381 
evident. Mr. Koebele reared another generation in June. The follow- 
ing year the company forwarded specimens to Dr. Riley in September, 
which were nearly all in the pupa state and from which flies issued 
September 8. In October of the following year (1893) Mr. J. W. Morse, 
of the Western Beet Sugar Company, sent from Watsonville, Oal., 
three beet roots, accompanied by considerable soil, and in this soil were 
found puparia of the Pegomyia from which, however, no adults issued. 
There seem, therefore, in California, to be at least five annual genera- 
tions, but we are unable to state definitely the method of hibernation. 
Judging from the habits of allied species the insect will hibernate in 
the puparium stage. 
Remedies. — There is little which can be done in the way of direct 
remedies for this insect without sacrificing the foliage, but the foliage 
is not important to the beet crop after a certain time. After the tubers 
become well grown it will be obviously practical and quite efficient as 
a preventive of damage the following year to cut, remove, and destroy 
the beet tops. There will, of course, at any season of the year be a 
greater or less number of puparia in the ground about the roots but 
the numbers of the insect can be greatly reduced by this means. If 
this plan be adopted and if the field be plowed and harrowed after the 
roots are dug, the probabilities are that no serious damage will follow 
next season. 
TWO DIPTEROUS LEAF-MINERS ON GARDEN VEGETABLES. 
By D. W. Coquillett. 
A LEAF-MINER ON RADISHES. 
A new injurious insect has made its appearance in this country 
within the past few years in the shape of a small, two-winged fly, whose 
larva? form rather large blotch mines in the leaves of the garden radish. 
It was first observed on June 12, 1892, by Mr. Theodore Pergande, of 
this division. In one of the gardens of Ivy City, D. C, he noticed 
that quite a large number of the radish leaves had been mined by the 
larva? of a dipterous insect; the greater number of the mines were 
empty, but a few of them still contained larva?, three of which pupated 
the next day, and the adults emerged eight days later. One of these 
is represented in the accompanying illustration (Fig. 40). The color is 
a pale yellowish, with the antenna! arista, an ocellar dot. the tip of the 
abdomen and of each tarsus blackish. 
A recent study of these specimens indicates that they belong to 
Drosophila flaveola Meigen, a rather common European insect, not 
hitherto reported as occurring in this country, in Europe it has been 
bred from larva? found mining the leaves of turnips, pease, Cochlearia 
officinalis, Anthyllis vulneraria. and Tropceolum canariense. As many 
