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CORN INSECTS 



Flea beetles will pounce on the corn as soon as it emerges, particularly in southern 

 Illinois. The relatively mild winter increased the chances of survival for this pest 

 These small, black beetles jump when disturbed. Although they are difficult to find 

 on the corn leaves, they can be observed best from a distance of a few feet, since 

 they leave the corn when you get near the plant. 



Flea beetles eat or strip the green from the plant leaf- -leaving tiny, white, elon- 

 gated scratch marks on the leaves. Damaged plants will generally turn silvery, then 

 brown. If enough plants are being killed to warrant the cost of insecticides, apply 

 3/4 of a pound of carbaryl (Sevin) or 1-1/2 pounds of toxaphene per acre as a band 

 spray over the row. The grassy areas in and around the field, such as waterways and 

 fence rows, should also be treated to prevent additional beetles from moving into the 

 field. Do not use carbaryl near bee hives or toxaphene near fish-bearing waters. 



Seed corn beetles may again be a problem if the seed germinates slowly. When this 

 happens , attacks by these beetles can reduce stands, sometimes seriously. Usually, 

 but not always, this is more of a problem with the corn that is planted early. 



The diazinon, planter-box seed treatments will control seed corn beetles. When these 

 treatments were first used, many farmers reported problems in maintaining even seed- 

 ing rates. However, new formulations have largely eliminated this difficulty. Here 

 are some guidelines for using planter-box seed treatments : 



1. Treat the seed in a separate container, so that excess dust will not replace the 

 seed in the planter box. 



2. Empty the 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 planter box mechanisms at the end of the day. 



3. 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," which is a 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 the diazinon seed treatment: 



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

 heptachlor, or chlordane. Furadan and BUX may or may not control the beetles. 



2. The diazinon treatment is not needed if you are applying Dasanit, diazinon, Dyfo- 

 nate, phorate (Thimet) , or prophos (Jolt., Mocap) as a soil insecticide. 



Our Illinois recommendations about soil insecticides are given in Circular 899, insect 

 Control for Field Crops. 



CAUTIONS 



Do not apply the insecticides BUX, Dasanit, diazinon, Dyfonate, carbofuran (Furadan), 

 phorate (Thimet), or prophos (Jolt, Mocap) in the planter shoe next to the seed, as 



