INSECTS INJURIOUS TO CORN 163 



grass. They are oval in form and of a yellowish color, each 

 being marked with regularly placed ridges. About two hundred 

 eggs are laid by each female. In from six to ten days the 

 eggs hatch. The young larvae soon form their loose silken webs 

 or tubes at or a little below the surface of the soil, burrowing 

 among the roots, and feeding upon the stalk and outer leaves, 

 or killing the plant by attacking the crown. The larvae vary 

 considerably in color, from a yellowish white, through pink, 

 to a reddish or brownish shade, and are studded with small 

 tubercles, each bearing a tuft of bristly hairs. The larvae become 

 full grown in from five to seven weeks and are then from one- 

 half to three-fourths of an inch long. During the latter part of 

 July they form cocoons, sometimes in the larval tubes, in which 

 they pass the pupal stage and from which the moths emerge 

 some twelve to fifteen days later. Eggs are laid for another 

 brood in grass lands during August and September, the larvae 

 hatching in September and October and becoming partly grown 

 before winter. They hibernate in their webs over winter, and as 

 soon as the grass commences its growth in the spring they are 

 to be found feeding upon it, becoming full grown early in May. 

 Preventive. As the natural food of these insects is grass, it 

 is not surprising that corn planted on sod land should be worst 

 injured; and though the injury done the grass may not have been 

 noticeable, when the available food is so greatly diminished by 

 substituting for grass the comparatively few hills of corn the 

 injury becomes much more serious and apparent. Though the 

 planting of corn on sod land is a most common practice, injury 

 by this and many other insect pests of corn most of whose 

 native food is grass might be avoided by planting any other 

 crop than a grain, such as potatoes. Otherwise plowing late in 

 the fall and harrowing so as to expose the larvae to the weather, 

 or plowing so deeply that they will be buried so that they cannot 

 regain the surface, will do much to prevent injury the next season. 

 Inasmuch as the moth will not lay her eggs upon plowed land, 

 if the land be plowed early she will be driven to other fields; 

 but the exact time of oviposition varies for different latitudes. 



