The Cabbage Root Maggot. 543 



plied to another plant on which 100 small maggots had been placed. The 

 next day a superficial examination showed that many of the maggots were 

 dying. June 8, 32 live puparia were found in the cage where the i to 9 part 

 dilution had been used ; and 40 puparia in the other cage. As from 71 to 

 95 puparia were found in similar cages receiving no treatment, it is evident 

 that the emulsion killed many of the maggots. 



The evidence would seem to support the conclusion that the kerosene 

 emulsion (using 2 gallons kerosene, i gallon water, and one-half pound soap) 

 diluted with 12 parts of water, will prove quite effective if applied early and 

 often to radishes and onions, and two or three times on cabbages and cauli- 

 flowers. It must be applied thoroughly, by first removing some of the earth 

 from around the base of the plant and either syringing in the liquid or applying 

 through a knapsack sprayer. It will prove practicable on a small scale, at 

 least. We believe, however, that the carbolic acid emulsion or the carbon 

 bisulphide treatment previously discussed, will prove more effective and prac- 

 ticable. 



2. Destruction of the Pupae. 



{a) By Destroying old '^^ Stumps " in the Fall. 



Some authors have recommended the removal and destruction of the old 

 "stumps" usually left in the field in the fall, in order that the puparia 

 which they may contain be thus destroyed. We doubt if there are ever 

 many paparia in these old " stumps" in the fall, but some maggots may 

 thus be destroyed. Doubtless more of the insects would be destroyed by the 

 destruction of the ' ' stumps ' ' of the early crop as soon as the crop is gathered. 

 In any case the old " stumps" should always be removed, for although they 

 may not contain many specimens of this pest, they furnish breeding places 

 and shelter for other noxious insects. 



{b) By Fall Plowing. 



Kiinstler, in 1871, suggested that many of the hibernating puparia might 

 be destroyed by plowing the ground late in the fall. Messrs. Riley, I/int- 

 ner and Fletcher have also recommended it. Doubtless a late plowing 

 followed by a thorough harrowing would destroy or deeply bury some of the 

 puparia and thus help to check the pest. 



{c) By Use oj Gas Lime. 



Dr. Lintner, in 1885, suggested that a heavy dressing of gas lime applied 

 in the fall, would doubtless kill many of the hibernating puparia. It might. 



3. INEFFECTIVE, OR IMPRACTICABLE METHODS. 



Under this heading are grouped those methods which have been 

 thoroughly tested and found ineffective or impracticable ; and 

 some methods are also included which have not been sufi&ciently 



