INSECTS AFFECTING GRAINS, GRASSES, ETC. 105 



there hatch from these eggs some " very active, long-legged larvae, 

 with huge heads and strong jaws, which run about everywhere 

 seeking the eggs of locusts." Each of these larvae will consume 

 one of the masses or about thirty eggs. The subsequent life his- 

 tory of these insects is very complicated on account of their pecu- 

 liar habits, but the various stages are shown in Fig. 87. 



Control. As the eggs are usually laid in the ground in the 

 fall, deep plowing in late fall or early spring effectuallv buries 



jp IQ . g?. Various stages of a blister-beetle (Epicauta vittatd). (After Riley.) 



them too deep for the young nymphs to emerge. On alfalfa 

 land thorough disking is often used for the same purpose. 

 Thorough harrowing in the fall so as to pulverize the soil for 

 the depth of an inch will break up many of the egg masses, 

 though it is not as sure a control as plowing them under. 



When the young emerge, they may sometimes be destroyed 

 by burning over stubble, grass and rubbish where it is present 

 in sufficient quantities, or by augmenting it with straw, which 

 may be done to advantage on cold days when the nymphs are 

 congregated in such shelter. If the surface of the ground is 

 smooth and hard many may be killed by the use of a heavy 

 roller, particularly in the morning and evening, when they are 

 sluggish in their movements. Plowing a badly infested field 

 in a square, working toward the centre so as to drive the young 

 nymphs inward, will result in burying many of them in the furrows, 

 and the last may be burned or trapped in holes as described 

 below. Simple ditches 2 feet wide and 2 feet deep form 

 effectual barriers for the young hoppers. The sides next to the 

 crop to be protected should be kept finely pulverized by hauling 

 a log or a brush of dead branches through the ditch. The ditch 

 may be made as described for chinch-bugs and is handled in 

 the same manner, the little hoppers drifting to the bottom of 

 the ditch, where they are killed by the heat on a hot day or 



