June, 1914.] Lloyd: Lepidopterous Larv^ in Rapid Streams. 145 



LEPIDOPTEROUS LARV^ FROM RAPID STREAMS.^ 



By J. T. Lloyd, 

 Ithaca, N. Y. 



The aquatic lepidopterous larvae hitherto known are all inhabitants 

 of quiet waters, — lakes, ponds or pools. Herewith are described three 

 species of Elophila inhabiting swift waters, one species from N. Y. 

 state and two from Colombia, S. A. Li several ways they are unique. 

 They are found in very swift flowing water where one finds the 

 larvae of net-spinning caddis-flies and the nymphs of stone-flies and 

 may-flies. Here they live beneath sheets of silk spun over exposed 

 surfaces of current-swept rocks. In structure their unbranched, 

 filamentous gills, and expanded, fan-like setee of the labrum and 

 labial palpae will distinguish these larvae from any other described 

 species. Their pupae, unlike other lepidopterous pupae known to us, 

 are completely submerged. The life history and description of the 

 larvae and pupae are given more in detail on the following pages. 



Elophila fulicalis Clemens. 



Habitat. — During the summer of 191 1 larvae of this species were 

 found in Fall creek, about one mile east of the Cornell campus. At 

 the place where they occur most abundantly the creek is very swift, 

 flowing over a rough bottom of loose rocks. The depth at low water 

 varies from less than an inch to more than two feet. During the 

 spring freshets both depth and width are very greatly increased and 

 the stream becomes a roaring torrent. The larvae also occur, though 

 in less abundance, in the swift water on the flat rock floor a short 

 distance above and below the locality described. The bottom of the 

 creek is deeply coated with diatomaceous ooze intermixed with a 

 deposit of silt. This ooze is present on the upper and absent from 

 the under surfaces of the rocks. 



Cascadilla Creek, less than a mile distant from Fall Creek, is 

 slightly smaller especially during the dry season. In other respects 

 the two are very similar. In view of the fact that this larva inhabits 

 only a limited area in Fall Creek and is absent in similar localities in 



1 Contribution from the Limnological Laboratory of the Department of 

 Entomology in Cornell University. 



