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Canners should examine sweet corn, this week, as treatment may he necessary 

 starting the week of June 25. For the next three weeks, carefully observe any 

 fields with a tassel ratio of 20 or more. 



Market growers in the northern half of Illinois should plan to start in- 

 secticide treatments for borer control this week (June 19). 



Armyworms became evident in some areas in the southern half of Illinois 

 this past week. In many areas the worms have now practically matured, the damage 

 is done, and it is too late to profitably apply insecticides. In other areas small 

 worms are still numerous, and in these cases control may still be profitable. 

 Farther north, worms are smaller and damage is not yet evident. When the worms are 

 predominantly only half to two-thirds mature, control will be profitable. Continue 

 to examine rank stands of grains and grasses for the next ten days. If there are 

 six or more worms per linear foot, or 12 or more per square foot, treatment is 

 advised. Smaller populations can be serious if they begin to cut grain heads. 



To control, apply 1 1/2 pounds of toxaphene or l/k pound of dieldrin per 

 acre for small grains. Allow J days between treatment with dieldrin and harvest, 

 and 7 days for toxaphene on wheat, but lU days on barley. For beef pastures, use 

 toxaphene; allow k2 days between last grazing on treated pastures and slaughter, 

 particularly if toxaphene is being used on the animals to control flies. For dairy 

 pastures, use 2 pounds of methoxychlor or 1 pound of malathion per acre, but do not 

 graze for one week after treatment. 



Cutworms are maturing rapidly and the damage to corn is about over. The 

 cutworm moths from this generation are starting to emerge. They probably will mi- 

 grate north, but may remain here to lay eggs. A later outbreak is therefore pos- 

 sible. 



Grape colaspis damage may appear this week to corn and soybeans planted 

 on clover sods or after two years of beans. These tiny, comma-shaped grubs eat the 

 root hairs and may scar the main root. Damaged corn turns purple, and beans turn 

 yellow. Yields are reduced, but rarely is damage so severe that replanting is 

 warranted. Control measures are not effective this late. 



Grasshoppers are hatching in the southern half of Illinois. Control these 

 infestations while the grasshoppers are still concentrated in the fence rows, ditch 

 banks, and grass waterways. Use 1/8 to l/U pound of dieldrin or 1 to 1 1/2 pounds 

 of toxaphene per acre. Do not apply dieldrin to pastures grazed by dairy cattle or 

 animals being finished for slaughter. Toxaphene cannot be used on dairy pastures; 

 it can be applied to pastures for beef animals, but not within h2 days of slaughter. 



Pea aphids are present on second-growth alfalfa and clovers, but not to 

 the extent that they were a few weeks ago. Weather conditions will determine their 

 importance. Warm, muggy weather enabling a fungus disease to spread rapidly would 

 reduce aphid numbers drastically. New growth can be sprayed with 1 pound of mala^- 

 thion to within one week of harvest or with \/h pound of lindane to within 28 days 

 of harvest. If new seedings in grain fields are being seriously attacked, use 

 malathion to within one week of grain harvest. 



Flea beetles are decreasing in number, and the next generation will appear 

 in late July and early August. Corn is now rapidly growing away from the damage of 

 the past few weeks. 



