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To decide whether an insecticide can be profitably applied, measure the 

 tassel ratio of the field and count the percent of plants with recent whorl leaf 

 feeding. To determine the tassel ratio, measure the height of the plant with 

 leaves extended; split the stalk open and measure from the tip of the developing 

 tassel to the base of the plant. Divide the tassel height by the plant height, 

 and multiply by 100. This figure is the tassel ratio. If the tassel ratio is at 

 least 35 (preferably Uo to 1*5) and at least 75 percent of the plants show recent 

 whorl feeding, then treatment is justified. Use 1 pound of actual diazinon in 

 granular form per acre or 1 1/2 pounds of carbaryl (Sevin) as granules. For 

 spraying, use the same amount of actual insecticide per acre, and direct the spray 

 to the upper third of the plant. Aerial applications should be granules, not 

 sprays or dusts. Follow the label precautions in harvesting and feeding treated 

 corn. 



Corn flea beetles are feeding on corn in the southern half of Illinois 

 and are becoming progressively more numerous southwards. No economic damage was 

 observed this week. 



Stored grain insect s are usually a problem in stored wheat. Before 

 wheat harvest begins, sweep up and clean out all old grain and other debris from 

 inside and around the bin. Then spray all inside surfaces to runoff with 1.5 per- 

 cent premium-grade malathion or 2.5 percent methoxychlor . Also treat the wheat, 

 as it is being binned, with a liquid or dust form of premium-grade malathion. 

 These three steps will insure insect-free wheat for a year or more. 



Horn flies are abundant on cattle in the southern one-third of Illinois. 

 Apply Ciodrin sprays to dairy cows and either Ciodrin or toxaphene sprays to non- 

 dairy cattle to control flies. 



Upcoming Farm Insect Problems 



Grasshoppers are hatching, but timely rains may be killing them. We 

 did not see any population this week that might pose a problem. 



Thrips are abundant in cornfields. They can be found by unrolling the 

 whorl leaves of the plants. The black, orange or yellow, rapidly moving insects 

 about l/l6 inch long are thrips that scar the leaf, giving it a silvery appear- 

 ance. With ample moisture, this pest is not damaging. If the weather turns dry, 

 thrips can cause damage. Use either toxaphene or carbaryl as a spray. 



Armyworms of the present generation are beginning to emerge as moths in 

 the southern one-half of Illinois. They will fly northward and deposit eggs in 

 grassy cornfields. Observe such cornfields in the northern one-third of the state 

 about July 5-10 for armyworms feeding on the grass and on the corn. 



Corn borer moths are just beginning to lay eggs in the northern one-half 

 of Illinois. At present, we do not anticipate a problem in the central one-third. 

 It would be wise to check the more advanced fields in the northern section about 

 July 1 for indications of treatment need. 



The Homeowner's Insect Problems 



Striped cucumber beetles are numerous on squash, cucumber, melon and 

 other vine crops in home gardens. These black and yellow striped beetles feed 

 upon the new seedlings as they emerge from the soil. They commonly kill the small 



