Second -generation European corn borer pupation is more than 50 percent complete 

 in northern Illinois with peak moth emergence and egg laying occurring this coming 

 week in that section of the state. Egg laying should be at its peak in the western 

 section of the state. Damage by corn borers is expected in many fields in both 

 the northwest and west sections of the state. Treatments for second-generation 

 corn borer should be applied at first egg hatch, if there is an average of one or 

 more egg masses per plant. Use 1 pound of actual diazinon or 1 1/2 pounds of 

 actual carbaryl (Sevin) per acre as granules or sprays. Granules are best if 

 treatment is applied by air. When using diazinon, allow 10 days before making 

 ensilage or stover; carbaryl has no waiting period. 



Corn leaf aphid numbers are declining in most areas of the state, especially in 

 fields where tassels have emerged and pollen shed is complete. Aphids can be 

 found in occasional late-planted fields where a few tassels are emerging. 



Treatment is justified for corn in the whorl stage if 50 percent or more of the 

 plants have some aphids with a few tassels severely infested. Treatment in the 

 early tassel to pollinating stage is justified if 15 percent or more of the plants 

 are heavily loaded with aphids . 



Armyworms are present in some grassy areas in fields in northern Illinois. These 

 worms are over half -grown, and as many as 40 per square foot were found in a 

 grassy area. Late oat fields and grassy cornfields in the northern section should 

 be watched for armyworms during the next week. If needed, carbaryl (Sevin) at 

 1 1/2 pounds of actual insecticide per acre, as a spray, will give control. Toxa- 

 phene at 1 1/2 pounds actual per acre can also be used on corn grown for grain 

 and not ensilage. 



Simyra henrici , an orange and brown spiny caterpillar, is present in some corn- 

 fields . It feeds on the leaves of corn. Another caterpillar, the wooly bear 

 caterpillar , is still present in varying numbers in many cornfields'! It feeds 

 on fresh silks and may reduce kernel set. Treatment may be justified in late- 

 planted corn with less than 90 percent silk where there is severe feeding on the 

 silks. If caterpillars are numerous, treatment may be justified. Apply 1 1/2 

 pounds of carbaryl (Sevin) or toxaphene per acre for control. Toxaphene should 

 be used only if corn is to be used for grain. 



Homeowner Insect Problems 



Write grubs can be prevented in new-seeded lawns by treating the soil with chlor- 

 dane before seeding. Apply 20 ounces of actual chlordane per 10,000 square feet 

 of lawn area and mix into the soil. This treatment will protect against grubs 

 for five years. 



Sod webworm larvae could be present in some lawns this week. These larvae are 

 gray with small brown spots over their body and have a black head. The worms 

 live in silken-lined burrows in the thatch of the lawn and clip off grass blades 

 at the base of the plant. 



To control sod webworms, apply as a spray: (a) 2 pounds of actual carbaryl (Sevin), 

 (b) 1 pound of diazinon, or (c) 1 1/4 pounds of trichlorfon (Dylox) per 10,000 

 square feet (1/4 acre) . Apply the amount of insecticide suggested in at least 

 25 gallons of water, and do not water the lawn for 3 days after treatment. Gran- 

 ular forms of the same insecticides applied from a fertilizer spreader can be 

 used in place of the spray. 



