Prevention of Egg-laying 



The most frequently used of these substances is 

 paraffin. It is used in three ways. (1) As an 

 emulsion for sprajdng chrysanthemums, marguerites, 

 and celery against the marguerite and celery flies 

 respectively. The emulsion must be used at 

 summer strength and appUed from March onwards 

 to the former and May onwards to the latter plants. 

 (2) For damping sand or sawdust to sprinkle along 

 the rows of seedling cabbages, cauliflowers, and 

 similar plants, and onions, to deter the respective 

 flies [cabbage root fly (see below) and onion fly] 

 from visiting the plants, beginning in May or 

 earlier in very early districts, and repeating at 

 ten-day intervals. (3) For the same purpose 

 where the onion fly is concerned, strings carrying at 

 intervals pieces of rag may be stretched above the 

 onion bed and the rags damped by dipping in a jar 

 of paraffin once every fortnight from early May 

 onwards. The same measure might be tried with 

 the carnation fly, and possibly the narcissus fly. 



Naphthalene (often called " carbon ") is used to 

 sprinkle on clothes to prevent the clothes moth 

 from laying its eggs, and camphor has the same 

 effect. Crude naphthalene is the basis of several 

 proprietary articles that are used to drive insects 

 from plants and are known as soil-fumigants and 

 recommended as means of guarding plants from the 

 attacks of wireworms, etc. When camphor again 

 becomes lower in price camphor water sprayed or 



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