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COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT WEED & PL ANT DISEASE SURVEY BULLETIN 



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



FOR IMMEDIATE RELEASE 



No. 9, May 28, 1971 



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 determine local conditions. 



INSECTS 











CORN INSECTS 



Black cutworms. More reports of damage were received this week from several sec- 

 tions, mostly in western Illinois. So far, the damage is confined to a relatively 

 few cornfields , but is severe. The size of worms ranges from a half inch or less 

 to almost two inches in length. Worms that are one-half to one inch long will 

 continue to feed for another week to ten days. When the worms reach two inches 

 in size, feeding is virtually completed and pupation will occur shortly. 



Cornfields should be carefully examined now for cut or missing plants --signs that 

 cutworms are at work. Damage has been observed on hillsides as well as low, wet 

 areas in fields. 



If damage is apparent, corn that is cut off above the growing point will usually 

 recuperate, but plants cut off below the growing point are killed. If the corn 

 is small, (2 to 4 inches high), cutting generally occurs above the growing point. 

 About half of these plants could be expected to recover. Take this possible re- 

 growth factor into consideration before disking-up a field and replanting. Im- 

 mediate treatment is needed if many of the worms are less than an inch long and 

 plants are being cut off below the growing point. 



For emergency control of cutworms, consider using one of the following treatments; 



1. A pellet- like bait of 5-percent carbaryl (Sevin) on apple pomace, applied 

 broadcast at 20 pounds per acre with ground equipment or from the air. Do 

 not cover by cultivation . 



2. A liquid bait using molasses or Tractum with carbaryl, applied as a spray 

 directed as a band over the plants or at their base at the rate of 2 pounds 

 per acre" ! The best coverage will be obtained with 20 gallons of water and 1 

 or 2 quarts of molasses per acre. Do not cultivate immediately; but if the 

 soil is dry, covering the carbaryl -molasses spray by cultivation may improve 

 control. Do not use the sugar baits near bee hives. 



3. Trichlorfon (Dylox) , applied at 1 pound per acre in at least 20 gallons of 

 water as a spray directed at the base of the plant, will also provide con- 

 trol. Cover the trichlorfon spray band by throwing the soil at the base of 

 the plants with a cultivator. 



