The Cabbage Root Maggot. 539 



from laying their eggs." He reports it a failure. In England gas lime is 

 extensively used by gardeners, and Miss Ormerod reports some favorable 

 testimony for it as a preventive ; none of the evidence is conclusive, how- 

 ever. In Canada, Mr. Fletcher reports good effects from putting a small 

 quantity of fresh gas-lime around each Cabbage plant when setting it out ; 

 on radishes or onions it had to be applied at frequent intervals, and was then 

 not an infallible remedy. Mr. Wright Rives, of Washington, D C, writes 

 us that the cabbage growers near Beltsville, .Md., use large quantities of gas 

 lime yearly, and lh»y report good results from it. 



Thus, there is but little definite evidence either for or against the effective- 

 ness of gas lime as a preventive. It cannot be readily obtained in many lo- 

 calities, and is liable to injure ti,e plants if used when too fresh or in too 

 large quantities. Wherever it is practicable it shouldibe tried, although we 

 are inclined to doubt its efficiency. 



2. Cultivation. 



Whatever method is employed in growing the crop seems to have but lit- 

 tle preventive effect on the insect. It is true that often a much larger crop 

 is produced in an infested field if the soil is kept well hilled up around the 

 plant. In this case the difference is not due to the lessening of the numbers 

 of the pest, but the plant, thus encouraged, sends out enough roots for both 

 itself and the maggots. However, we believe that the numbers of the pest 

 can be materially lessened for the next season by following the infested crop 

 with some crop which the pest does not attack. This crop should be one 

 requiring frequent cultivation so as to keep down all Cruciferous weeds.some 

 of which we now know would harbor the pest. Also, if all the remnants of the 

 crops upon which the pest feeds, as the cabbage "stumps," etc., are thor- 

 oughly removed and destroyed in the fall, we believe many of the insects 

 will thus be destroyed. Thus, clean culture throughout the season will, we 

 believe, materially lessen the numbers of the pest appearing next spring, 

 and thus act as a preventive. 



3. Kerosene Oil and Sand. 



In 1S85, Mr. Fletcher reported that he had good success in preventing the 

 attacks of the pest on radishes by sprinkling sand saturated with kerosene 

 (a large cupful to a pailful of dry sand) along the rows once a week until 

 they were large enough to thin out and have the ground well hoed over the 

 roots. He also reports good results from its application every week until the 

 middle of July around the stems of cabbages. This simple method is prac- 

 ticable, on a small scale at least, and should be tried by gardeners, for all the 

 evidence yet reported favors it. 



