198 AGRICULTURE FOR COMMON SCHOOLS 



fastened under the weather-boarding of a house or any other 

 projecting ledge. 



10. Chinch-Bug. — This is one of the most destructive in- 

 sects that attacks farm crops. It is a true bug. All true hugs 

 have their mouth parts prolonged into a sharp beak with 

 which they puncture the skin or bark of the plant and suck 

 the juices instead of chewing the foliage or stem. The chinch- 

 bug hibernates over winter, hiding anywhere that it can find 

 protection in trash or stubble. Early in spring it lays its eggs 

 on the stems or roots of grass or wheat near the surface. By 

 the middle of summer the young are full grown. They then 

 begin to travel from one field to another. As soon as wheat is 

 ripe they go into the oats or corn. They are difficult to con- 

 trol. All trash should be cleaned up so they will not have 

 good places to hibernate. When they begin to travel a trench 

 made around the field into which they are moving and made 

 dusty by dragging a log in it will hinder them, as they cannot 

 climb up the dusty sides. Straw scattered in the trench and 

 burned will kill those thus trapped. 



11. Parasitic Insects. — By parasitic insects are meant 

 those insects which lay their eggs in the bodies of other insects. 

 When the eggs hatch the larvae live in the body of the attacked 

 insect and feed upon it. By the time the larvae are full grown 

 the insect is dead. In almost every case the parasitic insects 

 are beneficial. 



One of these parasitic insects attacks the tomato and to- 

 bacco-worm. When it is full grown it spins a small white 

 cocoon on the back of the worm. Every one has seen the 

 large tomato-worm with a dozen or more of these white co- 

 coons on its back. The Hessian fly is also attacked by an- 

 other small fly which destroys it. There are many kinds of 



