192 INSECTS AFFECTING THE CABBAGE. 



but since the introduction of the alien species they 

 have been largely crowded to the wall, and are sel- 

 dom destructive. 



Remedies. — Pyrethrurn (insect powder or bu- 

 bach), hot water, and kerosene emulsion are the sub- 

 stances that can most successfully be used in fighting 

 the Imported Cabbage Worm. The insect powder 

 may be diluted with six or eight times its bulk of 

 flour, and dusted on with a powder-gun or bellows, 

 or it may be mixed with water in the proportion of 

 one ounce to four or five gallons of water, and sprayed 

 upon the plants. Dr. Riley gives preference to hot 

 water as a remedy for this insect. He states that 

 " every worm visible upon the cabbages may be 

 killed by the use of hot water at the temperature of 

 130° Fahrenheit. The water may be boiling hot 

 when put in the watering-can, but it will not be too 

 hot when it reaches the cabbage leaves." Kerosene 

 emulsion can advantageously be used when the 

 plants are young, though there would appear to be 

 danger of tainting the heads if applied to the fully 

 developed plants. Whichever method of treatment 

 is adopted, it should be carried into practice at fre- 

 quent intervals, thus keeping the worms well in 

 check. If the plants are dusted with insect powder 

 once a week during the time that the worms are 

 present, they will cause little or no trouble. For 

 applying the water mixtures of pyrethrurn, or kero- 

 sene emulsion, either the Excelsior or Field knapsack 

 sprayers appear to be well adapted ; while on a larger 

 scale the Nixon potato sprayer might be utilized. 



