CORN INSECTS 



Corn seed beetles may again be a problem if germination is slow. This is when their attack 

 can reduce stands , sometimes seriously. Usually, but not always, this is more of a problem 

 with corn planted early. 



Soil applications of Dasanit, diazinon, Dyfonate, and phorate (Thimet) will control this 

 beetle. You can no longer depend on aldrin and heptachlor soil treatments to do the job. 

 Diazinon seed treatments alone will also control seed beetles. About 10 percent of the 

 people who used this method in 1969 complained about the effect on seeding rates. Adding 

 a dust to the seed may pose a reduced seeding-rate problem. To avoid this, when using 

 seed treatments : 



1. Treat seed in a separate container, so excess dust will not be in the planter box. 



2. Empty planter boxes frequently, to prevent powder from accumulating in the bottom. On 

 plateless planters, clean out the trap often. Clean up plastic plates and other plante 

 box mechanisms at the end of the day. 



5. Do not overdose. 



4. Check frequently for wear or chemical caking on the planter plates, particularly on 

 plastic plates. Some plastic plates also become "gummy" from chemical reaction. 



5. In some instances, using plates with a size-larger cell may be helpful. Adding some 

 extra graphite may also help maintain the seeding rate. 



When to use diazinon seed treater: 



1. Use it if you are using no soil insecticide at all, or when you are using aldrin, 

 heptachlor, or BUXten. Furadan may or may not control the beetles. 



2. You do not need diazinon seed treater if you are applying Dasanit, diazinon, Dyfonate, 

 or phorate (Thimet) as a soil insecticide . 



Soil Insecticides : Aldrin and heptachlor no longer satisfactorily controls the three corn 

 rootworms, seed beetles, seed maggots, or garden centipedes (symphylans) ; but do control 

 grape colaspis and wireworms with row or broadcast treatments . Aldrin and heptachlor also 

 control cutworms and white grubs, if broadcast and disk-in prior to planting. 



Dasanit, Dyfonate, and phorate (Thimet) control the rootworms, seed beetles, and seed mag- 

 gots, and provide some protection against garden centipedes. Diazinon will do the same, 

 except that it will not control the corn rootworms. Dyfonate will provide the best pro- 

 tection against garden centipedes. All four will give some protection against wireworms 

 and corn root aphids, very little control of cutworms, and no control of white grubs. 



Our Illinois recommendations are printed in Circular 899, Insect Control for Field Crops. 



Cautions : Do not apply the newer insecticides in the planter shoe next to the seed, as 

 you have done with aldrin or heptachlor. With some, the germination of the seed may be 

 affected. Apply them in a 7-inch band just ahead of the press wheel. 



