704 CHARLES PAUL ALEXANDER 



GENERAL CONSIDERATIONS 

 REPRESENTATIVE CRANE-FLY LIFE HISTORIES 



The life histories of but few species of crane-flies have been studied 

 in detail. The very nature of the habitat (mud or earth) required by 

 most species of the family renders it a most difficult operation to rear 

 the species from the egg to the adult and note the various stages, their 

 molts, their habits, and other features. The subfamily Cylindrotominae, 

 the immature stages of which live on the leaves of various higher plants 

 and curiously resemble the caterpillars of certain Lepidoptera, furnishes 

 species whose habits are more readily studied than most others, and as 

 a result the immature stages of this group are better known, perhaps, 

 than those of any other section of the family. Two widely different 

 species have been chosen, and their life histories as they are known at 

 present are here outlined. The first is a species of Eriocera, a powerful, 

 semi-aquatic carnivore; the second is a species of Cylindrotoma, a ter- 

 restrial herbivore. In the text which follows, notes on the life activities 

 of various other species are given, but the gaps in the knowledge of this 

 phase of the subject are very considerable and there still remain innumer- 

 able interesting facts to be ascertained. 



Eriocera longicornis (Walk.) 



The common crane-fly Eriocera longicornis is widely distributed over 

 the northeastern United States and Canada. Altho the species is local 

 in its distribution, the flies may be found in abundance wherever it does 

 occur. The situations that favor the presence of these flies are large 

 streams or rivers with sand or gravel bottoms and banks. The following 

 notes were taken, partly in Fulton County, New York, along the Sacan- 

 daga River, and partly in Tompkins County, along Fall and Cascadilla 

 Creeks. Some of these data have already been published by Alexander 

 and Lloyd (1914:12-18) and by the writer (Alexander, 1915 c: 149-152). 



On May 27, 1914, the adult flies were exceedingly numerous near the 

 village of Northampton, Fulton County. They were present in untold 

 myriads, and at every step they arose in clouds from under foot or from 

 the leaves of chokecherry on which they rested. They sat on the leaves 

 with the head directed away from the observer, ready to take instant 

 flight, and at the first approach of a possible enemy they darted up into 



