﻿BULLETIN 



u 



OF THE 



No. 



Contribution from the Bureau of Entomology, L. 0. Howard, Chief 

 September 27, 1913. 



THE SOUTHERN CORN ROOTWORM, OR 

 BUDWORM. 



By F. M. Webster, 

 In Charge of Cereal and Forage Insect Investigations. 



DISTRIBUTION. 



The parent of the southern corn rootworm (Diabrotica duodecim- 

 piinctata Oliv.), or, as it is often termed, the budworm, is a yellow 

 or greenish-yellow beetle having 12 black spots on the back, as shown 

 in figure 1, • a, from 

 which its specific name, 

 meaning " 12-spotted," 

 is derived. It is closely 

 allied to the almost 

 equally common striped 

 cucumber beetle {Dia- 

 brotica vittata Fab.), 

 and also to the parent 

 of the even more de- 

 structive western corn 

 rootworm (Diabrotica 

 lonc/icornis Say). 

 Throughout the coun- 

 try east of the Rocky 

 Mountains, extending 

 from southern Canada 

 southward to North 

 Carolina, Tennessee, 

 Arkansas, and Oklahoma, these 12-spotted and striped beetles to- 

 gether frequent squashes and pumpkins, often collecting in num- 

 bers in the blossoms. The 12-spotted species during late summer and 

 fall also frequents, often in conspicuous numbers, the flowers of the 

 various species of goldenrod (Solidago). 



The larvae (fig. 1, c) do not generally attack growing corn in suf- 

 ficient numbers to cause any considerable injury, except perhaps 



Fig. 1. — The southern corn rootworm (Diabrotica cluo- 

 decimpunctata) : a. Beetle; b, egg; c, larva; d, anal 

 segment of larva ; e, work of larva at base of corn- 

 stalk ; /, pupa. All much enlarged, except e, reduced. 

 (Reengraved after Riley, except f, after Chittenden.) 



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