582 



15th Annual Report of the British Columbia Department of Agriculture, 

 1920,- Victoria, B.C., 1921, 132 pp., 7 plates, 26 Appendices. 



In 1920 the following measures were taken to control the codling 

 moth, Cydia [Carpocapsa) pomonella, in British Columbia. A spray 

 of 1 lb. lead arsenate (powder) to 40 gals, water was applied on the 

 25th May and again on the 29th June. Banding of trees was also 

 employed. The inspection work carried out against this moth is 

 described, and the necessity for car sterilisation to deal with the foreign 

 car situation is emphasised. During August and vSeptember tlie pear 

 and cherry slug [Eriocampoides limacina] caused considerable damage 

 to foliage where spraying was not practised. The Colorado potato- 

 beetle [Leptinotarsa decemlineata] is increasing its area of infestation. 



The early frosts in the autumn of 1919 and the following winter 

 of intermittent low temperatures killed many over-wintering insects. 

 This factor together with more efficient spraying methods made the 

 control of fruit tree pests in 1920 far more effective. During the last 

 two seasons the blister mite (Eriophyes pyri) has been abundant on 

 apples, having previously only infested pears. Sprays should be 

 applied at high pressure in spring before the buds begin to swell. 

 The apple aphis. Aphis pomi (mali), was not much in evidence in the 

 year under review ; the woolly apple aphis {Eriosoma lanigenmi) 

 was abundant, but owing to climatic conditions and efficient control 

 methods only slight damage was done. As the result of effective 

 spraying against the peach worm {Anarsia lineateila) in 1918 [R. A.E., 

 A, vii, 171] very little damage was reported. Other orchard pests 

 recorded were oyster-shell scale ( Lepidosaphes nlmi) and the flat-headed 

 apple-tree borer [Chrysohothris femorata}. 



Studies on the life-history and control of the imported onion maggot, 

 Hylemyia antiqua (PJiorhia cepanim), revealed the presence of a 

 partial third generation [see next paper]. The planting of a trap crop 

 is described, this method promising to be of great value. Following 

 the experiments of 1919 on Phorbia brassicae (cabbage root maggot) 

 [R.A.E., A, viii, 323] a spray was tested consisting of 1 oz. mercury 

 bichloride dissolved in 10 gals, water, the mercury salts having first 

 been dissolved in boiling water (1 oz. to every quart). The four 

 applications were made at the commencement of oviposition and 

 repeated at 10 days interval, 2 fluid oz. approximately being apphed 

 to each plant ; no injury to them was recorded. A comparative 

 experiment with tarred-felt discs and four applications of mercury 

 bichloride resulted in 75 per cent, marketable heads in the case of the 

 former, and 100 per cent, with the latter, the cost of which, with 

 labour and materials, was approximately |d. for every four plants. 



RuHM^NN (M. H.). Report on the Control of the Imported Onion- 

 maggot ( Hyiemyia nnfiqita). — l-jth Ann. Rcpt. B.C. Dept. 

 Agric, 1920, Victoria, B.C., 1921, pp. O 57-61. 



In 1919 the more essential points of the life-history and control of 

 the imported onion maggot ( Hylemyia antiqua) were determined 

 and are here described. A summary is given of the life-history of 

 this pest in 1920, when the main object was to prove the existence 

 of third generation adults. The first eggs were observed on 17th May, 

 the first larvae on 22nd May and the first pupae on 6th Jime. The 

 first adults of the second generation appeared on the 29th June. 



