752 EXPERIMENT STATION RECORD. 



on the young branches and does not cause the death of the trees except after 

 an infestation of considerable duration. Brief notes are given on the life 

 history and food plants of this pest. The author tried, apparently for the 

 first time, lime-sulphur-salt as a remedy for oyster-shell scale on maples. The 

 trees were sprayed in November and April, and it was found that the insect 

 could be controlled with satisfactory results and without injury to the trees. 



If only one application is possible the fall appears to be the better time. A 

 thorough application in the spring, however, may sometimes be even more 

 effective. Lime-sulphur-salt should be used only during the dormant season.^ 

 Kerosene emulsion gives excellent results If applied in May when the young 

 scales are just beginning to crawl about. 



Combating the oyster-shell bark-louse and other entomological problems, 

 Duke of Bedford and S. U. Pickering (Woburu Expt. Fruit Farm Npt., 6 

 (1906), PI). V + 235). — On account of the extensive injury caused to fruit grow- 

 ers by the oyster-shell bark-louse, the authors organized an elaborate and 

 thorough campaign for determining the most effective and practical remedies 

 against this pest. 



Winter applications of insecticides were made for tlie purpose of destroying 

 eggs and removing moss and lichens from the bark. The alkali wash generally 

 recommended for winter use is a 2 per cent solution of caustic soda and car- 

 bonate of potash. The experiments carried on by the authors, however, indi- 

 cate that carbonate of potash has very little effect and that the value of the 

 mixture is lessened by substituting any of it for a 2 per cent solution of caustic 

 soda. The best results were obtained by a mixture containing 2 per cent caus- 

 tic soda and 2 or 3 per cent of soap. The soda-soap wash destroys from 70 to 

 90 per cent of the eggs. 



Less satisfactory results followed the use of kerosene emulsions, since when 

 enough kerosene was added to be effective the trees were injured, and a suf- 

 ficient quantity of soap appeared to be too expensive. Further experiments 

 along this line, however, showed that a weak kerosene emulsion containing 

 2 per cent of caustic soda would destroy all of the eggs. This mixture con- 

 tains G per cent of kerosene and 0.5 per cent of soap, the preparation being 

 made of li lbs. of soft soap, 2 gal. of kerosene, and G lbs. of caustic soda per 

 30 gal. of v,-ater. 



The authors do not recommend the use of undiluted kerosene for spraying 

 purposes. Fumigation with hydrocyanic-acid gas in ordinary proportions also 

 had no effect on the eggs of the scale. For suimner treatment the use of a 

 weak kerosene emulsion containing 1.25 per cent of kerosene and 2.5 per cent 

 of soap is recommended. 



A summary is presented of the work which has thus far been done in this 

 country and elsewhere on the San Jose scale. In destrojing moss good results 

 followed the use of a 2 per cent solution of caustic soda. The authors also 

 obtained satisfactory I'esults from the use of lead arsenate as an insecticide 

 for leaf-eating caterpillars. 



Treating San Jose scale, T. B. Symons and A. B. Gaiian {MaryJand 

 ata. Bill. 11:2, pp. 1'1-HS, fly.<\ 7). — The aggressive orchardists of Maryland are 

 able to control the San Jose scale, but in a number of localities this pest affords 

 serious difficulties. Wherever osage orange hedges become infested the difli-' 

 culty of eradicating the San Jose scale is increased. 



A number of experiments wore tried with different insecticides in combating 

 the pest. IJme and suljihur mixtures were used containing from 20 to 30 lbs. of 

 lime and from 15 to 25 lbs. of suli>hur per 50 gal. of water. The lime-sulphur-salt 

 mixture, tested by the authors, \^'as made accoi'ding to the formula 20-15-10-50. 



