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Cooperative Extension Service, University of 

 Illinois College of Agriculture in Cooperation With 

 the Illinois Natural History Survey and U.S.D.A. 



FOR IMMEDIATE RELEASE May 27, 1966 



INSECT SURVEY BULLETIN NO. 6 



This sixth weekly bulletin on the general insect situation in Illinois 

 (fruit insects excepted), prepared by entomologists of the University of Illinois 

 College of Agriculture, Illinois Natural History Survey and cooperating agencies, 

 reports general trends in insect activity and suggests abbreviated control meas- 

 ures. Each individual should check his own fields to determine local conditions. 



Present Farm Insect Problems 



Alfalfa weevil larvae are decreasing as they pupate. They will soon 

 emerge as adults. Damage will continue for about two weeks yet, but will then 

 decline rapidly. 



In general, it is now too late to spray first-growth alfalfa. Cut it, 

 remove the hay and spray the new growth immediately. Use malathion or a commer- 

 cial mixture of diazinon and methoxychlor. Allow one week to elapse between ap- 

 plication and harvest when using diazinon or methoxychlor; no waiting period is 

 needed for malathion. Azinphosmethyl (Guthion) or methyl parathion can be used 

 for weevil control by those equipped to follow safety precautions for personal 

 protection when handling and applying the more toxic insecticides. 



Wireworms have begun to damage some cornfields not treated with aldrin 

 or heptachlor at or before planting. The round, wirelike, brown, hard-shelled 

 worms hollow out seeds or drill holes in the base of stalks, causing death of the 

 plant. 



Little can be done now to protect these plantings. Occasionally 1 1/2 

 pounds of actual aldrin or heptachlor in 20 gallons of water per acre as a spray 

 directed at the base of the plant will reduce the worm population enough to save 

 the stand. Cultivate immediately. 



If the stand is lost, apply 2 pounds of aldrin or heptachlor per acre, 

 disk in immediately and replant. A spray may give quicker kill than granules. 

 Do not apply when drift occurs. 



Black cutworms are still an unknown quantity. For the next three weeks, 

 inspect low spots in cornfields regularly. If corn plants are being cut off and 

 worms are still small, apply 3 pounds of toxaphene per acre and direct the spray 

 at the base of the plants. Cultivate immediately to cover the spray deposit. On 

 dairy farms, use 2 pounds of carbaryl (Sevin) per acre. This treatment will help 

 to control small worms but will not kill the large cutworms . 



Sod webworms feed on corn after grass sods; they closely resemble black 

 cutworms. Examination of the worm will reveal small black spots on the grey body. 

 In general, they are lighter colored than black cutworms. They also spin a web. 

 Aldrin and heptachlor do not control this pest. It may be necessary to apply 

 1 pound of carbaryl (Sevin) as a spray, directed at the base of the plant. 



Armyworms are reported to be abundant in some fields of wheat, but they 

 are still small. Check fields carefully to determine need for control before mak- 

 ing any application. 



