The Cabbage Root Maggot, 515 



all of the flies from the second brood of puparia do not emerge the same 

 season. Maggots working in turnips were sent him July 21. These were 

 put, with a turnip root, in a flower-pot ; but the flies did not emerge until 

 the following April. 



The above discussion indicates that the life history of this pest 

 becomes quite complicated in July and August. We are able to 

 definitely trace but two distinct broods of the pest, the second 

 brood changing to puparia in July. 



Hibernation. — Curtis says : " Many of the flies no doubt live 

 through the winter, secreted in holes and crevices, and some of 

 the pupae do not hatch until the spring ; " this is but a free tran- 

 slation of what Bouche wrote in 1834. All later authors agree 

 with Bouche. In 1884, Dr. Riley said that "the insect hiber- 

 nates both in the larva state in the roots and in the puparium 

 state underground." Thus it has come to be the accepted belief 

 that the pest passes the winter in all three of its later stages — the 

 maggot, the puparium and the fly. 



The experience of Mr. Fyles who, on November 21, examined radish roots 

 on which the maggots were operating in October, and found no maggots, 

 would indicate that the pest does not pass the winter as a maggot ; and we 

 are inclined to think that this method of hibernation is exceptional. For, 

 early in April, while searching for the pest on Long Island, we examined 

 many of these "stumps" left in the fall, but saw no indications of hiber- 

 nating maggots. This point could be easily settled by some field observa- 

 tions in the winter or early spring. 



Most observers agree that the usual method of hibernation is in the 

 puparium. This is the form in which we found the insect early in April on 

 Long Island. They were found in the soil around the base of " stumps " of 

 early cabbage. However, but comparatively few were found in this situa- 

 tion, and we had no opportunity to examine the soil where late crops had 

 grown. So few puparia were found that it seemed improbable that the pest 

 would be numerous this season. But, notwithstanding the fact that the 

 cabbage field was removed about 150 feet from last year's field, the maggots 

 were more numerous than ever this season. This would indicate that either 

 the pest bred freely in other late crops thus producing many puparia else- 

 where, or that possibly many flies hibernated. 



The indications, as shown in our discussion of the number of 

 broods of the pest, are that possibly some of the first brood and 

 many of the second brood of puparia hibernate, not giving out 

 their flies until the next April. 



Apparently the only evidence we have of the hibernation of the 

 flies, is the statement of Bouche quoted above. We found but 



