The Cabbage Root Maggot. 505 



might be mistaken by the casual observer for the beginning stage of the 

 Club-root attack. But the gall like stage of the fungus is soon reached, 

 when it should be easily distinguished from the possibly slight swellings 

 with their accompanying maggots. 



In short, the only relation of the Cabbage Root Maggot to the 

 Club-root is that it is often found associated with it, and perhaps 

 feeding upon or even within the gall-like excrescences produced 

 by the Slime Mould. However, the Club-root is a disease entirely 

 distinct from the maggot attack and the maggot is not one of the 

 causes of the disease, for although both sometimes thus occur in 

 intimate connection, they also frequently occur entirely independ- 

 ent of each other, in this case producing effects on the roots that 

 could scarcely be confounded. 



THE UFE-HISTORY OF THE PEST. 



But little has been added to our knowledge of the life-history 

 of the Cabbage Root Maggot since it first became known in the 

 early part of the century. Curtis, Fitch and Fletcher have added 

 a few details regarding the method of oviposition, and habits of 

 the maggots and flies. And yet our observations indicate that 

 there is still much to be learned of the habits and life-history of 

 the pest, especially during the latter part of the summer. 



Our observations on its life-history have been carried on mostly 

 at the insectary. Unfortunately, and much to our surprise, we 

 have had but little success in breeding the insect in our cages. 

 And as our base of operations was so far away (the extreme east- 

 ern end of lyoug Island), but few field observations were practica- 

 ble. However, our investigations have brought out some new 

 and surprising facts which should be supplemented by a careful 

 study of the pest in the field. We believe there are several phases 

 of the insect's life that are not yet understood, which would repay 

 careful investigation. 



lis first appearance and habits in the spring. — No one seems to 

 have recorded any more definite time than early in the spring for 

 the first appearance of this pest for the season. The form in which 

 the pest always appears at this time is that of the adult insect. 

 From whence they come is discussed later under the subject of 

 hibernation. Of course, the date of the appearance of the flies in 



