Ii82 NEW TOEK STATE MUSEUM 



This beautiful crane fly [pl.8], which O'Sten Sacken attributes 

 to the Atlantic states and Quebec, I have been trying to rear f or- 

 several years at my home in Lake Forest; and I succeeded in the- 

 spring of 1901, and am now able to describe both larval and 

 pupal stages. 



The larvae bore in the dead and fallen stems of buttonbusb 

 and willow, where these lie on the mud at the borders of shal- 

 low ponds. I found them always in stems that were still par- 

 tially sound, tunneling beneath the bark or even into the deeper- 

 parts and into the sounder wood. These stems are frequently 

 submerged in spring and autumn, and even in summer, when the 

 pond has gone dry, they are always saturated with moisture. 

 The iirst two seasons that I tried to rear the larvae indoors I 

 failed, because I could not keep their surroundings at the 

 proper degree of moisture. In the spring of 1901 I placed the 

 stems or pieces of the stems containing Ihe larvae in the bot- 

 tom of a big glass jar, hung a large sponge saturated with 

 water in it, and laid on a loose cover, and with this apparatus 

 I reared them, every one. Larvae and pupae were collected 

 for rearing on May 18; images appeared on May 30. No imagos- 

 were seen at large, notwithstanding they were carefully looked 

 for several times after they began to appear in the breeding jar.. 



The most interesting thing about the larva, aside from its 

 wood-boring habits, is its singular adaptation to amphibian life. 

 It must needs live part of the time wholly submerged beneath 

 the waters of the pond, and part of the time out on land; it 

 has, therefore, both open spiracles and tracheal gills ; and, more- 

 over, its tracheal gills are so placed that they may be with- 

 drawn into the body in a dry time, where they escape the ilia 

 of too rapid evaporation. The spiracles are the two usual large 

 ones on the terminal respiratory disk, common to all tipulidae. 

 If a larva be taken from the stems and allowed to crawl on 

 the hand, these will be the only respiratory apparatus visible;, 

 no fleshy anal processes, such as are common in the family, will 

 be seen. The anal aperture will appear as a narrow longitudi- 

 nal slit between two opercular flaps. But, if the same larva be 



