U. S. D. A., B. E. Bui. 66, Part I. tamed March 16, 1907. 
SOME INSECTS INJURIOUS TO TRUCK CROPS. 
THE ASPARAGUS MINER. 
(Agromyza simplex Loew. I 
By F. II. Chittenden, 
Entomologist in Charge of Breeding Experiments. 
The stalks of asparagus are frequently attacked by insects, and in 
recent years have been reported considerably injured by the larva or 
maggot of a minute black fly to which the name asparagus miner has 
been given. The larva mines under the epidermis of the stalk, and 
when it has transformed to the puparium or "flaxseed" stage the thin 
outer skin becomes more or less ruptured and the presence of the 
insect is easil} T detected. It operates more abundantly near the base 
of the stalks and penetrates below r the surface of the ground to a 
depth of 7 or 8 inches. During the year 1906 this species attracted 
considerable attention by its abundance in some of the principal 
asparagus-growing sections of New England and it bids fair to become 
a pest of considerable importance. It was first noticed on asparagus 
Fig. 1.— Agromyza simplex: Fly, dorsal view at left, lateral view at right. Highly magnified 
(original). 
in 1896, ten years earlier than the present writing, prior to which 
time nothing was known of its habits. It is a native species and evi- 
dently restricted to asparagus as a food plant. Until the year L906 
it had not been recognized as doing injury to cutting beds, although 
attack had been observed in various sections. The mines of the larvae 
about and below the bases of the stalks are frequently so abundant 
that they have the effect of girdling, so that the injured stalks can be 
readily pulled from the ground. 
DESCRIPTIVE. 
The parent insect is a two- winged fly (tig. 1), metallic black, with 
large prominent head and eyes, and clear wings, the wing expanse 
being about one sixth o( an inch (1 nun.). 
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