226 



ELEMENTARY ENTOMOLOGY 



They are grayish-black, not over one twenty-fifth of an inch long, 



and the larvae develop in the water in stumps and logs and under 



damp, dead bark. 



The net-winged midges (Blepharoceridae) are so called on account 



of the peculiar network of small veins crossing the main wing- 



veins around the irfargin of 

 the wing, which are peculiar to 

 this family. The small, black 

 larvae live in masses on the 

 rocks in swift-running moun- 

 tain streams, and seem to have 

 but seven segments strongly 

 constricted at each joint. 



The Dixa-midges (Dixidae) 

 include but a single genus, 

 whose larvae are also aquatic. 

 Both of the last families com- 



, larva ; , pupa ; ,, aduU. (After Weed, 



species, and lack the whorls 

 of hairs of the male antennae. 

 The black-flies (Simuliidae). Another pest of mountain lovers is 

 the black fly, the females of which are most bloodthirsty and often 



FIG. 357- The fickle midge (Sciara inconstant), a fungus-gnat sometimes trouble- 

 some in greenhouses. (Much enlarged) 



a, male ; Z>, genital organs of same ; c, female ; d, enlarged antennal segments of same ; 



^, maxillary palpus of same ; /, tip of abdomen of same from side ; g, pupa ; ^, larva. (After 



Chittenden, United States Department of Agriculture) 



