202 Aquatic Organisms 



The groups of aquatic insects that are most com- 

 pletely given over to aquatic habits are the more 

 generalized orders that were long included in the single 

 Linnaean order Neuroptera (stoneflies, mayflies, dragon- 

 flies, caddis-flies, etc.)* Our knowledge of the immature 

 stages of aquatic insects was begun by the early micro- 

 scopists to whom reference has already been made in 

 these pages: Swammerdam, Roesel, Reaumur, and 

 their contemporaries.! They delighted to observe 

 and describe the developmental stages of aquatic 

 insects, and did so with rare fidelity. After the days 

 of these pioneers, for a long time little attention was 

 paid to the immature stages, and descriptions of these 

 and accounts of their habits are still widely scattered^ . 



It is during their immature stages that most insects, 

 both aquatic and terrestrial ones, are of economic im- 

 portance. It is then they mainly feed and grow. It 

 is then they are mainly fed upon. The adults of many 

 groups eat nothing at all: their chief concern is with 

 mating and egg-laying. Hence the study of the im- 

 mature stages is worthy of the increased attention 

 it is receiving in our own time. It will be a very long 

 time before the life histories and habits of all our 

 aquatic insects are made known, and there is abundant 

 opportunity for even the amateur and isolated student 

 of nature to make additions to our knowledge by work 

 in this field. 



*Under this name (we still call them Neuropteroids) the American forms 

 were first described and catalogued by Dr. H. A. Hagen in his classic ''Synopsis 

 of the Neuroptera of North America.'' (Washington, 1861). Bugs, beetles, 

 moths and flies have received corresponding treatment in systematic synopses 

 of their respective orders, only the adult forms being considered. 



fMuch of the best of the work of these pioneers has been gathered from 

 their ancient ponderous and rather inaccessible tomes, and translated by 

 Professor L. C. Miall, and reprinted in convenient form in his "Natural History 

 of Aquatic Insects" (London, 1895). 



J The completest available accounts of the life histories and habits of North 

 American aquatic insects have been published by the senior author and his 

 collaborators in the Bulletins 47, 68, 86 and 124 of the New York State Museum. 



