376 JOURNAL OF ECOMONIC ENTOMOLOGY [Vol. 12 



1-6 or 1-9 (with and without casein-hme) combined with nicotine 

 1-500 show 100 per cent kill except one application of lime-sulfur 1-9 

 plus nicotine, 1-500 (j) made on March 10 (99 per cent kill). Chart 

 V, where the eggs of A. pomi were used in all the experiments, also 

 shows an increase in the efficiency of a combined spray of lime-sulfur 

 and nicotine over lime-sulfur alone (a, b, j, and k. Chart 5). 



Nicotine added to fish-oil soap also increased its efficiency (Exp. 

 33, 34, 35, Table I and Expt. 16-p, 17-p, 18-p, Table II or Charts I, 

 IV and V). A combination of fish-oil soap, 1 gm.-50 cc. and nicotine, 

 1-500 kills 99 per cent of the eggs of A. avence, when applied on March 

 21, but earlier applications of the same spray are decidedly inefficient. 

 Nicotine was also added to "Scalecide" 1-15, 1-25 and 1-40 in a few 

 experiments on March 18 (not shown in tables), and the efficiency of 

 the spray was increased 20 to 30 per cent, but in no case was there a 

 complete kill. The best combination proved to be "Scalecide," 1-15 

 plus nicotine, 1-500 which killed 98 per cent of the eggs of A. avence. 

 Nicotine was also added to varying strengths of linseed and cotton- 

 seed oil emulsions (2 cc.-8 cc. to 98 cc.-92 cc. respectively, plus laundry 

 soap 1 gm.-lOO cc.) but with both oils a reaction occurred which caused 

 the two oils to form large globules that came to the surface at once. 

 This was probably due to the fact that the oil solutions gave an acid 

 reaction. This material was difficult to spray and the efficiency of 

 the combined spray was only increased slightly (Expts. not recorded in 

 table). Nicotine, 1-500 added to sodium sulfo-carbonate 1-9 gave 

 almost complete control (99.7 and 100 per cent) when sprayed on 

 March 18 and March 21 on the eggs of A. avence and A. pomi (see 

 Tables I and II). It is probable that this substance may prove to 

 be as efficient as concentrated liquid lime-sulfur, 1-9 in killing the 

 eggs of A. avence, however, its effect upon plants particularly green 

 swollen buds is unknown. A few experiments at the laboratory indi- 

 cate that it would be unsafe to use the above strength on green 

 tissue. 



Other Sprays and Chemicals 



In addition to the foregoing experiments a large number were con- 

 ducted, particularly on the eggs of A. avence, with varying strengths 

 of sodium sulfo-carbonate, hydrated lime, "Scalecide," crude carbolic 

 acid and cresols, fish-oil soap, linseed oil emulsions and cotton-seed 

 emulsions. Some of the more important of these may be found in 

 Tables I and II and on Charts I, IV, and V, but the results of a large 

 number of them are not included in the tables or on the charts in this 

 paper. Each substance will be discussed separately and the signifi- 

 cant points brought out. 



