124 



Forty-first Report on the State Museum. 



^^^^ 



Entomological Society of Philadelphia, ii, 1863, p. 179, but its description 



is not yet published. The type specimens came from the upper 



Wisconsin river. 



Early Life of the Ephemera. 



Like the " dragon-flies " to which they are related, the ephemera 

 are aquatic in their early stages, swimming about quite actively in the 

 water, in pursuit of food. Some of the species, according to Westwood, 

 are of a more quiet nature, and live in burrows in the mud of the 

 banks, divided internally in two canals, each having a sej)arate open- 

 ing externally at the extremity, so that the insect can crawl in at one 

 hole and out of the other, without being obliged to make the awkward 

 turn it would have to do in a straight hole. 



Their aquatic life may be quite long, even extending to two or three 

 years, during which time, in one genus, they are said to undergo 

 as many as" twenty molts. 



The Short Life of the "Winged Insect. 

 Their winged life is not limited to a single day, as might be inferred 



from a popular name sometimes given them, 

 of "day-flies," yet it is much more brief than 

 that of most insects. It is believed that 

 some of the species do not live longer than a 

 day, while others have been kej)t alive for 

 weeks. Mr. B. D. Walsh has retained liv- 

 ing examples of Hexagenia bilineata (Say) in 

 his breeding cake for nearly a week* 

 (shown in Figure 50, from an example taken 

 by me in Schenectady, N. Y., in the month 

 Fig. 50.- Hexagenia bilineata of June.) De Geer has kept Ephemera ves- 

 (Say). pertina alive for eight days, and Stephens 



mentions having kept specimens of Cloeon dipterum alive for more 

 than three weeks ( Westioood's Introduction, ii, p. 27). 



Their Economic Value, Distribution, etc. 

 The Ephemerae have long been noted for furnishing excellent and 

 abundant food for fishes. Swallows and other birds also feed eagerly 

 upon them. They have a broad distribution over the world, from the 

 tropics up to high northern latitudes. Hundreds of species have been 

 described, while a very large number, from the difficulty attending 

 their study, are still awaiting description. Dr. Hagen's Synopsis of 

 North American Neu,rop)tera, published in 1861, contains forty-five North 

 American species. 



^jfp 



* PracticallEntomologist, ii, 1867, p, 95. 



