DIPTERA : TIPULARL^:. 415 



flies sometimes move in immense swarms in search of 

 fields of their favorite grain where they may lay their 

 eggs. The Hessian fly received its popular name from 

 the belief that it was brought to this country in straw 

 by the Hessian troops under the command of Sir Wil- 

 liam Howe. 



The American Wheat-Fly, C. tritici, Kirby, is one 

 tenth of an inch or less in length, orange-colored, the 

 legs long, slender, and pale yellow, wings transparent 

 and iridescent, eyes black and prominent, and antennas 

 long and blackish, those of the male being twice as long 

 as the body, and consisting of twenty-four joints, and 

 those of the female about as long as the body, and con- 

 sisting of twelve joints. The wheat insects, in their per- 

 fect form, appear some time between the first of June and 

 the last of August, according to locality or state of the 

 season. They often move in immense swarms, taking 

 wing in the morning and evening twilight, and in cloudy 

 weather, at which times they lay their eggs in the opening 

 flowers of the grain of barley, rye, and oats, as well as 

 wheat. The eggs hatch in about eight days, producing 

 little yellow larvae or maggots, which are found within 

 the chaffy scales of the grain. The eggs are laid, and 

 consequently hatched, at different times, so that all do 

 not come to maturity together ; but they appear to come 

 to their growth in about fourteen days. These insects 

 prey upon wheat in blossom and in the milk, and do not 

 touch the kernel after it has become hard. They pre- 

 vent the kernel from filling at all, which happens when 

 they attack the grain soon after the blossoming ; or they 

 cause the kernels to wither, which happens when they 

 attack it somewhat later. At length they cease eating, 

 become sluggish and torpid, and soon after moult their 

 skins, after which they become active again, and in a few 

 days descend to the ground of their own accord, or are 



