TWO-WINGED INSECTS. I7I 



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 Flies, 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, — 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 as larvae, become 

 pupae in early summer, and in a few days assume the 

 winged state. 



Horseflies. 



These are generally large Flies, having a proboscis 

 inclosing very sharp lancets, with which they readily 

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

 their blood. They have very large eyes, occupying 

 nearly the whole head. There are several species, 

 and some of the largest are nearly an inch long. The 

 larvae live in the ground. Figure 287. 



