JOURNAL 



OF 



ECONOMIC ENTOMOLOGY 



OFFICIAL ORGAN AMERICAN ASSOCIATION OF ECONOMIC ENTOMOLOGIST 



Vol. 12 JUNE, 1919 No. 3 



EAR WORM INJURIES TO CORN AND RESULTING 



LOSSES 



By Roger C. Smith, Scientific Assistant, Bureau of Entomology, Charlottesville, Va. 



After reading practically all of five hundred and twenty-five references 

 to the corn ear worm {Chloridea obsoleta Fab.) in literature, it has been 

 observed that two serious sources of loss due to the activities of this 

 well known pest have been overlooked. A brief discussion, therefore, 

 of the various types of injury to corn caused by this insect, with obser- 

 vations from last year's study may prove of some practical value. ^ 



It is well known that in most of the ear worm territory, the first 

 generation of moths frequently oviposit on the unfolding leaves in the 

 heart of the young corn plant. The larvae upon hatching attack the 

 tender leaves (PI. 1 1 , fig. 1 ) eating large and irregular holes in them. This 

 injury has been variously designated in different localities as "rag worm" 

 injury (Virginia), "shatter worm" (North Carohna), "heart worm" 

 and "bud worm" injury (general). It would appear that there must 

 be some injury to the vitality of the young corn plant though a few 

 injured stalks under observation at this laboratory apparently over- 

 came this injury and produced ears entirely comparable to stalks not 

 thus injured and under the same growing conditions. Ear worm larvjB 

 have several times been reported as boring into the stalk (Caudell, 

 1902) ,2 but this habit is apparently unusual according to our 

 observations. 



The developing tassels are next attacked by the larvae (PI. 11, fig. 2). 

 In this locality nearly grown larvip are usually found doing Ihis injury 

 and in the few days' eating do considerable damage to the dovoloping 



1 Acknowledgment is made to Mr. \V. J. Phillips in charKC of this lalwratory for 

 suRKCstions and criticism of this pa{)er. 



« Caudell, A. X. Notes on Colorado Insects. Bui. .38. X. .'^. Div. of Ent.. U. S. 

 Dept. of Ag., November 1902, p. 38. 



