336 HOUSEHOLD INSECTS 



ture the flesh of man and beast whenever opportunity is 

 offered. The males, as indicated by the structure of 

 their mouth parts, are harmless. In general, black-flies 

 are more annoying to man than strictly injurious, although 

 several cases of reputed deaths due to the bites of these 

 flies are on record. Some people certainly suffer much 

 torture from the attacks of black-flies in northern latitudes. 

 They are active during the day only and seem to prefer 

 bright sunshiny weather. It is said that the flies will oc- 

 casionally bite on moonlight nights. 



The young, or larvae, of black-flies live in swiftly flowing 

 water. The eggs are laid in patches beneath the water 

 and attached to stones or other objects. Here they hatch 

 and the larvae finally transform to pupae. The adults 

 escape from the pupal skins and rise to the surface each 

 in a bubble of air. In some instances so many of the 

 adults emerge at the same time that the water is said to 

 fairly boil as each one arises in its air bubble. 



There are two species that occur, at times in vast swarms, 

 in the Mississippi Valley from Illinois southward, namely, 

 the turkey-gnat (S. meridionale) and the buffalo-gnat 

 (S. pecuarum). These are essentially southern forms, 

 although they occur from New Hampshire to Texas. 

 They are a most serious pest to stock in the South and often 

 cause a tremendous loss of life among mules, cattle, sheep, 

 hogs, and fowls along the regions bordering the lower 

 Mississippi. The animal attacked becomes frantic and 

 runs wild at first, but finally grows quiet, lies down, and 

 dies, perhaps all within the space of three or four hours. 

 Even deer come to the smudges built by the planters and 

 occasionally allow people to rub the gnats from their 

 bodies. 



