REPORT OF THE ENTOMOLOGIST. 557 



1^ gallons of water, and this proved fatal to about one-half of the eggs. As this is 

 out of all proportion as compared with the other experiments made by spraying the 

 egg-masses upon the trees with the tobacco decoction of various strengths, I am led 

 to believe that when the egg-masses are simply immersed in any solution, except 

 when held in the solution for some time, they do not become so thoroughly saturated 

 with it as when the latter is sprayed upon them; and I have proved beyond a doubt 

 that a solution thrown upon the insects in the form of a fine spray will liave a bettiir 

 effect than if thrown upon them in a coarser spray, just as a heavy fog or ruist will 

 more thoroughly wet a tree than a heavy shower of ram in large drops will do. 



The cost of the tobacco at wholesale is about 10 cents per pound, but sometimes 

 refuse tobacco can be obtained from cigar manufactories at from 14 to 2 cents per 

 pound. 



SHEEP DIP. 



This was the " Gold-leaf" brand, manufactured at Louisville, Ky., and said to be 

 a pure extract of tobacco; it costs about $1.75 per gallon when purchased in large 

 quantities. 



It was diluted with water in varioiis proportions, but even when used in the pro- 

 portion of 1 gallon of the dip to 30 gallons of water it proved fatal to only about four- 

 fifths of the young insects and one-fourth of the adult females with egg-masses, 

 while the eggs were scarcely affected by it. 



Several egg-masses were immersed in the pure dip, and none of the eggs thus 

 treated hatched out. 



TOBACCO SOAP. 



Samples of this soap were received from the manufacturers, the Rose Manufactur- 

 ing Company, of 17 South WiUiam street. New York City. The soap was first dis- 

 solved in hot water and afterward diluted with cold water. 



One Pound of the Soap to nine Gallons of Water. — This proved fatal alike to the 

 insects in all stages of development and also to their eggs. 



One Pound of the Soap to twenty-one Gallons of Water. — This was fatal to all of 

 the insects with the exception of about one-third of the adult females before secret- 

 ing the egg-masses and a slightly larger number of those with egg-masses. 



The cost of this soap has heretofore been 50 cents per pound, but I am informed 

 by the agent here, Mr. J. B. Francisco, that the price of the soap has been recently 

 reduced one-half. 



VINEGAE. 



A small branch of a lemon tree upon which were a number of Cottony Cushion- 

 scales was immersed in pure grape vinegar, but it had very little effect upon the 

 adult females and their eggs, and produced no perceptible mjuiy to the leaves. It 

 likewise had but little effect upon the insects when used in the proportion of 1 gal- 

 lon of vmegar to 8 gallons of water in which 4 pints of soft soap had been dissolved. 



PAEIS GREEN. 



One-half an Ounce of Paris green was thoroughly stirred into ttvo Gallons of 

 Water. — The whole was sprayed upon a small orange tree growing in the shade of some 

 large eucalyptus trees. This proved alike fatal to the insects and the tree. In many 

 places upon the ti-ee the sap had exuded from the bark in considerable quantities, 

 and remained adhering to the bai-k in the form of a brownish gum. 



One-third of an Ounce of Paris green to two Gallons of Wafer.— This was sprayed 

 upon all parts of a small orange tree, the greater part of it being sprayed upon "the 

 trunk and bases of the larger branches. In these places all of the insects were kiUed, 

 but fully one-tliird of those situated upon the outer ends of the branches were not 

 killed. In several different places the sap had exuded from some of the branches. 



One-fourth of an Ounce of Paris green to tico Gallons of Water. — This also killed all 

 of the insects upon the trunk and bases of the larger branches, where the greater 

 part of the solution had been sprayed, but only about one-half of the insects situated 

 upon the outer ends of the brandies were killed. This solution did not cause the 

 sap to exude from any part of the tree. 



One-fourth of an Ounce of Paris green to tico Gallons of Water and one Pint of the 

 Kerosene Emulsion. — The emulsion was formed by emulsifying 2 gallons of kerosene 

 in 1 gallon of hot water in which had been dissolved half a pound of soap. A pint of 

 this emulsion was diluted with 2 gallons of water, after which the Paris green was 

 added; but it was impossible to keep the green incorporated in the solution, as it 

 would rise to the surface the moment the stirring ceased. The effect of the solution 

 upon the tree and insect was about the same as in the preceding experiment, with 

 the exception that only about one-third of the insects situated iipon the outer ends 

 of the branches were killed. 



