Oct. io, 1913 
Serpentine Leaf-Miner 
65 
On June 17, 1876, Dr. Riley noted that cabbage leaves in the vicinity 
of St. Louis, Mo., were infested by some leaf-mining larvae, and from 
these mines a single female fly was reared June 30, the larva pupating 
underground. Several years later, when apparently the same insect was 
found mining the leaves of cabbage, June 25, 1882, in Georgetown, D. C., 
by Mr. Theo. Pergande, interest in Dr. Riley's previous rearing from 
cabbage leaves in St. Louis, Mo., appears to have been revived. In 
1884 1 2 Dr. Riley described the species as Oscinis brassicae , evidently 
failing to recognize as identical his former rearing from mines in potato 
leaves, but calling attention to the similarity between his species and 
Oscinis trifolii Burgess, which had been described five years before. This 
same year (1884) the senior author found the same species in large num¬ 
bers attacking the leaves of white clover (Trifolium repens) at Oxford, Ind. 
Three years after its first discovery in Missouri by Dr. Riley and during 
June, 1879, the insect was observed to be very abundant about Washing¬ 
ton, D. C., attacking the leaves of white clover, and was carefully studied 
by Mr. Theo. Pergande. It must be borne in mind that at that time (1879) 
it was not positively known to attack clover or other plants elsewhere, 
and as a result of Mr. Pergande’s labors adult flies were secured which 
were afterwards described by Mr. Edward Burgess as Oscinis trifolii? 
In 1898 the late Mr. D. W. Coquillett, after examining the types of 
both Oscinis brassicae Riley and O. trifolii Burgess, decided that both 
were synonyms of Agromyza diminuta Walk. 3 Further results are shown 
by Mr. MalloclTs studies. 
Its wide distribution in the alfalfa-growing section west of the Rocky 
Mountains was especially noted by the junior author during the summers 
of 1911 and 1912, when, during the months of June, July, and August, the 
larvae were found mining in the leaves of alfalfa at almost every point 
visited in connection with the investigation of the alfalfa leaf-weevil 
(Phytonomus posticus Gyll.). The territory covered by these observa¬ 
tions comprises most of the alfalfa-growing section of Utah, southern and 
western Idaho, and southwestern Wyoming. In fact, the mines were 
present in limited numbers wherever alfalfa was found growing and in 
places widely separated by the uncultivated desert. This may be illus¬ 
trated by quoting from field notes made at Lucin, Utah, August 20, 1911: 
In a small field of alfalfa irrigated from a spring and in the midst of a desert west 
of Great Salt Lake these leaf-miners were of common occurrence. There is no alfalfa 
to the east for fully 90 miles and to the west for a distance of about 60 miles, this field 
being just 6 miles from the Utah-Nevada State line. Both larvae and pupae were 
observed. 
1 Riley, C. V. The cabbage Oscinis (Oscinis brassicce n. sp.). TJ. S- Comr, Agr. Rpt. 1884, p. 322, pi. 8, 
fig- 5. 
2 Riley, C. V. The clover Oscinis. (Oscinis trifolii Burgess [n. sp.]). U. S. Comr. Agr. Rpt. 1879, 
p. 200-201, 1880. 
3 Coquillett, D. W. On the habits of the Oscinidae and Agromyzidae, reared at the United States Depart¬ 
ment of Agriculture. U. S. Dept. Agr., Bur, Ent., Bui., n. s., no. 10, p. 78, 1898. 
