WHEAT-SHEATH MINER 
By H. L. Seamans, 
Assistant in Entomology , Montana Agricultural Experiment Station 
INTRODUCTION 
In an investigation in 1915 of wheat plants ( Triticum spp.) supposed 
to be infested with Meromyza americana Fitch, two different forms of 
larvae were noticed, one a greenish larva, apparently that of M . americana , 
and the other a smaller, whitish one. Further examination showed the 
latter to be more plentiful and that the damage to wheat plants supposed 
to be caused by the M. americana was mainly due to the other species. 
A few plants were taken to the insectary at Bozeman, Mont., and the 
insects on coming to maturity were found to be mainly Cerodonta femoralis 
(Meigen), a species about which very little has previously been known. 
HISTORY OF THE SPECIES 
This insect was first described by Meigen in 1838 (2, p. 397) 1 as Agro- 
myza femoralis . At that time the genus Agromyza Fallen embraced a 
number of species now placed in genera since split off. In 1835, however, 
Macquart (1, p. 214) had used the name “Odontocera” to designate 
the genus which in 1861 Rondani (3, p. to) called “Cerodonta;” but, 
“Odontocera” being preoccupied, it can not be used here. In 1862 
Schiner (4 and 5) gave this genus the name “Ceratomyza,” and this is the 
name now used by some authors. Later writers on this group of flies, 
Melander (7) and Malloch (8, p. 331), have used Rondani’s “Cerodonta” 
for this genus, which has priority over “Ceratomyza”; therefore Meigen’s 
Agromyza femoralis then becomes Cerodonta femoralis. A search of the 
literature reveals practically nothing about the biology of this insect. 
Neither Aldrich nor Malloch discusses it, although Aldrich includes a 
note under the genus Ceratomyza, which reads: 
An undescribed Ceratomyza has been reared from young wheat plants at Pullman, 
Wash., by Prof. C. V. Piper; it causes considerable damage. 
According to recent information from Melander, who is now Ento¬ 
mologist at the Washington Agricultural Experiment Station, this fly 
was C. femoralis. Melander (8) mentions the species only in a key to 
the genus Cerodonta. 
DISTRIBUTION OF THE INSECT 
Melander (8) reports having specimens from Europe, Montana, Wyom¬ 
ing, Idaho, Washington, Oregon, California, and British Columbia. 
This would indicate that it is generally distributed in the Northwest. 
1 Reference is made by number to “Literature cited,” p. 24-25. 
(17) 
Journal of Agricultural Research, 
Washington, D. C. 
hm 
Vol. IX, No. 1 
Apr. 2, 1917 
Key No. Mont.—5 
