^0 MASSACHUSETTS HORTICULTURAL SOCIETY. 



■can with a spring bottom aud the liquid can be forced from it, 

 into the burrows without difficulty. I have used bisulphuret of 

 carbou in various forms for insect destruction since 1885. It is 

 most valuable in washes for scale insects also. Injecting bisul- 

 phuret of carbon into the burrows of insects is, I consider, one of 

 the most important discoveries I have made for the destruction of 

 wood-boring larva. In 1893 we spent three months collecting 

 and destroying the larvae of this insect, and last year showed the 

 valuable effect of this thorough work in the decreased number 

 working upon our trees. 



The next most troublesome species of insects to us is the 

 Tussock Moth {Orgyia leucostigma) . I see that you have the 

 same species abundant in your own city. For their destruction I 

 have resorted to four methods. First, by hand-picking and by 

 removing the cocoons with wire brushes. In this way barrels of 

 the egg-masses are collected and then destroyed. Second, by 

 jarring the larvae down with a pole so arranged that a blow from a 

 mallet on a projection at the larger end of the pole, will jar down 

 any that may be on that limb, for they are easily dislodged by the 

 concussion. Third, by poisoning the foliage with London purple, 

 which is quite effective, especially on trees that have not been 

 properly cleared from egg-masses during the winter. Fourth, by 

 spraying the trunks of large trees that are covered with cocoons, 

 with an emulsion of petroleum and crude carbolic acid. This 

 emulsion, put on with a stiff spray, will penetrate most of the 

 cocoons and destroy the pupiii or larvae within, and many of the 

 eggs that have been deposited on the outside of the cocoons. 

 This last method is only resorted to, when from want of proper 

 winter cleaning, the trees have been defoliated by these insects. 



For the Elm Beetle (Galeruca xanthomalcena) we try to follow 

 up preventive measures by spraying the trees with London purple, 

 as soon as we find the first groups of eggs. This is usually from 

 May 28 to June 6. This spraying is kept up at intervals of two 

 or three weeks, until autumn. Another method which we are 

 faithfully following is to kill all the pupae we can find at the base 

 of the tree or along walls and in any out of the way places. This, 

 I think, is of the greatest importance, and all pupne should be 

 destroyed as fast as they show themselves. An emulsion of 

 petroleum and carbolic acid is used, and this is sprayed into and 

 over all places where the larvae have crawled to pupate. 



