Apr. 15, 1914 
Corn-Leaf Blotch Miner 
17 
in 1911. From the appearance of the mines and pupa the host was 
probably A. parvicornis. He also reared adults of this miner from com 
at Montgomery, Ala., in 1911 and at Lakeland, Fla., in 1912. 
Mr. T. H. Parks, recently of the Bureau of Entomology, observed the 
work of a leaf-miner on sweet com at Wellington, Kans., in 1909. While 
nothing but parasites was reared, the character of the mine indicates that 
it was probably the work of Agromyza parvicornis. 
This species was again found at Richmond, Ind., but sparingly, in 
1909, 1910, and 1911. In October, 1911, it was found infesting broom 
or hog millet (Panicum miliaceum) at La Fayette, Ind., and in 1912 it 
was very abundant in com and several of the grasses on the experiment 
station grounds at La Fayette. In fact, it could be readily found in any 
cornfield in that locality. 
Mr. J. J. Davis, of the Bureau of Entomology, found it at Lancaster, 
Wis., mining in com leaves, and at Danville, Ill., in the leaves of Echino- 
chloa crus-galli , in July, 
1912. Mr.C. N. Ainslie 
reared the same miner 
from com at Salt Lake 
City, Utah, in 1912; 
and Mr. W. L. McAtee, 
of the Biological Sur¬ 
vey, collected it at Bilt- 
more, N. C., the same 
year. It appears to 
have been more abun¬ 
dant in 1912 than dur¬ 
ing any of the other 
years, and naturally 
more species of parasites were reared at that time than from all previous 
rearings. Mr. Davis also found the work of what is probably this species 
near Louisville, Ky., in July, 1913. 
DISTRIBUTION OF THE CORN-LEAF BLOTCH MINER 
From the foregoing it will be seen that this leaf-miner has quite a wide 
range, being found as far north as Wisconsin, as far east as Washington, 
D. C., and New England, as far south as Alabama and Florida, and as 
far west as Salt Lake City, Utah, as well as in Texas: It probably occurs 
throughout the United States wherever corn is grown. The known dis¬ 
tribution is shown on the map (fig. 1). 
HOST PLANTS 
There does not seem to be a great variety of host plants, Agromyza par¬ 
vicornis having apparently thus far confined itself to a few species of the 
Gramineae. The species seems to show a preference for com, especially 
36132 14-2 
Fig. i.— Map of the United States, showing distribution of Agromyza 
parvicornis , the corn-leaf blotch miner. (Original.) 
