REPORT OF THE STATE ENTOMOLOGIST I912 67 
The above experiments, while by no means conclusive, give 
sufficient data to warrant a continuance of the work, particularly 
with a preparation of oil or carbolic acid for the purpose of de- 
stroying the beetles or the recently hatched grubs before they have 
had an opportunity to bore any distance from the egg chambers. 
This treatment, it should be stated, can be recommended only for 
specially valued trees on lawns or in parks. It is possible that a spray 
with a whale oil soap solution, a lime-sulphur wash or even a thick 
whitewash just before the beetles begin to enter the bark of the 
trunk would prove of considerable service in preventing attack 
and be nearly as effective as the treatments tested above. This 
problem can be settled only by further experimental work. 
Mr Henry Bird, of Rye, informs us that in his opinion the 
treatment of infested trees after oviposition seems feasible in cer- 
tain cases. He found that spraying with a strong whale oil soap 
solution just before the females began to enter the trees, seemed to 
drive away the insects and prevent infestation. This, he states, 
proved to be the case with one large tree which during the month 
of July, was infested by hundreds of beetles feeding upon the leaf 
petioles. He found spraying with arsenate of lead of no service 
and a similar report was received from Mr de Vyver, though the 
treatment by the latter was, in our opinion, too late to be of 
material service. Mr Bird found from experience that treatment 
of individual galleries was less laborious than he had supposed. 
He personally went over several trees between the 20th and 23d 
of August in an area where the insects were abundant, the 
trees being 40 feet high and having between 200 and 300 gal- 
leries in the bark. He used a small squirt can oiler and about 
a quart of gasolene to the tree, only enough being injected to 
destroy the females or the eggs. This treatment he found caused 
no appreciable injury to adjacent tissues. His work with this 
oil was limited to moderate sized trees a foot or more in diameter 
and some thirty-five years old. It would undoubtedly be more 
difficult to treat larger trees in this manner, though in the case of 
highly valued hickories one could hardly class this method as 
impractical. 
Preventive measures. It is well known that plants are more 
susceptible to the attack of various insects when in an unthrifty 
condition. It is probable that the excessive droughts and ex- 
tremely low winter temperatures of recent years have had an 
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