54 FLIES. 



only live on various kinds of plant roots, but also in 

 dung ; and the question therefore comes whether the 

 use of animal manure in a state, and at the time, 

 when it may bring maggots with it to the coming crop, 

 is desirable. We need plenty of good strong manure 

 if the crops are to grow, but still there are different 

 ways of treating it before application, and different 

 times of applying it. 



The great German authority on Flies, Dr. Rudolph 

 Schiner, says of the division of Antliomyia, to which 

 the Beet Flies, Onion Flies, and Cabbage Flies belong, 

 that in many cases the larvffi live in vegetable sub- 

 stances, and also that many seek out rotting and 

 putrefying matter. 



It has been found that the "Root-eating" Flies, 

 the Antliomyia radicum (Fig. 46, 4), of which the 

 maggots feed on Cabbage and Turnip roots, inhabit 

 dung by thousands, and especially frequent night- 

 soil ; also that they attack crops manured with horse- 

 dung and bone-dust, whilst on ground close by 

 plants manured with superphosphate are not at all 

 attacked. 



Another kind of Cabbage-root maggot, that of the 

 A.Jioralis, was found by myself in earth round partly 

 decayed Clover-roots. 



The spiny maggots of the Antliomyia tuherosa, the 

 Potato Fl}^ as it was named by John Curtis (figured 

 with the perfect Fly, at p. 53), have been found 

 swarming in rotten Potatoes, and also, as well 

 as their chrj'salids, in ground often occupied by 

 Cabbage. 



The maggots of the Shallot Fly {A. ^jJatnra) have 

 been found in great numbers in night-soil ; and I 

 have a note of attack of Onion maggot having showed 

 itself in the greatest numbers where cow manure had 

 laid for a considerable time before being dug in. All 

 the plants, where, or near to where, the heaps had 

 been, were destroyed by the 1st of July. 



From these notes it would appear that, whether 



