64 MASS. EXPERIMENT STATION BULLETIN 189. 



OTHER INSECTS FREQUENTLY MISTAKEN FOR THE 

 EUROPEAN CORN BORER. 



The Stalk Borer. 



The stalk borer Papaipema nitela Gn. is frequently mistaken for the 

 European corn borer. P. nitela attacks and tunnels in the stalks of a 

 great variety of plants, including corn, tomatoes, potatoes and many 

 other wild and cultivated plants. During the spring and early summer 

 the larva is quite commonly found in the same field and often in the same 

 plant with the European corn borer, but it may be distinguished from the 

 latter during its early stages by the presence of a wide transverse brown 

 band extending around the middle of the body. When nearly full grown 

 the P. nitela larva more closely resembles P. nuhilalis, but may be easily 

 distinguished from the latter at that time by the absence of the short 

 stout spines which arise from the light-colored abdominal areas of P. 

 nubilalis, and by the uniformly greater length and breadth of the P. 

 nitela larva. Another point of difference between the two species is that 

 P. nuhilalis pupates within its larval tunnels, while P. nitela leaves its 

 host, when full grown, and pupates in the soil. In corn the larval tunnels 

 of the two species are quite often similar, but the tunnels of P. nuhilalis 

 are generally packed with a light colored frass, and in some instances 

 contain the empty pupal skin, while the lai-val tunnels of P. nitela are 

 generally free from frass, or, if present, the frass is much darker and 

 composed of larger particles than that of P. nubilalis. 



Many reports of P. nubilalis injury have been found, upon investigation, 

 to have for their basis the injury caused by P. nitela. 



The Corn Ear Worm. 



Larvae of the corn ear worm Chloridea obsoleta Fab. are sometimes 

 mistaken for those of the European corn borer. The larvae of the first- 

 named species are frequently found feeding on the same ear of corn "with 

 larvae of P. nuhilalis, but may be easily distinguished from the latter by 

 the presence of varicolored stripes running lengthwise of the body, and 

 by theJact that larva? of the corn ear worm, as the name implies, confine 

 their operations, when feeding on corn, almost exclusively to the kernels 

 of the ear, and do not enter the cob or the stalk. They may generally 

 be found feeding on the surface of immature ears. 



Cutworms. 



Several species of cutworms are occasionally found feeding on the ears 

 of corn, but may be distinguished from larvae of the European corn borer 

 by the same characteristics as have been mentioned in the instance of 

 the corn ear worm. 



