84 MANGOLD. 



Mangold leaves were large enough to accommodate a fair sized blister, 

 and dm-ing the period named, enquiries were sent on most days, and 

 sometimes several in the course of one day. From the 20th of June 

 onwards, there was little if any further enquiry about this infestation 

 until nearly the end of July, and again towards the end of August, 

 when some amount of further communication occurred regarding its 

 appearance in the large leafage of the plants, then well advanced in 

 growth. 



Looking at the amount of attack running so far west as Devon, and 

 the neighbourhood of Truro, in Cornwall, it is of some interest to notice 

 its absence in Tresco, Isles of Scilly. Early in August, Mr. Winfield, 

 writing on the part of Mr. Smith, consulted me as to another kind of 

 injury then occurring to Mangolds, and I took the opportunity to make 

 special inquiry as to presence of the Leaf Maggot, the larva of the 

 Anthoviyia betce. 



On the 3rd of September, Mr. Winfield replied that he had noticed 

 the accounts in the papers, and was on the look-out for it, but he was 

 glad to say that it had not made its appearance there. 



Although this Mangold-leaf Maggot occurs more or less every year, 

 and sometimes very badly, it is still so often not recognised, that I 

 have now added (page 83) a figure which shows the method of injury 

 to the leaf. Not being able at present to give a figure of the Mangold 

 leaf itself in its infested state, I have substituted one of a Celery leaf, 

 which, though injured by another kind of fly-maggot, yet gives an 

 excellent idea of the way in which the Mangold leaves are blistered, so 

 that the upper and under skin are separated in patches, and the films 

 to which they are reduced at times become so transparent that the 

 shape of the maggots feeding within can be seen. For the most part, 

 however, the patches merely show as white blisters a little raised in 

 places where the maggots are lying within, or (further on in the 

 attack) these destroyed parts turn brown or discoloured, as if bitten by 

 frost, to which not unfrequently the injury (till investigated), is 

 attributed. 



The maggots of the Mangold Fly (which at life size are almost or 

 wholly indistinguishable from that figured in the leaf) are whitish or 

 greenish, fleshy, cylindrical, legless, truncate or blunt at the tail, and 

 pointed towards the head end, which contains two black hooks within 

 it, wherewith the maggot scrapes away the soft substance between the 

 two sides of the leaf on which it feeds. According to its age it may be 

 smaller, or a little larger than the larva of the Parsnip and Celery 

 Leaf-miner Fly figured. 



The maggot usually quits the leaf-blister when full-fed, and turns 

 to a chestnut-brown chrysalis in the ground. Sometimes, however, 

 the change takes place in the leaf-blisters. It is of the shape figured, 



