31 



be applied with safety, the question of their presence must depend 

 on the determination of adults in the autumn. 



The insects used for the experiments were kept out of doors and 

 exposed to all changes of weather. A. avenae was sprayed on 7th 

 December, 9th January, 10th February, and 1st, 10th and 21st 

 March ; A. pomi on 18th February, 3rd, 12th and 21st March. 

 Sprays cannot be applied with safety after the buds show green. 

 A list of the many insecticides tested is given with comparative tables 

 of the results obtained ; from these it is evident that concentrated 

 liquid lime-sulphur (1-9) is superior to all other sprays when used at 

 their respective recommended strengths and killed 92 to 94% of all 

 the eggs of A. avenae and 89 to 96% of all those of A. pomi. Used at 

 a strength of 1-6 it is slightly more efficacious, but does not even then 

 effect a complete destruction. The addition of 1 gm. per 100 cc. of casein 

 lime, composed of 50% casein (lactic) and 50% hydrated lime, greatly 

 increased the effectiveness of this spray. Dry lime-sulphur is less 

 effective. At a strength of 15 lb. to 50 U.S. gals, only 78%, of the 

 eggs of A. avenae were killed. Used as a dust it proved even less 

 effective. Barium sulphur at the rate of 15 lb. to 50 U.S. gals, was 

 somewhat superior to coarse dry lime-sulphur, but very inferior to 

 concentrated liquid lime-sulphur. The most effective spray after 

 concentrated liquid lime-sulphur was sodium-sulphur (commercially 

 known as soluble sulphur, and largely consisting of sodium poly- 

 sulphide) at the rate of 15 lb. to 50 U.S. gals. The addition of nicotine 

 (1-500) increased the efficacy of all sprays. A combination of fish 

 oil soap (1 gm. per 50 cc.) and nicotine (1-500) killed 99 per cent, of the 

 eggs of A. avenae when applied on 21st March, but was decidedly 

 less effective when applied earlier. Nicotine (1-500) added to sodium 

 sulpho-carbonate (1-9) gave almost complete control and may prove 

 as effective as concentrated liquid lime-sulphur, though further observa- 

 tions are necessary, as its effect upon the plants is not known. The 

 addition of ordinary laundry soap at the rate of 1 gm. per 200 cc. to 

 sodium sulpho-carbonate apparently made no difference, whereas 

 the addition of fish oil soap in the var}ang strengths of 1 gm.-50 cc, 

 1 gm.-lOO cc, and 1 gm.-200 cc, materially reduced its efficacy. Other 

 insecticides tested included hydrated lime, the toxicity of which never 

 exceeded 81 per cent. This was slightly increased by the addition 

 of casein-lime. Experiments with the miscible oil, " scalecide," 

 were not successful. 



The most important reaction of all insecticides is their toxic effect 

 on the embryo. The period of maximum susceptibility of the eggs 

 is when they commence to hatch. Contrary to previous experiment* 

 [loc. ciL], the susceptibility of the eggs of A. avenae and A. pomi to 

 various sprays are approximately the same. 



Crosby (C. R.) & Leonard (M. D,). An injurious Leaf-miner of 

 the Honeysuckle. — Jl. Econ. Entom. Concord, N.H., xii, no. 5, 

 October 1919, pp. 389-392, 6 figs. 



A serious outbreak of Phyllorycter (LithocoUetis) fragilella, Frey 

 & Boll, was noticed in 1917 in New York State on Belgica honey- 

 suckle. The damage caused necessitated the substitution of hard 

 wood instead of green-cuttings for propagation. 



