1893-] ENTOMOLOGICAL NEWS. 253 



been tested in as many directions as is needful, before its useful- 

 ness to the economic entomologist can be decided. Mr. T. D. 

 A. Cockerell sent a paper on the distribution of scale insects, and 

 another on a method of keeping slip records. Mr. D. W. Co- 

 quillett sent a paper on hydrocyanic acid gas as an insecticide, 

 describing the experiments that had been made with a variety of 

 gases for the destruction of scale insects. Mr. H. Garman read 

 a paper on illustrations for the economic entomologist. He re- 

 viewed the various methods now in use, pointing out their merits 

 and defects, and concluding that, after all, wood engraving was, 

 up to the present time, by far the most satisfactory process. 

 There was considerable discussion upon this subject in which the 

 claims of photography as a method of illustration were urged, 

 and some of the difficulties in reproducing from photographs 

 were explained and discussed. Mr. C. R. Gillette read a paper 

 on the use of arsenic and its combination as an insecticide, re- 

 viewing in a general way the experiments made with this sub- 

 stance, and discussing the scope of its combinations. This paper 

 was also discussed at some length. Mr. A. D. Hopkins pre- 

 sented a paper on note and record keeping for the economic en- 

 tomologist, in which he described at length his methods. In the 

 discussion on this paper it eventuated that no two men had pre- 

 cisely the same system, and that each had adopted the method 

 used by him, because of its seeming simplicity as applied to his 

 own work. Another paper on destructive Scolytids and their 

 imported enemy, also started considerable discussion in connec- 

 tion with a paper by Mr. Riley on and parasitic predaceous in- 

 sects in applied entomology, and another by Mr. J. B. Smith on 

 the economic value of parasites and predaceous insects. The 

 whole matter of the importation of parasites and predaceous in- 

 sects was fully discussed, and the question of the real substantial 

 value of insects of this character to the agriculturist, was fully 

 considered. The general tendency of opinion seemed to be that 

 the aid given by such insects had been considerably overestimated. 

 Mr. L. O. Howard read a paper on methods of studying the life- 

 histories of injurious insects, in which he detailed at some length 

 some of the contrivances in use in the United States Department 

 of Agriculture, and also read another note on mosquito treatment, 

 in which he gave the results of some further experiments in the 

 use of kerosene for the destruction of the larva of these pests. 



