38 SOME INSECTS INJURIOUS TO FORESTS. 



insecticide value itself, but because the emulsion made with it is more permanent, 

 and does not lo^-e its creamy consistency, and is always easily diluted, whereas 

 with most of the other common soaps the mixture becomes cheesy after a few days 

 and needs reheating to mix with water. Soft soap answers very well, and 1 quart 

 of it may be taken in lieu of the hard soaps. 



In limestone regions, or where the water is very hard, some of the soap will com- 

 bine with the lime or magnesia in the water and more or less of the oil will Ije 

 freed, especially when the emulsion is diluted. Before use, such water should be 

 broken with lye, or rain water employed. * * * 



For use on locust trees dilute 1 gallon of emulsion with 2 gallons of 

 soft water. 



Pure kerosene and pure petroleum will effectually kill the insects, 

 but may do some damage to the bark of the trees. 



Experiments with carbolic emulsion indicate that this preparation is 

 of no value to kill the young larvte. 



POISON BAIT. 



Experiments showed that the beetles would feed readily on poisoned 

 bait, such as sugar, sirup, or molasses with some arsenical mixed in, 

 when this was smeared on the trees. Such baits are fatal to the 

 beetles, but the danger of killing honeybees is so great that their use 

 is not recommended in localities where honeybees are kept. 



DAMAGE TO CUT WOOD AND DANGER OF INTRODUCING THE INSECT INTO 



NEW LOCALITIES. 



We have determined that after the borers have once entered the 

 wood they may complete their development in the cut and dry 

 branches; they will evidently do so, therefore, in posts or other 

 material manufactured from trees cut between the 1st of May and the 

 middle of September; from this it is plain that locust should not 

 be cut during this period for an}^ purpose except to destroy the 

 borers, or, if it should be necessary to cut it, the tops should be burned 

 and the logs submerged in ponds or streams for a few days before 

 they are shipped or manufactured. This is very important, both to 

 prevent damage to the manufactured material and the introduction of 

 the insect into the far West and other sections of the country which 

 are at present free from it. 



SELECTION OF LOCATIONS VOll EXTENSIVE PLANTINGS. 



The fact that there are many sections and localities of greater or 

 less extent within the natural home of the locust and its insect enemies 

 where, from some unknown cause, the tree grows to large size and 

 old age without perceptible injury from borers and other insects, sug- 

 gests the importance of selecting such localities for any proposed 

 extensive operations in the line of artificial planting, or utilization of 



