DIRECTIONS FOR COLLECTING AND REARING DRAGON FLIES, 

 STONE FLIES, AND MAY FLIES. 



By James G. Needham, Ph. D., 



Lake Forest College, Lake Forest, Illinois. 



It is the purpose of this paper to outline briefly some simple and 

 reliable methods of obtaining material illustrating the life histories of 

 some of the commoner aquatic insects. Some knowledge of insects in 

 general and of the apparatus universally employed by entomologists — 

 nets, cyanide bottles, pins, papers, etc. — is assumed. It is proposed 

 merely to supplement the accounts given in the general text-books 

 and in Dr. Eiley's excellent paper, Directions for Collecting and Pre- 

 serving Insects,^ with some new and more detailed methods of dealing 

 with aquatic insects. While the simple apparatus here described has 

 been devised or adapted for the purpose of studying insects of the 

 orders named in the title, it will be found to work well for aquatic 

 insects in general. 



COLLECTING AQUATIC NYMPHS. 



For collecting purposes the insect life of the water may be divided 

 according to habitat into three groups, each requiring methods adajjted 

 to its situation. 



1. Forms living on the 'bottom. — Here belong representatives of every 

 order having aquatic species. The organic material which is continu- 

 ally falling upon the bottom of ponds and streams supports a teeming 

 population and forms a stratum of great biologic richness. Fqw stone 

 flies are found on the bottom in still water, but dragon flies and may 

 flies are there abundant. 



Where there is much loose material on the bottom, there is no better 

 collecting instrument than a common garden rake. With it the debris 

 may be drawn ashore and the insects picked by hand. Withdrawn 

 from the water, they generally make themselves evident by their active 

 efforts to get back. The rake is especially useful in the spring, while 

 there is as yet no new growth of well-rooted waterweeds to interfere 

 with hauling it. Its use is to be commended, because the places best 

 adapted to it, such as small bays in the edges of ponds where aquatics 

 grow abundantly, and eddies in streams, harbor also an abundant 

 insect fauna. 



1 Bulletin No. 39, U, S. National Museum, Part F, 1892. 

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