ENTOMOLOGICAL SOCIETY OF ONTARIO. 79 



iron, manganese, mercury, etc., were considered. The cyanides of antimony and copper, 

 on theoretical grounds, seemed to promise best. The cyanide of antimony was totally 

 without effect at the rate of 10 pounds to 150 gallons of water. Cyanide of copper was 

 fairly effective, but too expensive for practical employment, three pounds to 150 gallons 

 being with this substance equivalent to one pound of Paris green to 150 gallons of water, 

 or three or four pounds of arsenate of lead to 100 gallons. Even where no practical 

 results seem to have been obtained, as in the above series of experiments, he pointed out 

 the value of the negative results ; in that the very fact that the merits of these substances 

 valuable for insecticides is better understood and limited. In connection with the vari- 

 ous experiments with insecticides he had occasion repeatedly to emphasize the extreme 

 vitality of the gypsy moth larva and its immunity to the action of poisons. 



Mr. Riley discussed the gypsy moth question at considerable length. He said he had 

 always been much interested in the gypsy moth work, and referred to the org^nal confer- 

 ence called by the State Board of Agriculture of Massachusetts, giving an account of 

 this meeting, and of the suggestions made by himself and others as to means of control- 

 ling the insect. These suggestions were necessarily based on experiences with our well 

 known common insects having somewhat similar habits, and had no basis in any actual 

 experience with the insect under discussion. He had recommended and believed that the 

 use of the arsenites is one of the most practical and effective means of control. There 

 can now be no doubt, however, that this insect is an exceptional one, and probably can 

 not be controlled by means which are quite effective against other insects, enemies of our 

 trees, having similar habits. Emphasizing the great damage which may be done by this 

 insect, he was convinced that its control and destruction are not only extremely necessary 

 to the State of Massachusetts, but are also of national importance. He had always been 

 in favor of extermination rather than of attempting to limit and control, but he pointed 

 out the very great difficulty of exterminating the species if the work is mainly directed 

 toward the destruction of the eggs, referring in this connection to his early statement in 

 this regard, in which the destruction of the eggs had not been deemed of prime import- 

 ance He thought, however, that in this particular he had been too extreme. He 

 pointed out the absolute futility of any efforts at extermination which did not promise 

 complete results. All that he had said in criticism of the Commission had been relative 

 to the operations prior to Professor Fernald's controlling connection with the work. He 

 heartily appreciated the value of the present methods as detailed by Professor Fernald. 

 He felt that if at the outset a supreme effort had been made, with the aid of a very large 

 appropriation, complete extermination of the insect could have been accomplished. He 

 gave a summary of some early work and his criticism of it. He was somewhat inclined 

 to question whether we are now justified in working on the basis of extermination through 

 a State commission, or whether it would not be better to eicourage the efforts of private 

 individuals wherever the Insect occurred, as is the case with other insect pests. He com- 

 plimented very highly, however, the present work of the Commission. In discussing the 

 subject of parasites, which had been referred to by Mr. Fernald, he was not inclined to 

 agree with the idea that the aim of the commissson at complete extermination detracted 

 at all from the necessity of undertaking the importation of foreign parasites. He said 

 that such introduction could be accomplished at comparatively slight expense and would 

 aid just so much the object of the Commission, pointing out also the greater usefulness of 

 European parasites over native ones if introduced without secondary parasites. This 

 would be particularly evident if his idea of the greater value of the destruction of the 

 larvjB rather than the eggs were conceded. 



In illustration of the great weight and value of Professor Riley's ideas on this sub- 

 ject, Mr. Fernald referred in the most complimentary way to the value of his long yeara 

 of labor in the field of economic entomology, which had resulted in a store of information 

 used and appreciated by all the workers of the world at the present day. He gave some 

 statistics of the injury capable of being done by the gypsy moth in the Stite of Massa- 

 chusetts, basing his deductions on the value of farm products and the estimated value of 

 forest and shade trees (Mr. Lintner interjecting in the latter connection that the Sara- 

 toga elms were insured by the State at $500 each). Taking the probable injury from 



