178 INSPXTS INJURIOUS TO VEGETABLES 



permanently established in New Brunswick, Ontario and Que- 

 bec, Canada, besides occuring in New York and New Hamp- 

 shire. 



The life history of the carrot fly has not been entirely worked 

 out. In the United States, it will probably be found to pass 

 the winter usually as a puparium, but as larvae work also on 

 carrots in store, the flies develop in winter, hence we have 

 great irregularity in development, making generalization im- 

 possible until observations are made in the field. 



The insect develops rather early in the season and both 

 flies and maggots are found throughout the warmer months, 

 but the latter desert the roots for pupation in the earth, the 

 last generation probably descending much deeper than the 

 earlier ones. Curtis states that the summer generations develop 

 in three or four weeks. There are at least two, and probably 

 more, generations annually. Miss Ormerod has observed that 

 the female fly goes down into the ground where she can find 

 a crack or other opening about the roots of the plant affected. 

 Here she lays her eggs, and the maggots, when hatched, work 

 their way into the root; when this is quite small they often 

 destroy the lower portion. 



METHODS OF CONTROL 



The carrot rust fly is difficult to reach with insecticides. Our 

 principal dependence is based upon methods of tillage which 

 will avert attack. 



Kerosene eiiiiilsioii in the proportion of one part to ten of 

 water sprayed upon the carrots along the rows, or sand, or 

 ashes, with which kerosene is mixed at the rate of half a pint 

 to three gallons, sprinkled along the rows, have given good 

 results. These substances deter the fly from laying her eggs. 



Late solving and rotation of crops are excellent remedies, 

 as is also the planting of new beds as far as possible from 

 land infested the previous season. 



