REPORT OF THK STATE ENTOMOLOGIST 2 2^ 



Washington, during the past year (1894), have been so varied and appar- 

 ently SO thorough that it would seem that the results attained might be 

 accepted, without further experimentation, for future guidance in our 

 operations against this scale. During the latter part of the year twenty- 

 nine different washes were tested by experienced entomologists from the 

 Bureau, upon badly infested trees in Charles county, Maryland. In 

 summing up these results, Mr, Howard has stated : " The only perfect 

 results which have been reached have come from the application of two 

 pounds or more of commercial whale-oil soap to a gallon of water, and 

 from the application of a resin wash of six times the normal summer 

 strength. The effects following the application of these washes leave 

 nothing to be desired. In all cases the most careful search over the 

 sprayed trees has failed to show a single living scale." 



Unfortunately, both of the above-named washes are somewhat ex- 

 pensive, as the lowest price at which the whale-oil soap can be purchased 

 is four cents a pound by the barrel, making the wash to cost eight 

 cents per gallon. The resin wash is still more expensive. When large 

 orchards are to be treated, the cost is quite an item, but the intelligent 

 fruit-grower will not hesitate when convinced that the choice lies be- 

 tween the expense of the wash and the loss of the trees. 



The above are known as " winter washes," since they may only be used 

 without serious injury to the tree during its winter dormancy. Later, it 

 would not be safe to apply them unless in a considerably diluted form, 

 when they would only suffice to destroy a portion of the scales, 



Ho7)ie-7tiade whale-oil soap. — For those who would prefer making the 

 soap for themselves, at a less cost than if purchased by a small quantity 

 in market, Mr. Howard has given the following formula: Potash 

 lye, one pound; fish oil, three pints; soft water, two gallons; dissolve the 

 lye in water and add the oil on bringing the mixture to a boil; boil for 

 about two hours and then add sufficient water to make up for the evapo- 

 ration. This will make about twenty pounds of soft soap, equivalent to 

 about five pounds of the hard. 



Tlie winter resin wash. — The composition and proportions given for 

 this are as follows: Resin, 120 pounds; caustic soda, 30 pounds; fish 

 oil, 15 pints; water sufficient to make 100 gallons. The resin and soda 

 are broken up and, together with the fish oil, are placed in a large kettle, 

 sufficient water being added to cover them. The whole is then boiled 

 for several hours, or " until the compound will mix properly in water 

 without breaking up into yellowish flakes " {Insect Life., vii, p. 293), 



16 



