February, ’18] 
PETERSON: PEACH TREE BORER 
53 
The lasting effect of nicotine resinate is shown in one experiment 
where on July 16 the lower portions of fifteen seven-year-old peach 
trees were sprayed with two and one-half gallons of nicotine resinate, 
1-100 (one gallon for six trees). Small pieces of bark were removed on 
July 23, July 30, August 4, August 13 and August 21 from the trees 
which only received one treatment, and placed in a clean test tube 
with a small amount of distilled water and shaken. After standing 
for about 30 minutes the solution was filtered and a few drops of sili- 
cotungstic acid solution were added to the clear filtrate. Immediately 
the solution became cloudy having the appearance of a white milky 
solution. Bits of bark removed from unsprayed check trees were also 
tested each time and in all cases the filtrate remained clear. The 
sprayed trees were tested again on September 21, but at this time there 
was no indication of nicotine. The above qualitative test for nicotine 
is recommended by Mr. V. I. Safro. (See, “How to Test for the 
Presence of Nicotine on Sprayed Plants/’ Journ. of Econ. Ent., 1917, 
vol. 10, pp. 459-461.) The above experiment shows a definite test for 
nicotine on the bark of peach trees five weeks after application of 
nicotine resinate, 1-100. It should also be noted that a number of 
heavy rains occurred between July 16 and August 21. 
Summary 
The results in the above experiments are largely negative, so far as 
they may help to develop a much needed control measure for the peach 
tree borer. In brief they show the improbability of developing a poison 
bait for the adult, the partial repellent effect of certain chemicals on 
the female while ovipositing and the partial destruction of eggs when 
certain substances are applied as a spray. A number of experiments 
have been started and are now in operation on the use of various chemi¬ 
cal and mechanical tree protectors but the evidence obtained thus far 
is insufficient to warrant a statement at this time. The author is of 
the opinion that the peach borer problem will be solved when some 
mechanical or chemical barrier is found which will kill the larva before 
it enters the tree or prevent it from getting into the tree. The develop¬ 
ment of any control measure along the line of killing the larva after it 
enters the tree is not advisable. 
President R. A. Cooley: Mr. Peterson’s interesting paper is 
before you for discussion. 
Secretary A. F. Burgess: I notice on the program that in Mr. 
Peterson’s summary he made note of the use of tree protectors. I 
wonder if he has any information on that subject that he didn’t give 
in his paper. 
