APPENDICES. 



APPENDIX I. 



THE ME ALT BUG AT OEANGE LAKE, FLORIDA. 



[Extracted from a letter by Jos. Voyle, Gainesville, Fla., June 12, 1884. Reprinted 

 from Bulletin 4, Division of Entomology, U. S. Department of Agriculture, p. 85.] 



Having business near Orange Lake during the past week, I visited several orange 

 groves. I found all of the Florida varieties of Scale-insects in abundance. Oranges 

 are already rusty, and the Rust-mite in many places, on both leaves and fruit, in such 

 large numbers as to give a distinct coloration, distinguishable at a distance of ten 

 feet. 



But the most destructive insect, at present absorbing all the attention of the orange- 

 growers there, is the Mealy-bug, Dactylopiua destructor* This insect causes the fruit 

 to rot under the colonies. A favorite place of lodgment is at the stem, under the 

 calyx ; the result is, the fruit drops. 



I staid there three days to examine methods used and experiment in their destruc- 

 tion. 



The cotton y armor repels all watery solutions. 



The methods used are : spraying each separate colony with pure kerosene by means 

 of bellows atomizers; and mechanical action rubbing or pinching each separate 

 colony (by colony I mean the little clusters consisting of from ten to several hundred 

 individuals) ; this is done by the fingers. 



I examined the trees that had been treated with the kerosene spray and found both 

 the leaves and fruit spotted yellow. I was also informed that fruit saved in this way 

 two years ago was useless, having absorbed the odor of kerosene. The effective 

 progress made by the means used is trifling, in consideration of the work to be done. 

 I tried experiments with solutions of murvite sprayed on, but with no good result ; 

 then tried kerosene butter, using thick; milky solution of murvite, which combines 

 in exactly the same way as with cow's milk, and found that an effective emulsion 

 could thus be made. 



After using and watching the action of this for some time, I saw that the interior in- 

 sects of a dense mass were protected by the exterior ones ; further experiments were 

 made to meet this difficulty. By watching the men at work I saw that nearly every 

 infested orange was handled to turn all of its sides to the eye ; that wherever a large 

 colony found lodgment in a fork of twigs or in a depression of the bark they were 

 handled, also that the bunches of Spanish moss (Tillandsia) formed formidable breed- 

 ing places. All of these require force for their dislodgment. 



A strong stream of water was tried and proved effective, but laborious, and the in- 

 sects falling to the ground were not killed. 



Experiments with solution of murvite, made under a microsocope, 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 experiment, 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. 



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