AQUATIC INSECTS OF FRESHWATER 



Sericostoma americana, Rhyacophila torva, Leptocerus transversus and Mac- 

 ronema zebratus, each also representative of a distinct genus of the order 

 Trichoptera. 



Order Thysanura. This order includes the so-called Bristle-tails, 

 Spring-tails, Fish-moths and others; wingless insects which undergo no 

 metamorphoses and retain the larval form in the adult. The mouth parts 

 are developed for biting and chewing soft substances and they are some- 

 times provided with rudimentary legs only. The sub-orders comprise the 

 Bristle-tails or Cinura; the Spring-tails or Collembola, and the Water 

 Spring-tails or Poduridse, with only the last of which we are concerned. 



Water Spring-Tails belong to the family of Poduridae, of which 

 P. aquatica. Fig. 217, is often found on the surface of quiet ponds and 

 still water. It is a black insect with six legs, dis- 

 tinctly segmental abdomen without a constriction to 

 divide it and the thorax, plumed antennas, reddish 

 legs provided with hairs and sharp claws, devoid 

 of wings, and of which the larvae may be distin- 

 guished from the adult only by their still smaller 

 size. Achorutes nivicola is another species some- 

 times found under the surface of the water, and 

 Lepidocyrtus americanus'vcv greenhouses, under logs fig. 117. Water-sprfngtaii, 

 and in similar situations. They are small entirely ^odum. a,iuauca. Enlarged. 

 harmless insects, mentioned only because they often attract the attention 

 of the fish culturist and Natural History collector. 



Order Diptera. This order includes insects which may be properly 

 called Flies; those having but two wings borne by the mesothorax and 

 include the Mosquitoes, Midges and Gnats. The wings are thin and 

 membranous, the mouth parts formed for sucking, the thorax and abdomen 

 slender, and the eyes distinct and placed at the sides of the head. The 

 order includes the Mosquitoes or Culicidse; Net-winged Midges or 

 Blepharoceridse and Chironomidffi; Moth-like Flies or Psychodidse, Crane- 

 flies and False Crane-flies, Black and Bufi^alo-flies, Horse-flies, Soldier-flies, 

 the Long-legged flies. Snipe-flies and many others. 



Mosquitoes belong to the family of Culicidse, small flies with narrow 

 wings and long and slender abdomen, of which the males have plumelike 

 antennae. They frequent moist localities and pass all the stages of develop- 

 ment to the perfect insect in the water, a new brood appearing every 

 three or four weeks. In depositing the eggs the female rests upon some 

 floating object with the anterior legs, the middle legs rest on the water and 

 the posterior legs are crossed to hold the eggs as they are laid, with their 

 longer diameter vertical, and glued together to form a raft of often 200 



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