THE DOBSON AND ITS FAMILY 



(Family Sialidce.) 



To this group belong the so-called alder flies, fish flies and 

 hellgrammites ; in fact, some of them have many popular names. 

 They have four broad wings, of which the hind ones are wide at 

 the base and capable of being folded behind. The wings have 

 numerous veins, both longitudinal and transverse, forming 

 irregular cells. There is a very complete metamorphosis, the 

 larva having strong-toothed jaws and the pupa being quiescent. 

 It is a small family, with only a few genera, but some of the 

 species are so striking in appearance, so interesting in habits, that 

 the group deserves really more extended mention than can be 

 given it here. All of the forms are aquatic or subaquatic in their 

 earlier stages. 



Of the typical genus Sialis we have only two species. They 

 comprise the smaller individuals of the family, and frequent 

 vegetation about the banks of streams. Very many eggs are laid 

 by a single female on the vegetation overhanging streams, from 

 two to three thousand being contained in a single egg mass. 



Most of our species belong to the genus Chauliodes, of which 

 the so-called comb-horned fish-fly ( Chauliodes pectinicornis L.) 

 is the commonest form throughout the United States east of the 

 Rocky Mountains. The eggs do not seem to be known, but the 

 .larvae are found in the water crawling along weeds and upon the 

 bottom. They are carnivorous, and feed upon other aquatic 

 insects, and when ready to transform to pupae crawl out upon 

 the bank, and are then found in cavities under stones or even 

 under the bark of trees. The adult insect has a wing spread of 

 three and one-half inches, and is a striking looking creature. 

 Chauliodes lunatus is a large and handsome species with brown 

 wings banded with white. The difference in size between its 

 males and females is very striking. 



Needham says that the larvae of Sialis infumata live in trashy 



