55 



meters (from one twenty-fifth to nearly one-twelfth of an inch). The last joint 

 of the antennte is nearly circular in outline, and on the upper edge is a nearly bare 

 bristle or arista; on the upper part of the otherwise opaque head is a polished, 

 nearly triangular spot that extends from tlie]^extreme vertex almost to the antennae. 

 The wings are nearly transparent and are without an auxiliary vein — that is, there 

 are only three (instead of four) veins that terminate in the front edge of the wing 

 before its apex; the vein bordering the front edge of the wing extends beyond the 

 extreme apex of the wing; the usual two small cells near the base of the wing are 

 wanting, the anterior one being confluent with the discal or central cell, while the 

 posterior one is wanting, there being only one cell (the axillary) behind the fifth 

 vein. The legs are devoid of bristles and of stout, apical spurs, and are rather short 

 and robust; the first j(jint of the feet is rather slender and longer than any of the 

 other joints. The thorax is also without bristles, except along the sides and across 

 the posterior end; it is somewhat polished and is devoid of gray dust. The face 

 does not project strongly forward on its lower part; the proboscis is short, robust, 

 and terminates in the fleshy lips. 



CLOSE RESEMBLANCE TO OSCINIS SOROR MACQ. 



Oscinis soror Macq. is very closely related, but may be distinguished 

 by the fact that the polished spot on the upper part of the head 

 extends only about halfway from the vertex to the antenna, instead 

 of almost reaching the antenna?, as in the preceding species. (D. W. 

 Coquillett.) 



At present, owing to the confusion of this species with soror^ an 

 account of which will follow, it seems impossible to give desirable 

 descriptions of the preparatory stages of this insect. I have followed 

 those of Professor Garman, not knowing whether he was dealing with 

 this species 6r not, but because his descriptions seem to me to apply 

 as well to this as any that 1 could suppl3^ It must be kept in mind, 

 however, that this is only a temporary makeshift to give some kind of 

 an idea of what these look like, and thus enable the farmer to reduce 

 the uncertainty as to the identical species that is injuring his crop, 

 and that later and more careful investigations will probably show that 

 this and several other species, but with habits that are practically the 

 same, have been confused, and thus the present arrangement serve a 

 practical if not a scientific purpose. 



Egg. — The egg of what is supposed to be this species was described by Mr. Per- 

 gande in the Department notes as follows: Colorless, polished, and longitudinally 

 ribbed with numerous extremely fine transverse striae. 



Larva. — Cylindrical, white, with faint yellow cast. Body composed of thirteen 

 segments. No head and no legs. Mouth with two strong black hooks. Posterior 

 segment of body with a pair of knob-like prominences. Length of alcoholic speci- 

 mens, 0.14 inch. 



Pupa. — In this stage the insect is inclosed in the hardened and brown skin of the 

 larva and this is called the puparium. This last is bright yellowish-brown, with 

 distinct and very finely wrinkled divisions. The two knob-like prominences in the 

 larva are retained and are conspicuous at one extremity. The black hooks of the 

 larva are molted with the skin and can be seen through the puparium. The obso- 

 lete mouth of the larva is withdrawn, blackened, and wrinkled. Length from 0.10 

 to 0.14 inch. 



