440 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



ments seem to show that tar is the most effective of these, but even 

 its use gives only a small measure of protection. Many planters 

 simply painted the tar on the outside of the base of some of the leaves, 

 but this soon became dry and hard and of little value. As kerosene 

 was often added to the tar more or less damage to the tree often 

 resulted and, in some cases, when equal parts of kerosene and tar 

 were used, many trees were killed. As the kerosene adds little 

 or nothing to the repellant value of the tar and as it is not needed 

 for a thinner, there is no excuse for using it in this way. In experi- 

 menting with this material many young trees, ten to fifteen years 

 old, were thoroughly cleaned by cutting out all the dead leaves, 

 flower stems, etc., and then examining the tree carefully to see whether 

 any beetles were already in it. Sometimes it was necessary to cut 

 awaj^ some of the green leaves also before the beetles could be reached. 

 A rather stiff wire with a hook or barb on the end of it was often found 

 convenient for spearing the beetles and pulling them from their holes 

 when they were deep in the tree. If the tree was badly infested with 

 beetles it was often found necessary to remove nearly all of the old 

 leaves before it could be thoroughly cleaned. After the beetles were 

 removed all of the new-cut surfaces and the inner side of the base 

 of the leaves were painted with tar, particular care being taken to 

 treat thoroughly all of the holes and any open spaces where the beetles 

 might enter. Alternate trees cleaned in the same way, but not treated 

 with tar, and other trees from which few or none of the leaves were 

 cut, were left as checks. An examination forty days later showed 

 that the trees treated with the tar had fewer beetles in them than the 

 check trees had, but the fact that many of the tarred trees were at- 

 tacked by one or more beetles shows that this treatment offers only a 

 small measure of relief. 



Other trees were treated with lysol and some with lysol mixed 

 with the tar, but as many of the leaves, especially the young leaves, 

 were badl}^ injured it was found that this substance could not be used 

 for this purpose. 



Coarse beach sand was poured into the crowns of a few trees, care 

 being taken that plenty lodged at the bases of all of the leaves. 

 Still other trees were treated in the same way with very fine sharp sand. 

 When the trees were last examined only one had been attacked by 

 the beetles, but not enough time had elapsed to make the experiment 

 of any value. A little white arsenic was mixed with the sand in some 

 of the trees. When such a mixture touched the young leaves they 

 were usually more or less injured. 



A few trees were dusted thoroughly with white arsenic, others 

 with Paris green, still others were treated with these arsenicals mixed 



