66 Belladonna Leaf-Miner 



applied in the spring, immediately previous to the sowing of the seed. 

 Autumn manuring, as soon after the harvest as possible, is therefore 

 advised, a course which Jablonowski (1909) also recommended in the 

 cultivation of the beet. The manure is thus given a chance to decay and 

 sink well into the soil during the winter months with the result that 

 the fly is not attracted by it to the same extent as it would be by 

 fresh dung. 



The greatest and most lasting damage is usually committed by the 

 mangold maggot at the seedling stages of the plants soon after thej^ have 

 been singled out. Thus a system of manuring which forces on the 

 growth of the crop beyond this susceptible period, proves of much 

 advantage in staving ofE ultimate disaster. To accomplish this Miss 

 Ormerod found that the application of sodium nitrate in the proportion 

 of about • two-hundredweight to the acre produced desirable results. 

 The only drawback is that, unless there be sufficient rain to wash the 

 fertiliser down to the roots, its value as a stimulating agent is vastly 

 reduced and almost negligible. Dressings of salt, potash and super- 

 phosphate introduced to the soil along with the seed have often proved 

 beneficial. Where clean culture is practised and where the crop is 

 grown in situations favourable to growth the loss incurred from the 

 ravages of the maggot is not very appreciable. When neglected, the 

 crop simply perishes from exhaustion in consequence of the leaves being 

 killed off by the maggots more rapidly than the plant can replace them. 



Spraying the infected crops with paraffin emulsion is another method 

 which was brought to Miss Ormerod's notice (1885, p. 68) as an efficient 

 remedy. The insecticide is made up in the proportions of 8 parts of 

 water to 1 part of soft soap with 4| parts of paraffin added to the first 

 two of these ingredients which have been previously mixed and boiled. 

 A homogeneous mixture is thus obtained, and 1 part of the emulsion 

 combined with 4 parts of water is said to prove quite effective in 

 killing off the maggot. 



Theobald also deals with the occurrence of the fly in this country 

 in his reports 1909-11, and the same methods of combatting its attacks 

 are reconmiended as those given by Miss Ormerod. This author also 

 states that deep ploughing after an attack of the maggot will bury the 

 puparia in the soil, thus rendering the emergence of the fly to the surface 

 a difficult one. V»\\t I should imagine that where the soil is inclined to 

 be heavy, forming clods instead of a fine tilth, the adults will generally 

 succeed in making their way up, so that this method would only prove 

 of utility in the case of light soils. 



