24 



Control. — Very little can be done after the plants are at- 

 tacked, except to cut out the borers and cover the infested 

 stems with dirt, thus encouraging the formation of secondary 

 roots. Harrow the fields during the fall and plow deeply in 

 the spring to prevent the moths from emerging from their 

 cells in the ground. 



Attacking Onions. 



1. Cutworms (see page 9). 



2. Wireworms (see page 10). 



3. Plant bugs (see page 13). 



4. Onion thrips (see page 11). 



5. Imported onion maggot, Chortophila (Pegomya) cepetorum 

 Meade. 



This common white maggot, which bores into the roots and 

 bulbs, causing them to wilt and decay, is probably the most 

 important pest of the onion. These maggots are the offspring 

 of small flies which are very similar to the adults of the cabbage 

 root maggot. The eggs are laid on the young plants early in 

 the spring, and the tiny maggots soon appear and bore into 

 the bulb. When full grown they enter the soil, change to 

 pupse and later emerge as adult flies. These deposit eggs for 

 the succeeding generation. Onions are liable to infestation at 

 any time during the growing season, but usually the most 

 serious damage occurs during June, when the plants are young. 



Control. — Liberal application of commercial fertilizers, such 

 as nitrate of soda, which will promote rapid growth, is of great 

 value in overcoming injury by all root-feeding pests. 



A method which proves successful in reducing maggot injury 

 in small gardens consists of watering susceptible plants at 

 weekly intervals, from ^lay 10 to the middle or latter part of 

 June, with carbolic acid emulsion. This emulsion is made as 

 follows: — 



Hard soap, 1 pound. 



Boiling water, 1 gallon. 



Crude carbolic acid, 1 pint. 



Dissolve the soap in boiling water, add the carbolic acid 

 and churn thoroughly with a bucket pump. This stock solu- 



