352 
as a variety of Phanerotoma tibialis Hald. The first named, which was 
described and figured from specimens reared from A. signatus (Insect 
Life, vol. v, p. 185) is an undoubted parasite of nigrinus, and the 
others are probably also parasites. A single specimen of each of the 
latter was reared with no other host present. It is rather noticeable 
that the parasites usually issued at the opposite end of the bud to that 
used as a place of exit by the host. 
AN ORTALID FLY INJURING GROWING CEREALS. 
(Chcetopsis a-nea Wied.) 
There is a rather common greenish-black fly, with black banded 
wings, as shown in the accompanying illustration, which ranges all 
the way from Canada on the north to the Gulf of Mexico on the south, 
occurring also in Cuba and the Bermudas, which belongs to the family 
Ortalidse, and is known as Chcetopsis cenea. The larva of this insect 
Fig. 34.— Chcetopsis cenea. a, larva, with spiracular opening, highly inagnitied, at left; b, puparium; 
c, adult, enlarged (original) . 
lives in a cavity which it forms within the stems of different cereal 
plants, including wheat, oats, corn, and sugar-cane. It works, as a 
general thing, near the base of the young growing plant, and either 
kills it outright or interferes with its growth to such an extent that it 
never perfectly matures. The eggs are laid in the leaf sheath, and the 
larva transforms to pupa in the same position. 
This insect was first brought to the attention of this office in July, 
1881, when larvae found in a piece of sugar-cane, which had been dam- 
aged by the sugar-cane beetle, Ligyrus rugiceps, were sent in by Mr. 
W. T. Holmes, of Cypremont, La. Later it was rather carefully studied 
in its relation to the oat crop by Mr. W. B. Alwood, in June, 1886. 
Mr. Alwood was then employed as an agent of the Division and was 
stationed at Columbus, Ohio. The larva? were found about the middle 
of June in an oat field, and had the effect of killing the blades at the 
