DISEASES AND PESTS OF PLANTS. 



59 



Control. This is a difficult pest to 

 control. Quite a number of remedies 

 have been experimented with, some of 

 which have proved more or less effective, 

 but in the main too expensive to be 

 of much commercial value. Preventive 

 measures should be adopted. Procure 

 some tarred felt paper, from which cut 

 small disks (as per illustration) about 

 4 inches in diameter. Similar disks 

 may be purchased ready made from the 

 Plant Protector Co., 25 South Water 

 Street, Rochester, N.Y., at $2 per 1,000 

 in lots of less than 5,000; larger 

 amounts at proportionally less rates. 

 The cutting-tool can be made by any 

 blacksmith. Place a disk around each 

 plant as soon as they are set out in the 

 permanent plantation. This will prove 

 a deterrent to the fly and is accepted 

 now as the most successful method for 

 small and large areas. In those sec- 



Fig. 19. Cabbage-root maggot. Adult female, 

 greatly enlarged. (From Bulletin Xo. 382, 

 Geneva, N.Y.) 



tions where seed-beds are raised in the open ground the young seedlings may be 

 screened by means of a cheese-cloth frame. 



Disks for the Protection, of Young Cabbage-plants. The disks are cut in the 

 shape of a hexagon (Fig. 1) from paper known as "single-ply tarred felt." The 

 tool used in cutting these disks can be made by any good blacksmith by reference 

 to Fig. 2. The blade or cutting-edge is formed from a band of steel bent into the 

 form of a half-hexagon, with an additional strip reaching from one end nearly to 

 the centre as shown in Fig. 2. The part making the star-shaped cut is formed from 

 a separate piece of steel bolted to the handle (a piece of 2- x 4-inch), and so 

 attached as to make a close joint with the blade. The edge of the blade is bevelled 

 from the outside all round, so that by removing the part making the star-shaped 

 cut the edge may be sharpened. In order to cut the disks, the tarred paper should 

 be placed on the end of a section of a log as figured (Fig. 3) for convenience and 

 rapid cutting. The lower edge of the paper should be notched as indicated in Fig. 4, 

 using only one angle of the tool ; then begin the cutting at the left side, placing the 

 cutting-edge as shown by the dotted line, Fig. 4. 



THE CABBAGE-APHIS (Aphis brassica;). 



These insects are found in every cabbage-patch and may be found on all the 

 cultivated and wild cruciferae. Cabbages and turnips are, however, the most seri- 

 ously injured by them. 



Control. Nicotine sulphate, 1 part to 1,200 parts of water, plus 5 Ib. of whale- 

 oil soap to each 100 gallons of spray. Apply when the aphides are present on the 

 plants. 



