The Canadian Horticulturist. 67 



week. The young scale insects were noriced on May 19th at Riverside, Md., 

 and the females, vi\nparous in habit, gave birth to young for a full month. This 

 was upon peach trees, and it was found that the resin wash killed the scales 

 more quickly than the very diluted kerosene emulsion, and, as Mr. Howard 

 points out, this rapidity of the work is important, since where a full-grown female 

 is sprayed with kerosene emulsion, she may live for three or four days, during 

 which time she may bring forth young ; whereas, if sprayed with the resin wash, 

 fewer young scales are produced. The resin wash, however, is readily carried 

 off by the rains, while the kerosene is more resistant. 



In Professor J. B., Smith's investigations in Pennsylvania, it is recorded 

 (Insect Life, VII, p. 159) that, "he has visited the locality at Atglen, Pa., and 

 found that in an orchard of over 7,000 trees, all of certain varieties, and a few of 

 others, were infested by the scale. As a result of his recommendations, kerosene 

 emulsion has been applied three times to most of the trees at intervals of ten 

 days, up to the first week in June. The treatment has been absolutely success- 

 ful." 



For winter washes the kerosene emulsion and resin washes may be made 

 stonger. The stock kerosene emulsion has been used diluted with only four and 

 a half parts of water, and for the resin wash the same ingredients were used in 

 the following proportions : Resin, 30 lbs ; caustic soda, 9 R)s.: fish oil, 4^2 pints ; 

 water, 100 gallons. 



" The most favored winter remedy in California, however, is the lime, salt, 

 and sulphur mixture. This consists of unslacked lime, 10 lbs.; sulphur, 5 5)S ; 

 stock salt, 5 ft>s.: water to make 15 gallons. This wash will do great damage to 

 the trees if applied during the growing season, a/td should be used only in winter. 

 All the sulphur and half the lime are placed in a kettle and 8^^ gallons of 

 water added, after which the contents of the kettle are boiled briskly for about 

 an hour. The solution, which at first is yellow from the sulphur, will turn ver>- 

 dark brown, assuming more or less of a reddish tint, and will finally change 

 from a thick batter to a thoroughly liquid condition, the products being ordinary 

 sulphide of lime. All the salt is added to the remaining 5 pounds of lime and 

 the latter slaked, after which the slacked lime and salt are added to the sulphide 

 of lime already obtained, the whole being then diluted with water to make 15 

 -gallons. This should be strained before application, as it does not form a 

 perfect liquid solution on account of the considerable quantity of undissolved 

 lime, which will soon sink to the bottom unless the solution is constantly 

 stirred while being sprayed." 



The third method of fighting scale insects is known as the Gas Treatment. 

 This has been extensively used in California but is an expensive operation, and 

 the materials necessary are very poisonous and dangerous to have about. It 

 consists, briefly, of covering the trees to be treated with an air-tight tent and then 

 filling the tent with the poisonous fumes of hydrocanic acid gas, which is gener- 

 ated by placing i oz. of cyanide of potassium, i fluid oz. of sulphuric acid, and 



