COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT WEED & PLANT DISEASE SURVEY BULLETIN 



STATE/COUNTY/LOCAL GROUPS/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 



FOR IMMEDIATE RELEASE 



No. 12, June 8, 1973 



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 



Black cutworms are damaging corn in some areas , but infestations are not as serious 

 as last year. The worms are still only about half grown (3/4 of an inch) , and will 

 feed for another seven to ten days. The cutworms are working closer to the soil sur- 

 face because of wet conditions, and the corn is still small. Most of the plants are 

 being cut above the growing point, and these plants will recover. 



Corn fields should be watched closely during the next two weeks for cutworm damage. 

 If the worms are still small and you find 1 or more per 25 plants, apply controls im- 

 mediately. 



For control, broadcast 20 pounds of 5 -percent carbaryl (Sevin) bait per acre. A spray 

 of 2 pounds of carbaryl and 2 quarts of molasses plus water per acre banded at the 

 base of the plants is also effective. Commercially prepared spray baits containing 

 carbaryl plus Tractum or molasses are available. Trichlorfon (Dylox) at 1 pound per 

 acre as a spray will control black cutworms. Use 20 gallons of water per acre when 

 band-spraying with trichlorfon, then cultivate in order to throw soil over this band 

 in the row. 



If replanting is necessary and if the majority of the cutworms are once more of small 

 size (less than 1-1/2 inches), they could seriously damage the new planting. In that 

 case, apply 5 -percent carbaryl (Sevin) bait at 10 pounds per acre as a band over the 

 row behind the press wheel when planting. If most of the worms are 1-1/2 to 1-3/4 

 inches or larger, the corn can be replanted without using an insecticide treatment. 



Wireworms are causing damage in a few fields of corn. Wilting plants are an indica- 

 tion of wireworms. Examine the stalk just below ground level. If a hole has been 

 drilled into it, sift the surrounding soil for this hard-shelled, reddish-brown, wire- 

 like worm. 



There is no proven way of controlling wireworms after the problem occurs. On a trial 

 basis only (to protect the stand from further damage), apply 1 pound of actual Dyfo- 

 nate or Thimet per acre as granules placed at the base of the plants. Cover with cul- 

 tivation. A rain following treatment would improve the chances of success. If re- 

 planting becomes necessary, apply one Dyfonate or Thimet in a 7 -inch band ahead of the 

 press wheel. This will protect the plants against all but the full-grown wireworms. 



