150 PROC. ENT. SOC. WASH., VOL. 20, NO. 7, OCT., 1918 



Rileya americana Girault. 



Rileya americana Girault, Can. Ent. XLVIII, 1916, p. 339. 



Female. Slightly larger than any of the other known North American 

 species and may be separated from any of the other species by the short 

 postocellar line. The malar space is more than twice as long as the width 

 of mandible; face below eyes coarsely striated, some of the striae extend- 

 ing upward* along the inner eye-margin far above the base of antennae; 

 carina separating cheeks from face strong and extending along the pos- 

 terior eye-margin to the top of eye; propodeum with a strong transverse 

 carina which is angulated at the middle, the area in front of this carina 

 and between the median line and spiracle with two carinae which converge 

 and meet at the anterior margin of propodeum ; area behind the transverse 

 carina coarsely striated; first tergite a little broader than long; second not 

 quite half as long as the first and about half as long as the third; fourth 

 longer than the first three combined; fifth, sixth, and seventh subequal 

 to each other and each about as long as the first; abdomen acuminate at 

 apex and considerably longer than the head and thorax; ovipositor ex- 

 posed at tip. 



Type and two paratype females in the U. S. N. M., Cat. No. 

 20323. The types of this species according to the Bureau of 

 Entomology records under No. 5140 were reared Sept. 7, 1891, 

 from a Cecidomyid gall on Helenium autumnale sent in by Mr. 

 H. G. Barlow from Cadet, Missouri. 



A NOTE ON THE ECONOMIC IMPORTANCE OF SAMIA CECROPIA 



(LEP.) 



BY C. N. AINSLIE. 



Very few of our working entomologists have escaped the 

 infliction of having brought to them from time to time, among 

 other rare things, finger worn specimens of Cecropia moths, 

 believed by the enraptured finder to be something entirely new 

 and valuable. Nearly all of our collectors are aware that this 

 huge moth is fairly common in most localities of the northern 

 states, and they also know that its habit of hiding among the 

 tree tops during the day is most effective in protecting it from 

 observation and capture. 



Insect Life, Vol. I, p. 155, records an instance of the appearance 

 of this species, Samia cecropia, in unusual and destructive num- 

 bers in Custer County, Nebraska, in 1888, but such cases seem to 

 be uncommon. In a heavily timbered locality the larvae of the 

 Cecropia may exist in large numbers and not be noticed unless 



