Paper protectors or bandages also kept 
out over one-half the borers. Fig. 70 shows 
how tar paper was fastened to the tree. 
This worked well, although Prof. Slinger¬ 
land says that ordinary newspapers would 
do just as well in situations where they 
could be held to the. tree in spite of wind and 
rain. Wooden boxes around the tree give 
little protection, and are too expensive. 
Wire cages have been recommended, but 
they give poor results. All sorts of washes 
have been suggested, but most of them 
failed. Whitewash containing carbolic acid 
and lye did not give good results; neither 
did whitewash, paint, Paris-green or glue. 
A wash made of hydraulic cement has been 
suggested, but this did not keep out the 
borers. Printers’ ink injured the trees. 
Pine tar kept out but a few borers, but gas 
tar proved the best application that was 
tested. Prof. Slingerland says that he ex¬ 
pected the gas tar would kill the trees, but 
he tried it three years in succession on young 
trees, and they remained as healthy and 
thrifty as any others. When the trees have 
become well established, after a year’s good 
growth, he thinks the gas tar can be used 
with fair success. But he says go slow, and 
test it carefully before using much of it. 
Some of the lime washes give fair results, 
and in connection with the digging-out 
method might help. 
Speaking of lime and soap washes, Prof. 
Slingerland says that neither of them has 
much effect upon the Peach oorer. The cli¬ 
matic conditions in New York are such that 
a lime wash will scale off, thus making it in¬ 
effective before the moths have stopped lay¬ 
ing their eggs. Farther south these washes 
are said to have given good results. This 
may be due to the fact that the climate is 
such that the wash remains during the dan¬ 
gerous period. Some persons have advocated 
the use of Paris-green in the wash. This 
seems to be due to a wrong theory. The 
little borer does not eat its way through the 
wash, and thus taste the poison. It hunts 
tor a small crack or crevice, and works its 
way in below the surface bark before it be¬ 
gins to eat. In most cases the wash is placed 
on the tree bark entirely. This habit of the 
borer will explain why most of these washes 
are net effective. It is very difficult to cover 
the bark of a peach tree so thoroughly that 
these tiny cracks or crevices will not be left 
open. Crude carbolic acid is used in some 
-1 washes on the theory that it is offensive to 
the borer. Prof. Slingerland says that his 
THE PEACH TREE BORER AT WORK. Fig. 67. 
