lU iioUGnroN, ON Tiiii; mamjold-wlrzkl fly. 



uiul Beet/ and at p. 411, he has described the male of a 

 species of Anthomyia, which lie appropriately calls Amthomyia 

 betcp.. ]Mr. Curtis states that his acquaiutance with this Hy 

 was made from a communication sent him by a gentleman of 

 Crawford, and that he was indeljted to him for the history of 

 its economy. '' The maggots were brought to me from 

 Surrey, on the 26th of June, found feedingbetweeu the skins of 

 the leaves, the integuments of which they cut rapidly, giving 

 the plants attacked a blistered appearance. They were of a 

 greenish colour, a quarter of an inch long, pointed at the 

 head, and rather abruptly cut off at the tail, they turned to 

 pupae in situ, as you may see by the fragments of the leaves, 

 and hatched July ITtli and 20th;" it may be added that the 

 plant whence the insects w^ere olitained had been destroyed 

 by their attacks, and that the sugar-beet had also suffered 

 from the same cause. 



This account, so far as I have been able to ascertain, con- 

 tains the earliest and only information as to the " fons et 

 origo mali,'^ Avhich during the last year has seriously injured 

 the mangold crops ; for that the same insect, which was de- 

 scribed by Curtis in 1847, is identical with that wdiich 

 attacked the crops last year I am in a position to show, as 

 also to figure and describe the female fly, which appears 

 hitherto never to have been recognised, " the males only," 

 writes Mr. Curtis, "being known at present" (1847). My 

 attention was naturally called to this subject in the summer 

 of last year, by the sickly appearance of the mangolds, w^hole 

 fields in this neighbourhood presenting an appearance as if 

 the leaves of the plants had suffered from some scorching 

 influence. With a A'iew to ascertain the origin of the evil, I 

 paid frequent visits to a mangold field, in order to discover 

 the fly which was the parent of the leaf-mining larvae, whose 

 existence within the cuticles an intelligent farmer in the 

 parish had first pointed out to me. I searched hundreds of 

 leaves, in order to obtain possession of some pupa3, but in 

 vain. I brought home several leaves containing full-grown 

 larvse, which I anticipated would soon become pupse, and 

 placed them in water, in hopes of thus being able to 

 secure a pupa or two ; but I found that the larvoe always 

 dropped out of the leaves. Failing in this, I determined to 

 watch the insects in the field, and my suspicions were soon 

 fixed upon a two-winged fly with reddish-brown eyes, Avhich 

 was very abundant on the mangold leaves, and seemed 

 evidently to have some object in view beyond the mere 

 ordinary and incidental one of settling upon them. At this 

 time I knew nothing of what Mr. Curtis had published on 

 the subject. I observed on the under surface of the leaves a 



