624 EXPERIMENT STATION RECORD. 



in foul water even more was necessary. J. B. Smith stated that in his experience 

 even greater strength was necessary to secure satisfactory results. W. E. Britton, of 

 Connecticut, presented a brief paper showing that the fall webworm was partially 

 double-brooded in Connecticut; and Henry L. Viereck, of Philadelphia, nave a few 

 observations upon the museum pest. 



The Coffee Leaf Miner (Leucoptera coffeella) was discussed liy M. T. Cook. This 

 is one of the most injurious coffee pests in the West Indies and causes great losses in 

 Cuba and Porto Rico. On some coffee estates 56 per cent of the leaves were affected. 

 The life history of the pest was discussed by the speaker with particular reference to 

 methods of treatment. Spraying against the larvae in the leaf is of little avail. It 

 is found possible, however, to control the insect quite thoroughly by repeated spray- 

 ing against the pupa by means of kerosene emulsion containing 1 part kerosene, 1 part 

 whale-oil soap, and 8 parts water. When numerous applications of this remedy 

 were made, slight injury to the leaves occur, but this injury was not of great im- 

 portance. On the grounds of the Cuban Experiment Station spraying experiments 

 were begun August 18 and continued to November 5 at frequent intervals. The 

 results of this experiment indicate that the treatment is quite effective. 



Some notes on the Fumigation of Household Insects and their Eggs with Hydro- 

 cyanic-Acid Gas was the title of a paper by J. L. Phillips. Fumigation with hydro- 

 cyanic-acid gas was tested in the destruction of bedbugs in living apartments. The 

 buildings were badly infested. The doors were kept closed for 2 days, at the end of 

 which time it was found that all fumigated eggs were dead. Repeated examinations 

 of the apartments disclosed the presence of very few living insects, and fumigation is, 

 therefore, considered effective for bedbugs. Good results were also obtained from 

 the use of the same method in destroying the croton bug in dwelling houses. 



A. F. Burgess read a paper on The Fumigation of a Fruit House for Controlling the 

 Codling Moth. Since many larva? of the codling moth do not leave the fruit until it 

 is in storage, it appeared desirable to test the effect of fumigation with hydrocyanic- 

 acid gas upon codling moth larvae in storage rooms. In the experiment reported by 

 the speaker the larvae were in a fairly active condition and were thoroughly exposed 

 to the action of the fumes. The formula used was 1 oz. of potassium cyanid, 1 thud 

 oz. of sulphuric acid, 3 fluid oz. of water for each 100 cu. ft. of space. The period of 

 fumigation was 20 hours. At the end of the period the odor of the gas was still 

 quite strong in the storage house. An examination was made of numerous larvae 

 with the result that less than 45 per cent appeared to have been killed by fumiga- 

 tion. Some of these larvae were injured by handling, so that the speaker believes 

 that really less than 40 per cent were killed by the treatment. The cost of the treat- 

 ment was so slight that it would be an economical method if effective. Apparently,' 

 however, it is not sufficiently effective, and it was recommended that screens be used 

 in storage houses for capturing the moths. 



The Cottony Maple Scale, an Unusual Outbreak, and Experiments with Insecti- 

 cides was discussed by S. A. Johnson. The speaker's experience with this pest was 

 had chiefly in Denver. Several kinds of insecticides were used as winter treatment, 

 especially since it appeared that remedies could best he applied in the winter. A 

 number of preliminary laboratory experiments were made in testing the value of 

 lime-sulphur-salt wash, kerosene emulsion, and whale-oil soap in destroying the 

 cottony maple scale. Apparently the natural mortality in this species is about 50 

 per cent during winter. The results obtained in laboratory experiments with insecti- 

 cides were not decisive. Outdoor applications were made in Curtis Park, Denver, 

 during which kerosene emulsion, tobacco decoction, skabcura, tree soap, zenoleum, 

 lime-sulphur-salt, whale-oil soap, etc., were used. The most effective remedies as 

 determined by these experiments are kerosene emulsion in various strengths above 

 10 per cent, and whale-oil soap at the rate of 1 lb. to 1 gal. of water. Tobacco decoc- 

 tion, skabcura, and lime-sulphur-salt wash appeared to be quite ineffective. 



