1006 EXPERIMENT STATION RECORD. 



placed by the plants, which were covered severally with washtubs^ 

 hay cai)S, and muslin. The mnslin covcriiii;s proved insuilicieiit to 

 retain the fumes and the general results of the experiments were not 

 altogether satisfactory, in several instances the lice surviving^ exposure 

 to the fumes for an hour. Experiments were also made with hydro- 

 cyanic acid gas, generated in a small dish, and the plants covered for 

 varying lengths of time. These experiments were very successful and 

 the treatment is recommended for effectiveness and cheapness. 



The use of bisulphid of carbon and hydrocyanic acid gas on 

 low-growing plants, H. Garman [Kentucl-y Sta. Bui 53, pp. 141-150, 

 ■fig, i). — An account of experiments with the above chemicals on the 

 melon louse and rose aphis. The carbon bisulphid was used by intro- 

 ducing a tablespoopful of the fluid under a tub inverted over a melon 

 hill, which was left undisturbed for about an hour and a half. By this 

 means the majority of the aphides were killed, while the vines were 

 not injured. In exj)eriments with hydrocyanic acid gas a small cloth 

 tent 3 ft. in diameter at the bottom and about 3 ft. high was used. 

 This was supported by means of stakes over the plants to be treated, 

 and beneath it was jilaced a saucer containing 9 cc. of water and 3 cc. 

 of commercial sulphuric acid. To this 3 gm. of potassium cyanid was " 

 added. It was found that 4 minutes was a sufficient length of time to 

 kill all insects present, with the exception of mites, and the method is 

 recommended as being quick and eftective for exterminating insects on 

 single plants. A rosebush infested with the rose aphis was sprayed 

 with antinonnin, 1 gm. to 1 qt. of water, but the lice were not com- 

 pletely destroyed. Hydrocyanic acid gas was then a])plied for 10 min- 

 utes, killing the insects, but also injuring the leaves ol the plant. 



The use of arsenites on tobacco, H. Garman {Kentuely Sta. Bui. 

 53, pp. 125-143, Jigs. 6) — This paper was in main part read before the 

 section on entomology of the Association of Agricultural Colleges and 

 Experiment Stations at its meeting in Washington in November, 1894 

 (E. S. K., 6, p. 2()5). In addition to the paper as there presented is 

 given a discussion of various forms of apparatus for spraying tobacco, 

 5 of them being figured. A cart sprayer is believed to be best, but for 

 ordinary purposes some form of knapsack sprayer is recommended, 

 preferably one with a force pump attachment. A nozzle that causes 

 the poison to issue in a fine mist is to be preferred. Spraying with 

 1 lb. of Paris green to 160 gal. of water is advised, to be first done 

 about July 4 and followed by about 2 subsequent applications at inter- 

 vals of 2 weeks. At least 2 weeks must elapse between the last spray- 

 ing and the cutting of the plants. 



Spraying for codling moth, H. Garman [Kentuclcy Sta. Bui. 53, 

 pp. 119-125, fig. 1). — The results of experiments in spraying apple trees 

 with arsenicals to determine their value as effective means of combat- 

 ing the codling moth Two trees of Janet, about equal size, were 



