RECOMMENDATIONS 

 FOR THE CONTROL OF THE CARROT RUST FLY 



Cultural Practices 



Do not plant carrots in cool, damp areas which attract the flies and favor 

 their development. 



If early carrots are planted, be prepared to use insecticides; if late carrots are 

 planted, sow the seed about June 10 to avoid the attack of the first generation 

 of the carrot rust fly. If the main crop is late carrots, do not plant small blocks of 

 early carrots which may provide favorable breeding places for a large second 

 generation of the pest. 



Do not thin carrots at the height of the oviposition period of the carrot rust 

 fly because this loosens the soil and provides protection to the flies while laying 

 eggs in crevices in the soil. 



Do not leave infested carrots in the ground at harvest. If they are worthless 

 because of carrot rust fly injury, pull them and dispose of the carrots immediately 

 so that the maggots in them will be killed. This may be done by burning with 

 oil, burying with quick lime under a foot of packed soil, or feeding to livestock 

 in the barn. Infested carrots discarded at sorting, or found in storage, should be 

 treated in the same way, and boxes or bins in which infested carrots have been 

 stored should be cleaned or fumigated with carbon disulfide. 



Cultivate or harrow lightly in late autumn to expose larvae and pupae to 

 weather, and plow deeply in spring to turn overwintering insects under the soil. 



Insecticide Treatments 



Treat carrot seed with powdered calomel, mixing l^ pound with each pound 

 of seed just before planting, especially for early carrots. 



On early carrots, if an expense of 5 to 10 cents per bushel is practicable, make 

 three applications of derris or cube-clay dust containing at least 0.6 percent 

 rotenone, at the rate of J^ to J^ pound to each 100 feet of row, at weekly intervals 

 beginning May 25 in early seasons and June 1 in late seasons; or make three 

 applications of naphthalene flakes at the same weekly intervals using 1 pound to 

 each 100 feet of row. 



On late carrots, if an expense of 10 cents per bushel is practicable, make four 

 applications of naphthalene flakes at weekly intervals beginning about August 1 

 and using 1 pound to each 100 feet of row. Ground tobacco containing 1 to 

 1J4 percent nicotine at the rate of 2 pounds to each 100 feet of row, or Scotch 

 soot at the rate of 3 or 4 pounds to each 100 feet of row, can bo used in the same 

 way at a slightly greater cost. 



