Animals of the Mississippi Bottoms near Quiney. 155 



An exhaustive treatment o£ the group in its relations to 

 fish culture would call for an account of every order of the 

 class; for while such orders as Hymenoptera and Lepidoptera 

 are very largely terrestrial, a glance at Prof. Forbes's most 

 recent paper on the food of fishes will show that even bees, 

 moths, and lepidopterous larva3 are devoured when chance 

 brings them within reach. Freshets surprise and carry into 

 the current of streams great numbers of terrestrial beetles 

 and bugs which live in the earth, under dead leaves and on 

 vegetation, and these furnish at such times no inconsiderable 

 part of the food of the smaller fishes. 



The common aquatic insects belong to the following 

 orders: Diptera, Coleoptera, Trichoptera, Neuroptera, Heraip- 

 tera (true bugs), Epheraeridge, Plecoptera, and Odonata. Some 

 of these live in the water throughout life; others in the larval 

 and pupal stages; still others in the larval and mature stages; 

 while a part are aquatic only in the larval condition. The food 

 varies greatly with the species and may vary with different 

 stages of the same insect. It consists of decaying organic mat- 

 ter, or of living plants or animals, while some forms constant- 

 ly take a mixed aliment. It is not possible therefore with our 

 present knowledge of the subject to calculate the effect of a 

 sudden removal of the whole group from its relations to the 

 other life of our waters; but considered only as fish food there 

 can be no doubt that the effect would be decidedly to the detri- 

 ment of fishes. Even those insects that prey upon the eggs 

 and young of fishes are themselves in turn devoured by the 

 adult fishes, and there seem to be very few indeed of the aquatic 

 insects that are not eaten by fishes in greater or smaller num- 

 bers. 



Order Diptera. ( Flies. ) 



Flies of at least nine families are aquatic in the larval 

 stage; but the majority of the individuals commonly collected 

 in our waters pertain to the families, Simulid«3, Culicida?, Chi- 

 ronomidas, and Tabanidse. To the first-named family belong 

 the notorious black fly and buffalo gnat. The larva of a very 

 similar species (perhaps the same as one or the other) is very 

 common in winter and early spring under rocks and wood in 



