Rodent Injury to Trees. 451 



to injury by rodents, the following suggestions for repellent washes 

 are advanced tentatively: — 



{a) Equal parts of portland cement, sulphur, and slaked lime, 

 mixed with sour skimmed milk. 



(6) A mixture of 1 lb. each of sulphur, lime, and soap, in 1 

 gallon of water. The soap should be dissolved in hot 

 water and the sulphur and lime stirred into the liquid. It 

 mixes readily. Use Mhile warm. Tf quicklime is used, 

 it should be slaked in a little water, and then added to 

 the soap and sulphur mixture. 



(c) A mixture of sulphur, lime, and glue. Dissolve 1 lb. of 

 glue in 2 to 4 gallons of water, then, if slaked lime is used, 

 mix the sulphur and lime together and stir into the glue 

 solution. 



Tobacco dust may be added to anjr of tTie above washes if desired. 

 The mixtures should be applied to the trees whenever there is danger 

 of rodent attack. 



Poison Washes. 



The virulent soluble arsenical compounds such as arsenite of 

 ■soda must never be used in washes, as serious injury or even the death 

 of the tree will be the result. The extent of injury wnll depend upon 

 the strength of the solution and the age of the tree. There are little 

 data available regarding the use of insoluble arsenicals. One case 

 has come to the notice of the writer in which fruit trees were painted 

 "with a fairly strong wash of lead-arsenate paste and water. The 

 treatment did not prove to be very effective, as hares continued to 

 attack the trees. 



Strychnine washes have been used in Idaho, California, and other 

 western States of America in recent j-ears. A typical one is j)repared 

 as follows : Dissolve 1 ounce of strychnine sulphate (the hydrochloride 

 could be used) in 3 quarts of boiling water and h. lb- of thy laundry 

 starch in 1 pint of cold water, and then mix the two solutions 

 together. Boil until the paste is clear, and while boiling add 6 

 ounces of glycerine, stirring thoroughly. When cool enough, apply 

 with a paint brush to the tree trunk. 



The above quantity will do for a large number of small trees. 

 It is said that rodents attacking the trees are soon killed by the poison, 

 and that there is practically no injury to the trees by the wash. 



It should be remembered that strychnine is a deadly poison, and 

 must be handled with care. 



Poison Baits for the Destruction of Rodents. 



When rodent pests become numerous, destruction is always advis- 

 able, and in plantations it is the only practicable remedy, as applying 

 washes to thousands of trees is out of the question. Poisoning is the 

 cheapest method of destruction. Of the different poisons which might 

 be used strychnine is by far the best, and is the only one that will 

 be considered here. 



Hares. — When these cannot be kept in check by shooting, they 

 are sometimes poisoned by introducing- a little strychnine into fruits 

 ■<or vegetables, and placing these about the orchard, either on the 



