INSECTS IXJURIOrS TO THE SUGAR-BEET. 201 



of iin incli, quite variable in color, but generally an orange 

 or reddish yellow, inclining to a shade of gray. Their 

 characteristic dark and light markings are well shown in 

 the figure. The eggs of the latter worm are a pale yellow, 

 circular, somewhat flattened, and laid either singly or in 

 rows of four or five. The yonng worms hatch in a few 

 days, and often do serious injury by feeding upon the 

 foliage of the plant, always spinning a light, silken web 

 over them. Most of the feeding is done at night, but 

 during the last stage they may be found during the day. 

 This brood matures in about ten days after hatching, 

 pupates, and the moths emerge early in July, giving rise 

 to the destructive July brood of worms. The larv^, or 

 '* web-worms, ^^ are about five-eighths of an inch long when 

 full-grown, and, like the moth, are variable in color, being 

 either a pale, dark, or even greenish yellow. They are 

 distinctly marked by several rows of black spots, which are 

 surrounded by a plain border, as in Fig. 149. 



Jiemedies. — Deep plowing or thorough harrowing in the 

 fall after the larvae have entered the cocoons in the earth 

 will destroy large numbers of them. When the worms 

 appear in destructive numbers upon the foliage they may 

 be controlled by a spray of Paris green or other arsenite, 

 using one pound to 125 gallons of water, providing, of 

 course, that the tops are not to be fed to stock. An 

 under- spray nozzle should be used, so as to reach all parts 

 of the plant in an effective manner. When present in 

 large numbers and doing serious injury the worms can be 

 more quickly killed by spraying with strong kerosene 

 emulsion, but this will only kill those hit, and an ar- 

 senite should also be applied without delay. 



