192 AGRICULTURE FOR COMMON SCHOOLS 



all winter and in spring begin to eat everything within reach. 

 In orchards some kinds of cutworms crawl up the trunks of 

 trees and cut off the young shoots. The cutworm cuts off the 

 corn or garden plants just above the surface of the ground. 

 If sod is plowed early in the fall the moths have to find other 

 places to lay their eggs, so that not many will be found in the 

 field next spring. Late plowing disturbs the winter bed of 

 the larvae and causes many to be killed by the cold. 



4. Hessian Fly. — This is a very small fly, like what is 

 usually called a gnat. The eggs are laid on the upper surfaces 

 of the lower leaves of wheat or other grass-like plants. As 

 soon as hatched the larva slips down inside of the sheath and 

 begins to absorb the juice of the plant. The larva is a maggot 

 and cannot chew the plant but absorbs its juices. At first it 

 is white but when it is full grown it is brown. Eggs are laid 

 in the fall and in the spring, so that there are two broods 

 each year. Adult flies come from the larvae in the spring. 

 These at once lay eggs for the summer brood which comes 

 forth late in the summer, ready to lay eggs on the fall-sown 

 wheat. 



5. Codling-Moth. — Thijs moth lays the egg that makes the 

 worm which we find in apples in the summer-time. The egg 

 is laid at the blossom end of the apple just as the blossoms drop 

 off in spring. The egg soon hatches, the worm eats outside 

 a couple of days, then works into the apple and eats around 

 the core until it is full grown. It then comes out and finds 

 a hiding-place under the bark, spins a cocoon, and rests until 

 next spring when it hatches out as a moth again. In most 

 places there are two broods. The first larvae change to moths 

 early in summer, and these moths lay eggs on the green apples, 

 generally where two apples touch each other. 



