310 THE ESSENTIALS OF AGRICULTURE 



400. Fall plowing and disking. Many injurious insects, such 

 as cutworms, corn-ear worms, wireworms, and white grubs, pass 

 the winter as larvae and pupae in the soil, or hibernate about 

 the roots of weeds and grasses. Breaking up the soil in the 

 late fall and exposing these wintering forms to their natural 

 enemies and to unfavorable weather will greatly reduce their 

 number. Disking alfalfa is an effective method of destroying 

 grasshoppers, army worms, and cutworms. 



401. Place and time of planting. Too frequently corn and 

 other cereals are planted in places where they will be subjected 

 to the attack of insects that are already present. Corn following 

 grass or clover sod is likely to be attacked by cutworms and 

 white grubs, and if planted in marshy tracts, is in danger from 

 wireworms and billbugs. Planting at the proper time is a protec- 

 tion to many crops ; for example, wheat sown after the first week 

 in October is usually free from the attack of the Hessian fly. 



402. Crop rotation. By a thorough system of crop rotation 

 the increase of many insect pests may be checked or prevented. 

 This will starve out such an insect as the Western corn-root 

 worm, which is never injurious to the corn after the land has 

 been in small grain. White grubs, cutworms, wireworms, plant 

 lice, and the Hessian fly may be controlled in this manner. 



403. Good soil, clean seed, and thrifty plants. Thorough 

 preparation of the soil induces rapid growth and thrifty, vigorous 

 plants. It also disturbs and exposes the insects that are in the 

 ground. Plants which are in good, thrifty condition are better 

 able to resist the attack of insects. Plants in a weak condition, 

 or with no vitality, soon succumb to the attack of an insect 

 enemy. A good stand lessens the danger from injurious insects. 

 The field partly grown up with foreign weeds and grasses will 

 encourage pests, hence the importance of weed-free seed. 



404. Barnyard fowls and native birds. Chickens, guineas, 

 ducks, turkeys, and geese are continually in search of those 

 insects that may be found upon low plants and in grasses and 

 weeds, and under rubbish and fallen leaves. Grasshoppers have 

 often been controlled by these fowls. 



