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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. Allow 10 days between treatment and the ensiling of corn 

 when applying diazinon; carbaryl has no waiting period. Commercial applicators may pre- 

 fer to use parathion at 1/2 pound actual per acre, which will provide good control of 

 the com borer. Parathion has a 12 -day waiting period between treatment and harvest. 



Corn rootworm eggs will be hatching soon. If you know or suspect that you have a root- 

 worm problem and did not use an organic phosphate or carbamate insecticide at planting 

 time, apply one of the recommended chemicals now as a basal treatment. Do not wait to 

 count larvae. In many fields --especially early planted ones --the corn will be too tall 

 for a basal treatment by the time rootworms are large enough to be found and counted. 



Insecticides suggested for basal treatment are diazinon, phorate (Thimet) , BUXten, di- 

 sulfoton (DiSyston) , or parathion (Niran)--at the rate of 1 pound of actual chemical 

 per acre, and carbaryl (Sevin) a t the rate of 2 pounds actual per acre. 



Black cutworm damage is still being reported in various locations in Illinois. Check 

 cornfields For areas of missing plants, especially in the low spots. If plants are 

 being cut above the growing point of the corn and if the worms are all over 1 inch long, 

 the outbreak will be over very shortly, and the corn will continue to grow. However, 

 you should treat immediately if the plants are being cut off below the growing point 

 and many worms are less than an inch long. Direct the spray at the base of the plants; 

 use carbaryl (Sevin) at 2 or 3 pounds, diazinon at 2 pounds, toxaphene at 3 pounds, or 

 trichlorfon (Dylox) at 1 pound of actual chemical per acre in at least 20 gallons of 

 water per acre; also, cover the spray by throwing soil at the base of the plants with 

 a cultivator. 



Billbugs damage to young com stands has been observed. They are snout beetles that 

 drill holes in stalks below ground level. When the leaves emerge, they have a series 

 of holes in them. The feeding of a single beetle may kill a small plant, while a 

 larger plant may continue to grow normally with only a few rows of holes across the 

 leaves. Suckering and distorted growth are other symptoms of billbug injury. 



White grub damage has been reported in both corn and soybeans. These grubs have hatched 

 in 1968 or 1967 from eggs laid by June beetles. Half -grown grubs will continue to feed 

 all summer. Full-grown grubs will soon pupate and quit feeding. There is no effective 

 chemical control for grubs in a soybean field after the plants are up. In a cornfield, 

 some control can be obtained with 1 pound actual of aldrin or heptachlor, applied as a 

 spray to the base of the plant and cultivated-in immediately. Do not use aldrin or 

 heptachlor on a soybean field . 



Common stalk borers are moving out of grasses and weeds into border rows of corn. These 

 whitish-brown, striped worms with a purple band around their middle feed in the whorl of 

 the corn plant. Emerging leaves have irregular holes in them. Plants may be killed or 

 severely damaged by this pest. Chemical control is difficult to achieve because the 

 borers are usually too deep in the whorl of the plant for insecticides to reach them. 



FORAGE INSECTS 



Alfalfa weevil activity is about over . Continue to watch for damage to the new growth 

 of second-crop alfalfa north of a line from Jacksonville to Watseka. If the field does 

 not green-up soon after the first cutting, treat it promptly. Larvae are present in 

 fields in this area, but pupation and adult emergence is progressing rapidly. 



