CONTROL OF CABBAGE MAGGOT ON EAELY 



CABBAGE.* 



F. H. HALL. 



Any pest which attacks the roots of plants 



Cabbage maggot mus t be considered a dangerous enemy. The 

 injuries serious. . . . , ,. , .. , . 



injury involves the parts most essential to 



the life of plants; and the pest itself is liable to be so hidden 



from view that its presence will become known only when the 



effects of its work appear, which is frequently too late for effective 



control. The concealment in the soil, also, and the protective 



influence of this cover make repressive measures very difficult 



and uncertain. For these reasons, control of the cabbage maggot 



has long been a problem for entomologists. In the growing of late 



cabbage, however, the insect is not to be feared in the field, since 



its ravages for the season are over before the plants are set ; and 



the practice of screening seed beds (discussed in Bulletins 301 and 



334 of this Station) makes it possible to secure, at only slight 



expense, healthy, uninjured, vigorous plants to set. 



Upon early cabbage, on the contrary, the cab- 



u£ n G ^ ^age maggot is a field pest ; and its injuries 

 cabbage. . 1 11 1 



are sometimes so severe as to destroy all nope 



of profit from the crop. In order to secure the best prices for 



early cabbage, the heads should be ready for market in July; 



and this means that the plants must be set in the field — from 



greenhouses or cold frames — in late April or early May. Shortly 



after this time (May 20 to June 5) the cabbage maggot flies 



* Reprint of Popular Edition of Bulletin No. 382; for Bulletin see p. 405. 



[92G] 



