56 EXPERIMENT STATION RECORD. 



In a wet climate a rain a day or two after the spraying would tend to wash out 

 the thiosulphate, and no sulphite could be formed. The insecticidal properties 

 would then depend upon the sulphur left upon the tree. "It is possible that the 

 thiosulphate itself has some value as an insecticide. If so, it would be manifested 

 much more strongly in a dry climate than in a wet climate, where the thiosulphate 

 would be gradually or at once washed off." 



An inquiry into the cyanid method of fumigating nursery stock, \V. 

 Newell (Ga. Bd. Ent. Bui 15, pp. 24, figs. 3).— Nurserymen in Georgia have been 

 for several years required to fumigate nursery stock with hydrocyanic-acid gas. 



On account of the different results obtained from the application of this method 

 under different conditions, the author undertook an investigation of the cause of this 

 apparent variation in the strength of potassium cyanid. For this purpose analyses 

 and tests were made of samples of potassium cyanid sold by various dealers. It was 

 found as a result of this investigation that failure to secure satisfactory results in 

 fumigation is frequently due to the use of adulterated potassium cyanid. The 

 amount of gas generated when the cyanid is added to the mixture of acid and water 

 is somewhat greater than when the latter mixture is poured over the cyanid. 



It was found that the presence of common salt in the cyanid causes a reduction in 

 the amount of gas available for destroying insects. Common salt is most frequently 

 used in the adulteration of potassium cyanid. The effectiveness of a sample of cya- 

 nid is not indicated by an analysis which shows it to be high grade according to the 

 amount of potassium cyanid present unless the analysis also shows the absence of 

 chlorids, nitrates, and other adulterants. 



In the study of the effect of temperature upon the formation of hydrocyanic-acid 

 gas it was found that the temperature produced by the mixture of 2 fluid ounces of 

 sulphuric acid and 4 fluid ounces of water is apparently the optimum temperature 

 for the volatilization of the gas. 



Notes on a light trap in Hertfordshire, P. J. Barraud {Ent. Mo. Mag., 2. ser., 

 16 (1905), No. 182, pp. 43, 44)- — The author has made use of a lantern trap for catch- 

 ing lepidoptera since 1898. During this period over 300 species of lepidoptera have 

 been captured. The trap is attached to a first-floor window about 14 ft. from the 

 ground. The author believes that the want of success with traps in many cases 

 is due to the fact that they are placed too near the ground. It is believed that an 

 elevation of 20 ft. is desirable for a great many species of lepidoptera. 



Report of the New Jersey State Agricultural Experiment Station upon 

 the mosquitoes occurring within the State, J. B. Smith (New Jersey State Sta., 

 1904, pp. y A- 482, pis. 47, figs. 89) . — In this report the author summarizes the results 

 of some investigations regarding the anatomical characters, habits, distribution, nat- 

 ural enemies, and means of combating the mosquitoes which occur in New Jersey. 



Special chapters are devoted to the hibernation of mosquitoes, the agency of these 

 insects in carrying diseases, a description of species of mosquitoes occurring in New 

 Jersey, the classification of mosquitoes with a key as an aid to their determination, 

 and various local problems in the eradication of the mosquito nuisances in different 

 parts of the State. The author has collected a large fund of information which will 

 be of value in the further study of the mosquito problem. This is particularly true 

 of the sections on breeding places, natural enemies of the mosquitoes, and artificial 

 insecticide measures. 



Among the various insecticides which were used in the destruction of mosquitoes 

 none proved more efficient against the larvae than kerosene oil. Phinotas oil is use- 

 ful in sewer catch-basins, cesspools, and other pools of water in which there are no 

 fish. This oil, however, is not soluble in salt or brackish water and can not, there- 

 fore, be used in salt marshes. Carbolic acid and cresol preparations were found to 

 be effective when used in their proper strengths, but were found too expensive. 

 Permanganate of potash was carefully tested and found to be practically without any 



