The Mangel Wurzel Fly. (Anthomyia beta. Curtis.) 



(PLATE II., Fig. 3.) 



Many notes were received in the first week oi June from various 

 parts of the country, of much harm caused to mangel wurzel 

 plants by the larvae, or maggots, of this fly, and the agricultural 

 journals from time to time during the summer recorded 

 accounts of the injury occasioned by them. In some cases the 

 plants were killed by the action of the maggots upon the leaves. 

 In others their growth was retarded and the crop was con- 

 sequently diminished. 



A field of mangels, ten acres in extent, was inspected on the 

 8th of June, and it was found that 65 per cent, at least of the 

 plants had eggs and maggots of the fly upon them. Some of the 

 leaves were brown, and it seemed as if the greater part of them 

 would be destroyed. Upon examination from 5 to 15 maggots 

 were discovered in many of the leaves, whose surfaces were 

 blotched, or blistered. They were within the tissues of the leaves, 

 in which they had made long mines, or passages, and upon which 

 they were feeding, exhausting their juices and extracting the 

 chlorophyll, or green colouring. There were also quantities of 

 eggs upon a great number of the leaves, from which maggots 

 were being constantly hatched. As the land was full of manure, 

 and nitrate of soda was added soon after the presence of the 

 insects was discovered, the plants grew 8 way from them even- 

 ually and yielded a good crop of roots, but their traces were 

 plainly visible throughout the summer, and the crop was reduced. 

 Fine growing showers also helped the plants considerably. If 

 the land had been poor and the weather diy, it is believed that 

 the plants could not have got over the attack. 



This is not by any means a new mangel wurzel pest. Curtis 

 describes the male, and mentions this insect a,s affecting the crop 

 in 1847.* The first serious mischief resulting from this fly was in 

 1876. Again in 1880 much harm was done by it. Also in 1881) 

 there were complaints of serious losses from its action in 

 many counties. 



DESCRIPTION AND LIFE HISTORY. 



The fly belongs to the family Muscidcv. It is about the size 

 of a common house fly which it resembles in appearance. In 

 colour it is grey of a somewhat ashy shade. The legs of the 



* Journal of the Royal Agricultural Society of England, Vol. viii., 1 ser., p. 413, 



