329 



Gibson (A.). The Pea Weevil. — Canada Dept. Agric, Ottawa, Crop 

 Protection Leaflet no. 9, March 1918, 2 pp., 1 fig. [Received 

 5th June 1918.] 



Bruchus pisorum, L. (pea bruchus) has increased to an important 

 extent in Ontario during recent years and has also appeared in a 

 few locahties in British Columbia. The eggs are laid on the pods 

 and hatch after a few days, the young larva eating through the pod 

 and attacking the seed, in which the insect remains throughout the 

 larval and pupal stages ; the mature beetle also frequently remains 

 in the seed until the following year. When very numerous, however, 

 the adults may leave the peas in late summer or autumn and hibernate 

 beneath rubbish or in barns and other outbuildings. These return 

 to pea plants while the pods are forming, and those planted with the 

 seed emerge through the soil and also fly to pea-pods to oviposit. 

 All growers are urged to watch for the appearance of any stage of the 

 insect and are warned against sowing infested seed unless it has first 

 been fumigated. For this purpose, carbon bisulphide should be used 

 in the proportion of 1 lb. to every 100 bushels of seed ; the exposure 

 should last 48 hours in an air-tight bin or other receptacle. This 

 should be done directly after the crop is gathered. B. pisorum does 

 not breed in dry seeds ; consequently, if the seed is kept in tight 

 bags for a year, any beetles present will emerge and die. For small 

 growers this is an efi ective protection. Another method of destroying 

 the beetles in the seed is by pouring about half a gallon of coal-oil 

 over a barrel containing about 5 bushels. If every seed can be drenched 

 the oil will penetrate and kill the weevil. If seeds that are used in 

 sowing are found to contain this pest, they should be immersed in 

 scalding water for about a minute and subsequently cooled by pouring 

 cold water over them. 



Sanders (G. E.). Arsenate of Lime (Calcium Arsenate). — Canada 

 Dept. Agric, Ottawa, Crop Protection Leaflet no. 10, [n. d.], 4 pp. 

 [Eeceived 5th June 1918.J 



Calcium arsenate, on account of its efiiciency and low cost, is 

 highly recommended as an insecticide, as it replaces lead arsenate 

 or lead or zinc arsenite, which are at present costly and difficult to 

 procure. It is however advisable in the present state of investigations 

 to use it as a spray only for apple, potato and pear ; for tender 

 foliage, such as plum, cherry or peach, it is not regarded as safe. 

 Used alone, it causes scorching and must therefore be combined 

 with certain other sprays. 



The form in which it is recommended is the commercial dry powder, 

 containing 40 per cent, arsenic oxide in the form of tri-calcium arsenate 

 and less than 1 per cent, soluble arsenic, and so finely ground that 

 1 lb. of the dry material occupies 80 cubic inches. When 10 parts 

 of either water-slaked or hydrated hme is used to 1 part calcium 

 arsenate, the material can be apphed to apple and potato foliage 

 without injury. Calcium arsenate with lime-sulphur has invariably 

 given shghtly better results in the control of fungous diseases than 

 lead arsenate with lime-sulphur. Trees sprayed vdih. the former 

 combination have in three years' experiments given more apples 



