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COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT, WEED & PLANT DISEASE .SURVEY BULLETIN 



TATE/COUNTY/LOCAL GROUPS/US DEPARTMEMT OF AGRICULTURE COOPERATING 





FOR IMMEDIATE RELEASE 



USRARY 



No. 11, June 6, 1969 



This series of weekly bulletins provides a general look at the insect, weed, and plant 

 disease situation (fruit and commercial vegetables excepted) , along with suggested, 

 abbreviated control measures. Each individual should check his own fields to deter- 

 mine local conditions. 



INSECTS 



CORN INSECTS 



Seed-corn beetles are still present in many cornfields throughout the state. Where a 

 diazinon seed treatment was not used, damage may yet occur to newly emerging corn 

 plants. If replanting is necessary or if the corn is just now going in, be sure to 

 treat with diazinon. Corn now 6 inches high or taller will probably escape further 

 damage by the beetle. 



The slender seed-corn beetle is migrating now and was picked up in light traps by the 

 thousands this past week. Damage caused by the seed beetle may appear in fields, but 

 the beetle could be gone. 



True armyworms have been reported doing damage to corn following rye where a no-tillage 

 system of planting was used. The armyworm moths laid eggs in the rye, and the newly 

 hatched worms are feeding on the corn. For control, use 1-1/2 pounds of toxaphene, 

 1-1/2 pounds of carbaryl (Sevin) , or 1 pound of trichlorfon (Dylox) --applied as a spray 

 over the row when damage is apparent. Cultivating after application will be helpful. 



Wireworms are damaging corn in a few fields where no insecticide had been used. If 

 replanting is necessary, apply a broadcast application of 2 pounds of aldrin or hep- 

 tachlor per acre, and disk-in immediately. A spray may give quicker kill than the 

 granules. It is difficult to control this insect after corn is planted. Use a spray 

 of aldrin or heptachlor to salvage a damaged stand where replanting is unnecessary 

 and to prevent further damage. Apply 1 pound of the actual chemical per acre. Direct 

 the spray at the base of the plant and cultivate immediately. Do not use aldrin or 

 heptachlor on dairy farms- -try diazinon. 



Corn rootworm eggs of both the western and northern species will begin to hatch within 

 another week or two. Potentially, fields of continuous corn in the northern half of 

 Illinois may be affected. Many fields of second-year corn north and west of a line 

 from Dixon to Peoria to Stronghurst may be damaged by the western corn rootworm . 

 Other fields of second-year corn to the east and north of this line may also be dam- 

 aged. The northern corn rootworm is most abundant north of Highway 36 (Pittsfield 

 to Springfield to Decatur), and is often a problem in fields where corn has been 

 grown continuously for three or more years in the same field. 



