30 PROTECTION OF PLANTS, 1916-17 



CABBAGE INSECTS 



By Arthur Gibson, Chief Assistant Entomologist, 



In Charge of Field Crop Insect Investigations, Department of Agriculture, 



Ottawa. 



There are a number of important insects which almost every year 

 effect more or less damage to cabbages in the Province of Quebec and, at the 

 request of the Secretary of the Society, I have assembled such information 

 concerning them, which I have considered would be of value to farmers and 

 gardeners. No attempt has been made to discuss the insects themselves or 

 their life-histories, the idea being to present the remedial measures which 

 in our investigations, covering a number of years, we have found of most 

 ser\ace. 



The Cabbage Root Maggot, Phorbia brassicae Bouche 



The Cabbage Maggot Fly resembles the com.mon house fly but is rather 

 smaller and more slender. About the time cabbages and cauliflowers are 

 set out, or when radishes and turnips appear above the ground, the flies may 

 be seen flying close to the ground depositing small, white, elongated eggs 

 on the stems of the plants or adjacent thereto. The eggs hatch in a few days 

 and the small white maggots at once burrow into and destroy the roots. 

 Injury may continue from May until autumn. 



Remedies.- — Cabbages and cauliflowers may be protected from injury 

 by placing around the stems, at the time they are planted out, a disc made of 

 one-ply tarred felt paper. The implement for making the discs is shown in 

 the accompanying figure at A. Some growers use a square disc. Such a 

 tool as is here illustrated can be made by any expert blacksmith. The blades 

 are made of steel bent in the form of a half hexagon and then taking an acute 

 angle reach nearly to the centre. The part making the star-shaped cut is 

 formed from a separate piece of steel so attached to the handle as to make a 

 close joint with the blade. The dotted lines shown at C indicate how the 

 tool is used. The edge of the tarred felt paper should first be cut' by using 

 one edge of the tool. By thus placing the tool where the dotted lines are 

 shown and striking the handle with a hammer, or wooden mallet, a complete 

 hexagonal disc is cut out similar to that shown at B. One yard of tarred 

 felt paper is sufficient to make about 200 discs. In small gardens where 

 only a fewdiscswould be required the grower by following the diagram closely 



