INSECTS INJURIOUS TO THE ORANGE. 421 



Strong tobacco-water, heated to about 130° F., has also 

 been used with some success, more particularly on the young 

 broods. 



Judging from the results obtained in a course of experi- 

 ments lately conducted under direction of the Department 

 of Agriculture, Washington, kerosene oil in the form of 

 emulsion promises to be a valuable agent in destroying the 

 different species of bark-lice. An emulsion made in the 

 following manner has been found most efiScient. Take of 

 kerosene oil one gallon, cow's milk, sour or fresh, half a gallon, 

 emulsify by thorough and constant agitation until the com- 

 pound has the appearance of thin butter. Dilute one pint 

 of this creamy mixture with one and a half gallons of water, 

 adding the water gradually, and stirring constantly, until all 

 is added. If cow's milk\cannot be got, use as a substitute two 

 cans of condensed milk diluted with twice its bulk of water. 

 It is claimed by some that this diluted kerosene emulsion, 

 when properly prepared, so that the oil does not separate, is 

 more effective than the alkaline washes, and that it does not 

 injure the trees. 



For the application of these fluids several forms of portable 

 pumps have been devised, in the selection of which the fruit- 

 grower should be guided by his own requirements. Where 

 the orchard is large, it will pay to purchase an efficient instru- 

 ment for this purpose. It is stated that, with a suitable pump 

 and nozzle for spraying, from one to two hundred trees can 

 be thoroughly treated in a day. 



Since by far tho greater portion of the injury caused by 

 insects to orange-trees is effected by the scale-insects, it is im- 

 portant that prompt measures be adopted to destroy them, 

 and that every precaution be taken to prevent their introduc- 

 tion into districts hitherto exempt from them. Many localities 

 have been colonized by these pests through the return of 

 empty fruit-boxes from infested districts. These may be dis- 

 infected by dipping them for at least two minutes in boiling 

 water containing not less than one pound of potash or half a 



