66 NEW YORK STATE MUSEUM 



Kerosene emulsion. One tree was painted with an undiluted 

 stock kerosene emulsion July 25th. An examination on October 

 5th showed very little penetration of the bark in the vicinity of the 

 galleries and no living insects were to be found in the burrows 

 started prior to the treatment. Some beetles were entering the 

 bark at the time of our examination and were evidently not de- 

 terred therefrom by the earlier application. 



A 50 per cent kerosene emulsion was sprayed upon another tree 

 the same date, and observation on August 5th showed that the in- 

 sects were destroyed in the burrows and that there was also some 

 penetration of the adjacent tissues. The outer bark did not seem 

 to be affected in the least. 



Scalecide. A 20 per cent solution of this proprietary compound 

 was applied to infested trees September 7th and an examination 

 on October 1st showed living grubs in four out of five burrows. 

 In one case the larvae had made their way to a distance of two 

 inches from the gallery made by the female. This had a thicker 

 bark than the one treated with Barcurol or carbolic acid and the 

 comparison was therefore not exactly fair. It is likewise probable 

 that the treatment was made too late in the season to give the best 

 results, since the grubs were evidently some distance from the 

 female gallery and therefore mostly out of reach of the application. 



Carbolic acid. This was prepared by diluting a gallon of soft 

 soap with an equal amount of hot water and stirring therein a pint 

 of crude carbolic acid (y 2 pint refined), allowing it to set over 

 night and then adding 8 gallons of soft water. This solution was 

 applied to trees on September 7th, and examination on October 

 1st showed discolored areas on each side of the main gallery for 

 a distance of about three-quarters to one and one-quarter inches. 

 There were very few or no grubs found alive and the adjacent 

 tissues were healthy and apparently uninjured. This treatment 

 was made to a thinner barked tree than the one treated with scale- 

 cide and the grubs were therefore somewhat more accessible. 



Black leaf 40. A few trees were treated with this material used 

 at the rate of 1 to 200 and adding thereto 3 pounds of soap to each 

 50 gallons of water. The trees were sprayed September 7th. An 

 examination on October 1st showed the presence of some living 

 larvae under the rather thick bark. This treatment, as in the case 

 of others given at this date, was too late for us to expect the best 

 results, and in this particular instance was limited to trees with a 

 thick bark, the latter rendering the penetration by the insecticide 

 more difficult. 



