-"4 American Hortirultural iSociety. 



DiscrssioN ox pKor. riley's paper. 



3Ir. Okmcr, of Ohio — My experience in the use of arsenical 

 washes has been satisfactory. A weak infusion of London purple, 

 five or six ounces to a barrel of water, spravcd ov(!r my apple trees 

 has t^reatly reduced the damage from the codling moths. 1 use a 

 spraying apparatus which is mauutiictured at our place that is very 

 complete and thorough in its work. 



Mr. Leicers, of Nevada — The only insect pest which wc are 

 seriously troubled with is the codling moth. Our method of war- 

 fare against them is to trap the larvse in bands of rags or other 

 substances fastened about the trunks of the trees. These are re- 

 moved occasionally and the larvae destroyed. 



Prof. Klee, of California — Arsenic mixtures have been largely 

 and satisfactorily used in this state. White arsenic, London purple 

 and Paris green have each been employed. The London j)urple 

 must be used with care, as it will injure the foliage. Paris green 

 is effective and less dangerous to the foliage. Some trees will bear 

 a greater amount of the poisonous mixture than others. The Bell- 

 flower is more susceptible than the Pearmain. Sometimes a single 

 pound to 300 gallons of water will seriously injure the foliage. The 

 cotton sca';^ insect is the great enemy of the citrus orchards, but 

 even this can be successfully combated by the scientific applica- 

 tion of remedies. Hydrocyanic gas has been successfully used to 

 destroy the scale insect, and the experiments thus far seem to indi- 

 cate the practicability of the remedy. 



President Earle, of Illinois — I apprehend that it is the micro- 

 scopic fungi that orchardists of California have most to fear. It 

 seems to me that it will take all your energies to guard your fruits 

 against such pests. 



Prof. Cofjuildle, of California — Sprays of arsenic solutions are 

 injurious to the foliage of trees. The gas treatment is the best yet 

 tried. The tree is inclosed in an air-tight tent, which is lilled with 

 a mixture of hydrocyanic gas diluted with carbonic aeitl gas. If 

 the hydrocyanic gas be passed through sulphuric acid the proper 

 result will be attained. The cost of treating an orange tree amounts 

 to about ^L50, as retail prices are now, but this can be reduced at 



