necessary in Illinois at apply one of these insecticides to 3 or 4 million acres. 

 It will be cheaper to apply control measures when cutworms appear. 



When all treatments were compared with the untreated plots, the stands were so similar 

 that seed- attacking insects apparently were not present in damaging numbers. The ac- 

 tual insect counts support this. 



Corn Rootworms : Fields infested with corn rootworms were more common in 1970 than in 

 1969. Damage by rootworms would have been much more common if 2.7 million acres had 

 not been treated with rootworm insecticides. The returns for treatment in demonstra- 

 tion fields were about 10 bushels per acre. 



From our demonstration plots, we have drawn the following conclusions: 



1. If a very severe rootworm infestation is anticipated, one pound of carbofuran 

 (Furadan) per acre will provide the most -cons is tent results. This has been true 

 for three years . 



2. If light to moderately severe infestations are expected, any one of the following 

 insecticides will provide practical control: 



Rate, a ctual/A. i 





Planting ~ 

 Insecticide time Cultivation 



BUX 1 1 



carbofuran 3/4 



Dasanit 1 1 



Dyfonate 1 



phorate 1 1 



If insecticides are going to be used for cultivation- time treatments, use a seed treate 

 at planting time. 



Corn Seed Insects: We want to emphasize the importance of using seed treaters containij 

 diazinon to protect against attack by seed-corn beetles and seed-corn maggots. In many 

 fields with a long history of aldrin and/or heptachlor use, this may be sufficient- - 

 except for corn rootworm infestations. 



Fields Wh ere Roo tworms Are Not a Problem : For those who feel that the seed treatment 

 is not sufficient, we suggest instead planting- time treatments as a 7- inch band on the 

 soil surface: 



No. lb. actual 

 Chemical ingredient/A. 



diazinon 1.5 



Dasanit 1 



Dyfonate 1 



phorate 1 



