128 



of 1 oz. to 8 or 10 gallons gave very satisfactory results, and was found 

 to be quite safe. Notes are given on the life-history of P. hrassicae 

 in Armstrong, as distinguished from that in Lower Fraser Valley, 

 where former observations had been carried out. 



Gibson (A). Further Data on the Control of the Cabbage Root 

 Maggot in the Ottawa District. — 50th Ann. Kept. Ent. Soc. 

 Ontario, 1919, Toronto, 1920, pp. 71-73. [Received 8th January 

 1921.] 



Experiments with corrosive sublimate for the control of PJiorbia 

 brassicae (cabbage root maggot) show that 1 oz. in 10 gals, of water 

 gives as good results as 1 oz. in 4 gals, of water. Three applications 

 proved equal in efficiency to four. Tests with the use of discs and 

 tobacco and hme show poorer results. The corrosive sublimate 

 treatment had no deleterious influence either upon the plants or in the 

 relative number of soil organisms present in treated as compared 

 with untreated soil. It also seemed to have a stimulating effect 

 upon the growth of the plants. 



Caesar (L.) & Huckett (H. C). Cabbage Maggot Control.---56>//z 



Ann. Kept. Ent. Soc, Ontario, 1919, Toronto, 1920, pp. 73-77. 

 [Received 8th January 1921.] 



The results of tests with insecticides on radishes infested with Phorhia 

 [Chortophila) hrassicae (cabbage maggot) are shown in tables. Corro- 

 sive sublimate was the only substance that gave satisfactory results. 

 If applied stronger than 1 : 1,000 to young plants it temporarily 

 weakens them ; even at this strength too heavy soaking around very 

 young plants may cause a sickly appearance of the foliage for a few 

 days. The best time for treatment with corrosive sublimate has 

 not yet been determined. Even if applied within 24 hours of sowing the 

 seed, it appears to have no injurious effect upon germination. Its applica- 

 tion has a decidedly beneficial result upon the size, shape and quality 

 of the radishes. Tobacco dust and soft coal soot both gave excellent 

 foliage, but the radishes were inferior. Both of these substances, and 

 also a mixture of tobacco dust, sulphur and lead arsenate powder, 

 were useless, and in most cases seemed to encourage the presence 

 of the fly. 



Corrosive sublimate does not seem to have any deterrent effect 

 on the hatching of the eggs of P. hrassicae, neither do the larvae seem 

 to be killed by contact with it, but possibly its repellent action may 

 cause the latter to wander away from the plant and so bring about 

 their death. Tests show that the pupae are not kiUed by this insecti- 

 cide. 



Strickland (E. H.). The Present Status of Mill-infesting Pests in 



Canada. — 50th Ann. Kept. Ent. Soc. Ontario, 1919, Toronto, 

 1920, pp. 77-80. [Received 8th January 1921.] 



An investigation among flour mills, bakeries and warehouses has 

 shown that the chief pest in flour mills is Ephestia kithniella (Mediter- 

 ranean flour moth), which is sometimes so numerous that the silk 

 spun by the larvae clogs the elevators so that they have to be dis- 

 mantled. Flour beetles {Triholiiim spp.) are almost as numerous 

 in Canadian mills, but as they do not interfere with the process of 



