504 



Bulletin 78. 



where there are no maggots. Thus the Club-root of cabbage is a 

 disease of ilself entirely distinct from the work of the Cabbage 

 Root Maggot or any other insect. 



However, it still seems to be the general belief among American entomolo- 

 gists that either "there can be but little doubt but that the work of these 

 larvae (Cabbage Root Maggots) is one of the several cause'? of ' Club- root ' of 



Fig 7. — "■ Club-rooted^'' Cabbages ; about '4 natural size. 



cabbage," as Dr. Riley said in 1884 ; or that " they sometimes cause the roots 

 to thicken up and become malformed, producing an effect similar to ihat of 

 the fungus causing the disease known as 'Club root,' ' says Weed in his 

 " Insects and Insecticides." Our observations of the work and habits of the 

 maggots in the tield and in the insectary lead us to believe with Miss Orme- 

 rod (Rept. for 1892, p. 143) that the maggots " bore into the roots and cause 

 mischief, sometimes to a very serious extent, by the decay thus originated, 

 as well as by Iheir destructive gnawings ; but they do not cause gall growths, 

 nor do they cause the diseased, enlarged growth which we see in the case of 

 ' Finger-and-Toe," or 'Club.' * * * (p. 159). The Club is entirely and 

 absolutely distinct in its nature from any insect attack." True, as the same 

 author says, the cabbage stalk or turnip root may swell slightly and often 

 become putrid from the attacks of the maggots, and under these condi ions 



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