THE ONION FAMILY 127 



bulb itself is found on examination to be undeveloped, 

 badly shaped, and crowded with dirty white maggots, 

 which feed on it and cause it to become rotten. Some- 

 times, the outer leaves fall to the ground whilst the inner 

 ones are soft and flabby. 



The Board of Agriculture writes as follows with 

 respect to this fly : 



" (1) Spraying onion plants with offensive compositions 

 is a good way of preventing infestation. Paraffin emulsion 

 is as good a compound as any for this purpose. It may be 

 made by thoroughly mixing together three pints of paraffin 

 and a half-pound of soft soap with a gallon of boiling water. 

 This should be applied early in the season when the onions 

 are quite small. Spraying should be repeated twice or 

 thrice, especially if heavy showers fall after the process. 



" (2) Another preventive measure is to mix sand with a 

 little paraffin and place it at the base of the onion plants or 

 work it into the soil. 



" (3) Sprinkling the onions with soot may be adopted with 

 advantage where the seeds are sown broadcast. 



" (4) Where the seed is sown in drills or shallow trenches 

 egg-laying may be prevented by earthing up the neck of the 

 onion plant. 



" (5) When onion plants are noticed to droop and wither, 

 all such plants should be taken up and burned, or placed in 

 quick-lime. 



" (6) Wherever it is possible, onions should not be grown 

 again, for at least one season, on land where this crop has 

 been infested, as the puparia remain in the ground during 

 the winter. All fragments of bulbs should be removed from 

 infested land, as the larva occasionally pupate in the bulbs." 



Of the Onion Mildew the Board states that 



" The first sign of the disease is the appearance of small, 

 scattered, yellowish patches on the leaves. These patches 



