INSECTS INJURIOUS TO GARDEN TRUCK 483 



they are less than one-fourth of an inch long. The flies lay 

 their eggs on the plant close to the surface of the ground, or 

 in the soil near the plant. The larvae soon mine into the 

 stalk or roots, where they feed for a few weeks, entering the 

 soil again to pupate. There may be two or three generations 

 during the summer. 



After the larvae have entered the plant but little can be done 

 to control them. Most of them can be killed by pouring a 

 teaspoonful of carbon bisulphide in a small hole four or five 

 inches from the plant, but this is hardly practicable on a large 

 scale. Control by cultural methods is more satisfactory. All 

 the old plants and roots should be destroyed early in the fall, 

 as many of the pupae pass the winter in or around these. Fall 

 plowing and crop rotation are to be recommended. Mustard 

 and other cruciferous wild plants should not be allowed in or 

 near the garden, as they also harbor this pest. If the cabbages 

 are not planted until most of the flies have laid their eggs on some 

 other plants they will escape serious injury. Seed beds should 

 be protected so the plants will not become infected before they 

 are transplanted. Some growers keep the fly from laying her 

 eggs on the plant by protecting it with a collar of tarred felt 

 paper which lies on the ground and surrounds the base of the 

 plant. Gas tar and other repellents have been used with more 

 or less success. Very early or very late radishes may escape 

 infestation. 



BEETS 



The Beet Leaf -hopper (Eutettix tenella). In some of the 

 western states where sugar beets are grown extensively a 

 condition known as beet curly-leaf, or blight, has caused con- 

 siderable loss, particularly in warm dry seasons. A few years 

 ago it was discovered that this condition was caused by a 

 very small whitish leaf-hopper that sucks the sap from the 

 leaves. When the plants are badly infested the beets become 

 stunted, or shrivel, and are of little or no value. 



So far no practicable means of control has been found, but 

 if the land is kept moist and other conditions made favorable 

 for the plants they will be better able to withstand the loss 



