112 



PESTS OF GARDEN AND FIELD CROPS 



Fig. 74. — The Western Corn Root 

 worm. Adult. Enlarged and natu 

 ral size. Original. 



two fifths of an inch long, slender, whitish or yellowish, and has a 



black or brown head. 



The adult is a small beetle, greenish in color, one fourth of an inch in 



length. It is 

 found occasion- 

 ally on melons 

 or squashes, along 

 with its relative, 

 the striped cu- 

 cumber beetle, 

 but is more apt 

 to be seen on sun- 

 flowers, golden 

 rod, or thistle 

 blossoms. 

 There is one generation each year. The winter 



is passed as eggs beneath the surface of the ground. 

 The simplest means of control is crop rotation. 



The eggs are laid only in cornfields in late summer, 



and the larvae are injurious only to corn. If corn 



is planted in fields that have been in other crops, it 



will not be injured. In practice it is usually safe 



to run corn two years in succession, changing to another crop the 



third year. 



Corn-root Webworms (Crambus spp.) 



Young corn plants are seriously injured or killed by several species 

 of webworms feeding on the roots, or on the stalk close to the surface of 

 the ground. The outward evidence of attack is the stunted growth of 

 the corn or the death of young plants. Injury is always worse in ground 

 just broken up from sod. 



The same insects attack in similar fashion young tobacco plants in 

 certain eastern sections. 



Several species are recorded, all in the genus Crambus, and including 

 C. vulvivagellus Clem., C. luteolellus Clem., C. trisectus Walk., and C. 

 mutabilis Clem. 



Fig. 75. — Work 

 of the West- 

 ern Corn Root- 

 worm. Origi- 

 nal. 



