172 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



in midsummer, our earliest date (Illinois) being July 9, when 

 specimens were found on young leaves of corn. We have no 

 record whatever to show whence it comes or where it lives pre- 

 ceding this time. Having once commenced to breed on the food 

 plants mentioned, it continues there until freezing weather over- 

 takes it, when, with the death of its food plants, it gradually 

 disappears, leaving neither eggs nor hibernating adults on or 

 about these plants, and passing the winter we do not know how 

 or where." Its occurrence on barley in Texas in January may 

 throw some light upon its wintering habits in the South. " The 

 latest to develop in the field largely acquire wings, and as the sap 

 supply in the plant diminishes they fly away. Wingless females, 

 on the other hand, perish on the spot. Indications are thus 

 very strong that this is a migrating species whose second food 

 plant is thus far unknown." 



No experiments in the practical treatment of this pest seem 

 to have been recorded. 



The Larger Corn Stalk-borer * 



Throughout the South from Maryland to Louisiana and west- 

 ward to Kansas more or less serious injury is done by large white, 

 brown-spotted caterpillars which bore into the stalks. In spring 

 the young caterpillars bore into the heart of the young plant and 

 like other insects with similar habits (see page 161) are known as 

 " budworms." Later the holjowing out of the stalk so weakens 

 the plant that it is readily broken over by the wind. Consequently 

 a loss of from 25 to 50 per cent of the crop not infrequently results 

 where the pest is abundant. 



Life History. When the caterpillars become full grown in the 

 fall they burrow down into the tap-root and there pass the winter 

 in a small cavity at or near the surface of the ground. About the 

 time the land is being prepared for corn, from March 15 to April 30, 

 depending on the locality, the larva changes into a reddish-brown 

 pupa, from which the moth emerges in ten days or more. The 



* Diatraea zeacolella Dyar. Family Crambidce. See Circular 139, Bureau 

 of Entomology, U. S. Dept. of Agriculture. 



