REPORT OF THE STATE ENTOMOLOGIST If) 1 2 6j 



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 tgg 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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