395 



Macoun (W. T.). The Potato in Canada, its Cultivation and Varieties. 

 — Canada Dept. Agric. Div. Hortic, Ottaiva, Bull. no. 90 (Popular 

 Ed.), 1918, 16 pp., 3 figs. [Eeceived IGth July 1918.] 



Damage to the leaves of potato plants by Leptinotarsa decemlineata 

 (Colorado potato beetle) may be avoided by spraying immediately 

 the larvae appear, which is in about a week after the eggs are laid. 

 "WTiere labour is cheap it is also advisable to handpick the adult 

 beetles before oviposition. 



The best poisons to use are Paris green and lead arsenate ; either 

 of these may be applied in both the wet and dry forms. Paris green 

 should be used in the proportion of 8 oz. to 40 gals, water, at any time 

 that the weather is fine. If it is to be used as a powder, the dusting 

 should be done while the dew is on the foliage, the mixture consisting 

 of 1 lb. Paris green to 50 lb. slaked lime, land plaster (gypsum) or any 

 perfectly dry powder. Lead arsenate paste at the rate of 2 to 3 lb. 

 to 40 gals, water, or powdered lead arsenate at the rate of 1 lb. to 

 1| lb. adheres to the foliage better than Paris green, though it does 

 not kill quite so rapidly. Hence a mixture is recommended consisting 

 of 8 oz. Paris green and IJ lb. lead arsenate paste to 40 gals, water. 



The cucumber flea-beetle [Epitrix cucumeris] frequently causes 

 great damage by making small holes in the leaves, thus inducing the 

 attacks of potato fungus, but it may be controlled by spraying with 

 Bordeaux mixture and lead arsenate. 



Davis (J. J.) & Turner (C. F.). Popular and Practical Entomology, 

 Experiments with Cutworm Baits. — Canadian Entomologist^ 

 London, Ont., \, no. 6, June 1918, pp. 187-192. 



Owing to the ever-increasing price of bran, experiments have been 

 midertaken in Indiana to test the suitability of sawdust as a substitute 

 for it in poison-baits. The regulation bran mash composed of 1 lb. 

 poison to 25 lb. filler (bran or sawdust), with 2 quarts molasses, 6 

 lemons and water as needed, was made up according to 3 formulae, 

 containing respectively Paris green and bran, Paris green and sawdust, 

 and white arsenic and bran, and these mixtures were used in a field 

 badly infested with Agrotis ypsilon (greasy cutworm). The ground 

 was treated on 9th July, maize was replanted on 14th July, and 

 counts made on 23rd July showed that sawdust gave distinctly good 

 results, though not so good as those with bran. When used at the 

 rate of 5 lb. to the acre, the figures were : — Paris green and bran, 

 2 per cent, plants attacked ; white arsenic and bran, 3 per cent, 

 plants attacked ; Paris green and sawdust, 5 per cent, plants attacked ; 

 control plot, 50 per cent, plants attacked. 



Similar experiments were conducted for the control of Cirphis 

 nnipuncta (army worm). The poisons were used in the proportion 

 of 1 lb. to 25 lb. filler and 1 lb. to 50 lb. filler, the bait being scattered 

 at the rate of 10 lb. per acre. Examinations made two days later 

 showed about 75 per cent, dead in the sawdust-bait area and practically 

 all dead in the area treated with bran. Similar laboratory experiments 

 confirmed the view that sawdust has some value, and can be 

 recommended when it is impossible or very difficult to obtain bran ; 

 but when it is used, a second application will probably be necessary. 



