A. E. Cameron 



<)7 



In carrying out experiments with the maggot which mines in the 

 leaves of the belUidonna, I found that an emulsion consisting of nicotine, 

 paraffin and soft soap with water woukl at least check virulent attacks, 

 and, if applied to the plants early in the season, it proved an excellent 

 preventive against the fiy ovipositing. The fully developed larvae 

 did not seem to experience much inconvenience from contact with the 

 insecticide, which is prepared as follows : to four parts of soft soap 

 two pints of paraffin are added, and the mixture brought to the boiling 



Fig. 3. Belladona plant used in breeding experiments of Peyomyia liyoscyami. 

 Appearance after attack. 



point. A small quantity of boiling water is then stirred in, and the 

 whole then well mixed until a good emulsion is obtained. Four ounces 

 of 95 % pure nicotine are then added. After thoroughly mixing the 

 volume is increased to 100 gallons by the addition of more water. If 

 poured into a drum and kept well corked the mixture can be stored and 

 used at any time. The insecticide should be administered as a fine 

 spray by means of a nozzle of the improved Vermorel or other makes, 

 care being taken that both the upper and under surfaces of the leaves 



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