420 The Profitable Culture of Vegetables. 



CABBAGE AND TURNIP ROOT GALL WEEVIL (Ceutorhynchus 

 sulcicollis). These weevils lay their eggs in holes which they make in 

 the root or at the base of the stems of cabbages and other brassicse. The 

 irritation thus set up causes small lumps or swellings to form which are 

 known as " galls." If these are cut open the grubs of the weevil will be 

 found in the cavity they have eaten out. 



Treatment : Rotation of crops ; avoid planting any members of the 

 brassica tribe on affected soil. Burn all infested roots. 



Dig gas-lime or one of the soil fumigants into beds which have produced 

 infested plants. 



CARROT FLY (Psila rosce). The Carrot Fly is shiny black or dark 

 green in colour, about the fifth of an inch long, with a wing expanse of 

 nearly half an inch. When the carrots are well established the flies lay 

 eggs upon them just below the ground. The maggot is without legs, of a 

 yellowish colour and almost transparent, and nearly a quarter of an inch 

 long. It has no distinct head, but its fore-end tapers to a point ; the hind- 

 end is blunt. As soon as the maggot is hatched out it goes down and bores 



holes in the lower part 

 of the root, then tunnels 

 upwards, with frequent 

 holes to the outside. The 

 effect upon the roots is 

 to cause them to become 

 brown or "rusty" and 

 finally rotten. An attack 

 is indicated by the outer 

 leaves going yellow and 

 withered ; when such are 

 observed the roots should 

 Carrot Fly and Maggot. be carefully forked up so 



1 and 2, Affected Root, showing "rust" spots and Maggots that no part is left in the 

 protruding; 4 and 6, Maggots; 7 and 8, Pupa; 9 and 11, ground, and destroyed. 

 Fly each natural size and magnified. 



lr the flies are observed 



on or near the carrot plants these should be at once sprayed with paraffin 

 emulsion ; or sawdust, sand, or ashes impregnated with paraffin or carbolic 

 acid may be scattered over the bed and will serve to repel the flies. 



Carrots grown early for bunching are seldom injured by the fly, which 

 does not, as a rule attack them until after the end of May. It is considered 

 that the loosening of the soil about the roots caused by thinning and 

 singling the plants offers inducements to the fly to deposit its eggs there ; 

 to guard against this the plants should be thinned early, and as part of the 

 work is completed the earth should be drawn close around the stems and 

 trodden tightly in on both sides of the row. Heavy watering immediately 

 afterwards tends to further consolidate the soil and ward off attack, besides 

 helping the growth of the carrots. In a district where the fly is common, 

 spraying with paraffin emulsion should follow. 



