66 
Journal of Agricultural Research 
Vol.I.No. i 
Adults and pupae were collected at Boise, Idaho, by Mr. H. T. Osborn, 
of the Bureau of Entomology, August 22, 1911; and from mined leaves of 
alfalfa received from Sarah A. Armstrong, July 3, 1905, from Fort Collins, 
Colo., adult flies of this species developed en route. 
Its distribution extends westward to the Pacific coast, and throughout 
the irrigated sections of Washington, Oregon, and California. In a 
communication dated January 25, 1912, from Mr. Wyatt W. Jones, of 
Redding, Cal., the winter states that his attention has frequently been 
called to a minute leaf-miner in alfalfa, very common in that region during 
August and September. His attempts to rear adults resulted in securing 
only parasites. On May 14, 1912, 
Mr. Jones collected larvae and pupae 
from young alfalfa plants grown from 
seed sown in March of that year. 
Mr. V. L. Wildermuth, who has 
made a careful study of this insect in 
the Imperial Valley of southern Cali¬ 
fornia and in Arizona, finds it very 
generally distributed over the alfalfa¬ 
growing section of the Southwest, 
where its injury to the hay crop is 
probably greatest. It has also been 
swept from alfalfa at Glendale, Cal., 
by Mr. T. D. Urbahns. 
These flies were reared from larvae 
mining alfalfa leaves at Wellington, 
Kans., by the junior author in July, 
1910, and again by Mr. E. O. G. Kelly, 
of the Bureau of Entomology, at the 
same place during the summer of 
1912. While the injury was not 
severe, Mr. Kelly reported plants with 
from 12 to 20 mined leaves common 
during June. 
Two adults and numerous parasites 
were reared from alfalfa leaves col¬ 
lected at Manhattan, Kans., by Mr. C. N. Ainslie in July, 1907. Mr. 
Ainslie also reared adults and parasites from infested leaves of alfalfa 
collected at Mesilla Park, N. Mex., May 21, 1909, and reported two or 
three mines in one leaflet not uncommon in the lower leaves of plants in 
a field of very young alfalfa. 
Specimens have been collected from altitudes varying from below sea 
level in southern California to 7,000 feet above sea level elsewhere. 
Fig. 4.—Alfalfa leaf with eggs of the serpentine 
leaf-miner in situ, somewhat enlarged, a, 
Bgg, greatly enlarged; b, same, in situ, with 
parenchyma of leaf partly dissected away, 
much enlarged. (Original.) 
