270 



MISSOURI AGRICULTURAL REPORT. 



cell next to the plant is left open, so that the larva can go forth in search 

 of its food and return when necessary. Frequently during the daytime, 

 one searching for these insects will find pieces of grass leaves or even 



corn leaves with one end pulled into 

 the open end of these cases, and in- 

 side the larvae quietly feeding upon 

 it. 



When full grown these sod wcb- 

 worms are about one-half inch in 

 length and are of a red or reddish 

 Fig. 30. — The Striped Sod Web-Worm, brown color, with many dark, con- 



Crambus mutahilis. Adult Moth ; en- 

 larged about two diameters. spicuous, shiny spots Scattered over 



their bodies, each one bearing a rather stout hair. The work of these 

 insects in the corn plant is similar to what I have described for the 

 grass plant, except that where a corn field is very badly infested with the 

 insects, we frequently find several of these larvae eating each plant in 

 the badly infested areas. Occasionally they become so numerous in 

 the corn field as to practically devour the entire corn plant, but this is 



unusual. In the great bulk of cases the larvae 

 ■njore the plant and kill it by eating about the base 

 of the roots and cutting the roois in two, or more 

 frequently by eating off the young leaves and the 

 stem, or feeding on the stem below ground or 

 sometimes above it, as the case may be. In going 

 through the corn fields infested with these insects, 

 one will frequently find leaves or parts of leaves 

 cut off and some of which will be found protrud- 

 ing from the larvae cases above described. 



Of course, the work that these insects do in tlic 

 grass lands continues throughout the summer, 

 since we have some species with two broods, which 

 follow each other so closely that the work is practi- 

 cally continuous. In the corn field, however, the 

 damage that these insects do is confined entirely, 

 or nearly so at least, to the young corn plants. 

 When the larvae become full grown, they may 

 enter the cases in order to pupate, or they may 



Fig. .3 L— The striped Sod 



wcb-Worm, Crambus inu- icavc tlicm and enter the ground a short distance 



tdbilis, Larva; greatly 



^"•I'e-'d. and transform to pupae without the protection of 



the cases or cocoons. When the adults ai)pear they .soon lay their eggs 



for a second brood, provided the particular si>ecies has a second brood. 



