86 BULLETIN NO. 4, DIVISION OF' ENTOMOLOGY. 



A strong stream of water was tried and proved effective, but labor- 

 ious, and the insects falling to the ground were not killed. 



Experiments with solution of murvite, made under a microscope, 

 showed that in all cases where the solution came into actual contact 

 with the skin of the insect the bug was instantly killed. Acting upon 

 this and the knowledge gained by previous observation and experi- 

 ment, I tried the effect of a fine, solid stream issuing under pressure, 

 using a solution of murvite, one part, to water two hundred and fifty 

 parts. The results were excellent ; the solution being forced into the 

 colonies broke them up, and coming into contact with the insects killed 

 them, the method of working being one man at the pump, another to 

 guide the stream. The apparatus improvised being badly adapted to 

 the purpose is very awkward. The work, although about four times as 

 fast as with the bellows atomizer, is not adequate to the economical re- 

 quirements. This method has the merit of no loss by damage to fruit 

 or leaves by the material used; the waste, falling on the leaves and 

 branches, will exterminate both scale insects and rust mites, these 

 being plentiful, but neglected in the presence of the more pressing 

 necessity of saving the growing crop from destruction by the mealy bug. 



Business required my presence at home, so I was obliged to leave. 

 As I can do so, I will try to fit up an apparatus adapted to this work. 

 Having none of the insects here, or, as far as I know, nearer than the 

 ake, twenty miles distant, I cannot make any experiments at home as 

 I would like to do. 



At Micanopy I found several large trees dying slowly from some un- 

 seen cause. Some time ago I induced one person to dig under the lateral 

 roots and examine the tap root of a tree in a similar condition ; result, 

 bark of tap root not all rotten. I was not present to examine it. The 

 tree being large and yielding well, the owners generally prefer to take 

 the chance of recovery to any act that may expose the roots and increase 

 the damage; but the matter is important and statements are confused- 

 some say that a white worm causes it ; others, white ants; others, wood 

 lice. 1 have found trees damaged by each of them, but they differ from 

 the causes at Micanopy. I have heard of its being serious at other 

 places. 



Can you advise me of the best means of proceeding, what to look for ? 

 and how to look for it, so that if I have opportunity I may intelligently 

 search into the matter ?— 1 Jos. Voyle, Gainesville, Fla., June 12, 1883. 



[This disease of the larger trees is supposed by Mr. Hubbard and others 

 to be caused by the tap-root reaching water and decaying in consequence.] 



