212 INSECTS AFFECTING FIELD CROPS 



Crop rotation is, of course, advisable, as is also pasturing with 

 hogs. Figure 225 illustrates the different stages; and two eggs, 

 much enlarged, are shown in Figure 226. These eggs are laid in sod. 

 The Stalk-borer (Papaipema nitela Gn.). This moth lays 

 its eggs in the autumn upon ragweed, dock, and other plants which 

 are normally the food of its larvae. The young larvae climb to the 

 leaves and first mine small galleries in the leaves. When the leaves 

 are riddled, they work down the bases and 

 enter the stalks. After one plant is de- 

 stroyed, the worm may migrate some dis- 

 tance and attack another. Infested plants 

 wilt above the point of injury. This pest 

 is sometimes noticed in corn and is entered 

 as a corn pest. 



FIG. 226. Eggs of May Control. Clean farming is the best 

 method of control. Weeds in the vicinity 



of the garden should be destroyed by removal and burning in 

 early spring. The insect has many parasitical enemies, and the 

 injury is largely local in nature. Infested plants should be 

 promptly destroyed where practicable, to prevent the migration 

 of the worm to another plant and thereby increase the damage. 

 Little trouble will be experienced in fields that are clean. 



TURNIP INSECTS 



Field and garden turnips are frequently infested with plant 

 lice. No practical remedy is available, as kerosene emulsion can- 

 not easily be sprayed on the under side of the leaves. Parasites 

 help to keep them in check. The cabbage maggot is also a 

 turnip pest. 



BARLEY, TIMOTHY, RYE, AND GRASSES 



These crops are all injured to a greater or less extent by in- 

 sects described under other heads and in all cases the treatment 

 is practically the same as that already given. See corn and small 

 grains. 



On timothy one frequently finds the false chinch bug (Trapc- 

 zonotus nebulosus Fab.), often mistaken for the true chinch bug, 

 since it has the same bedbuggy odor. It also resembles it some- 

 what in coloration and belongs to the same family. Timothy is 

 rather seriously injured by this bug, which is, generally speaking, 

 a feeder upon weeds. 



