DIPTERS: FLIES. 157 



ceived its name from the belief that it was brought to 

 this country in straw by the Hessian troops under the 

 command of Sir William Howe. 



The American Wheat Fly is about one tenth of an 

 inch long, orange-colored, wings transparent, eyes black 

 and prominent ; antennae long and blackish, those of 

 the male being twice as long as the body, and con- 

 sisting of twenty-four joints, and those of the female 

 about as long as the body, and consisting of twelve 

 joints. The wheat insects, in their perfect form, ap- 

 pear between the first of June and the last of August. 

 They often move in immense swarms, taking wing in 

 the morning and evening, 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 maggots, which are found within the chaffy 

 scales of the grain. The eggs are laid at different 

 times, so that all do not come to maturity together; 

 but they appear to come to their growth in about four- 

 teen days. They prey upon wheat in blossom and in 

 the milk, and do not touch the kernel after it has be- 

 come hard. At length they cease eating, and soon after 

 shed their skins, after which they become active again, 

 and in* a few days descend to the ground. Here they 

 burrow, remain through the winter in the larva form, 

 pass into the pupa state in early summer, and in a few 

 days afterwards come forth in the winged state. 



HORSE-FLIES. 



These are generally large flies, having a proboscis 

 enclosing very sharp lancets, with which they readily 

 pierce the flesh of horses and cattle, in order to suck 



