﻿THE WESTERN CORN ROOTWORM. 



1878, Prof. Riley 1 again received larva 1 , this time from Mr. G. Pauls, 

 of Eureka. Mo..- and from these he reared adult beetles on the 14th 

 of the following month. 



During the spring of 1874 the writer began to collect Coleoptera 

 in the vicinity of Waterman. Dekalb County. 111., but during this and 

 the following two years obtained only a single beetle of this species. 

 This single specimen, taken by the writer in the summer of 1874, was 

 captured in a field, of corn, and the failure to secure more individuals 

 during the next two years will indicate the rarity of the insect at that 

 time. Within seven or eight years, however, it had become so abun- 

 dant throughout the neighborhood, and indeed on the same farm, 

 then as now owned by the writer, as to render it impossible to secure 

 more than a single 

 full yield of corn 

 without changing for 

 a year to some other 

 c r o p. Up to that 

 time corn had gen- 

 erally been success- 

 fully grown on the 

 same ground for a 

 number of consecu- 

 tive years. The 

 writer's observations 

 in Dekalb County re- 

 flect with surprising 

 accuracy the condi- 

 tions that obtained 

 throughout the corn- 

 growing sections of 

 Illinois, as shown by 

 the information brought together by Dr. S. A. Forbes, then as now 

 State entomologist 3 of Illinois. May. 1884, the writer ceased to be 

 connected with Dr. Forbes's office and became associated with the 

 Division of Entomology of this department and was soon thereafter 

 transferred from Illinois to La Fayette, Ind. 



The principal damage, as previously indicated, is caused by the 

 larva?, and since 1882, in localities where no preventive measures 

 have been used, the damage to the corn crop has been very serious. 

 In 1885 Mr. Moses Fowler, of La Fayette, Ind., owner of an exten- 

 sive tract of land, estimated his loss during that season through the 

 ravages of the pest at $16,000, or about 15 per cent of the entire crop. 

 On the basis of this estimate the loss sustained in 24 of the corn- 



1 American Entomologist, vol. 3, p. 247, 1880. (Note. — See " Roots of corn injured by- 

 some unknown insect." American Entomologist, vol. 2, p. 275, 1870.1 

 • 2 Report of the Commissioner of Agriculture for 1878, p. 208, 1879. 

 3 14th Rept. State Ent. 111., pp. 10-31, 1883. 



Fig. 5. — Work of the western corn rootworm in roots of 

 corn; at right, rootworm in situ. (Original.) 



