The Cabbage Root Maggot. 541 



injury is the underground portion of the stem above the mass of roots. If 

 about two inches of the soil be removed that part of the stem most attacked 

 is laid bare, but the roots need not be disturbed. An important thing is not 

 to put off the treatment too long." In 1892, andin iS93,he reports this helle- 

 bore tea in a large measure successful, but concludes that it is practicable 

 only in gardens and not for field practice. 



Although others have since recommended this hellebore tea, yet no one 

 except Prof. J. B. Smith seems to have tested it. In 1892, Prof Smith had 

 one of his correspondents test it on the cabbage maggots, using on each plant 

 one-half pint of the tea, containing one ounce of hellebore in one gallon of 

 water; it was reported a success. However, he says: "As against the 

 Onion Maggot, I scarcely know whether to recommend it as yet, without 

 further experiment." 



May 25, we put roo small maggots about the base of a well-established cab- 

 bage plant. The next day when the maggots had begun work on the root, 

 we poured 4 ounces of hellebore tea (i ounce steeped in i gallon of water) 

 in a cavity about the plant. Four daj's later, we found live maggots working 

 on the stem near the surface ; and June 7, 68 live puparia (and one maggot 

 still feeding on the stem) were found in the cage. As only 71 puparia were 

 found in a similar cage not treated, it was evident that our application had 

 had but little effect on the maggots. In another similar cage the decoction 

 had no effect on mature maggots and recently formed puparia. The helle- 

 bore used was practically fresh, as it had been kept in air-tight jars. 



In the face of such positive results attained by so careful an investigator as 

 Mr. Fletcher, it would not be fair to conclude from our slight experience that 

 this hellebore tea is not an effective killing agent when used againt these 

 root maggots. And yet our experiment shows that there is need of further 

 experimentation with the substance before it can be confidently recom- 

 mended for indiscrimate use by gardeners. This simple remedial measure 

 should be thoroughly tested by other investigators. 



Kerosene Emulsion. 



The first experiments we find recorded with a kerosene emulsion were 

 made by Prof. Cook in 1884. He dissolved i qt. soft soap in i gal. hot water 

 and then added i pint of kerosene oil. It was reported ' ' a safe and very 

 efficient specific against these very destructive maggots." He devised an 

 instrument for applying it below the surface of the soil (Figured in Rept. 

 Mich. Hort. Soc. for 1884, p. 204). Two years later, Prof Cook treated rad- 

 ishes with a similar, but stronger, emulsion (i lb. soap, i gal. water, 2 qts. 

 kerosene) diluted with about 2 parts of water. Treatment was begun when 

 the plants were small and continued every three or four days for 4 weeks ; 

 a tablespoonful was applied to each plant each time, and three-fourths of the 

 plants were entirely free from the maggots. He concluded from his experi- 

 ments thus far that, when made by the first formula, the emulsion was sure 

 death to the maggots but must be applied early and often ; he then preferred 



