130 FARM FRIENDS AND FARM FOES 



2. If the pest is at work, gather some injured apples, and place in a 

 box with an inch or two of soil in the bottom. The larvae will probably 

 enter the soil, and you will be able to rear the flies. 



Root Maggots 



1 . What crops in your region are injured by root maggots ? 



2. Get some of the maggots from roots of radish, turnip, cabbage, or 

 onion. Keep in moist earth and see the change to ptiparia and later to 

 flies. 



3. Try to find eggs, larvae, and puparia about the roots of injured 

 plants. 



Leaf-mining Maggots 



1. Examine the leaves of beets, spinach, dock, and pigweed to find 

 discolored areas. If made by the leaf miners, the larvas may readily be 

 seen by holding the leaf up to the light or by opening the mine. 



2. Place some of the leaves that have larvae of good size in a bottle 

 of water. Set in a vivarium with earth in the bottom. The larvae will 

 probably pupate in the earth and later change to flies. 



The Story 



Tell or write the life story of one of these injurious flies that you know 

 most about. Illustrate by drawings on blackboard or paper. Perhaps 

 this outline will help you : — 



Size, color, and appearance of the fly. 



When and where the flies are found. 



When and where the eggs are laid. 



Size and color of the eggs. 



How soon the eggs hatch. 



What the larvae feed on. 



How long the larvae live. 



Where the larvae change to pupae. 



How long before the pupae change to flies. 



