158 INSECT PESTS OF FARM, GARDEN AND ORCHARD 



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 146) are known as 

 11 bud worms." Later the 

 hollowing 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 infre- 

 quently results where the 

 pest is abundant. 



Life History. When the 

 caterpillars become full 

 grown in the fall they bur- 

 row down into the tap-root 

 and there pass the winter 



FIG. 133. Work of the larger corn stalk- in a small cavity at or near 

 borer: a, general appearance of stalk in- f u llr f flp p n f fi lp o-miinH 

 fested by the early generation of borers; l tne S round - 



6, same cut open to show pupa and larval About the time the land is 

 burrow. (After Howard, U. S. Dept. Agr.) bdng prepared for coril) 



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 moth is brownish-yellow in color with 



* Diatraea zeacolella Dyar. Family Crambidce. See Farmers' Bulletin" 

 1025, U. S. Dept. of Agr. 



