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appear in the most heavily infested fields. These insects eat aphids . The popu- 

 lation should reach a peak in about two weeks and thus help to bring the aphid 

 populations under control. 



If moderate to severe aphid infestations are present when the tassels 

 first appear, control may pay. We recommend 1 1/k pounds of malathion per acre or 

 1 pound of diazinon. Allow 10 days between application and harvest when applying 

 malathion. Diazinon sprays can be applied until the day of harvest. Remember 

 that these sprays will reduce the beneficial insect populations. Thus, if lady 

 beetles and similar insects are present in numbers, it may not be wise to spray. 



Some persons have been asked about using carbaryl (Sevin) to control 

 aphids. Do not use it for this purpose, as it is toxic to beneficial insects and 

 ineffective for controlling corn leaf aphids. 



European corn borer moths are emerging as far north as Highway 6, and 

 egg laying has started. Egg hatch was reported in one locality in north-central 

 Illinois. This is about a week earlier than anticipated. General opinion is that 

 corn borer numbers will be greater this year than last. Furthermore, the moth 

 emergence may extend over a longer period than the first generation did. Thus we 

 could have extensive egg laying for the next four weeks. 



To decide whether to apply an insecticide to field corn, count egg masses 

 per plant. If the average is one or more per plant, applications may be profitable. 

 Use 1 1/2 pounds of carbaryl ( Sevin) or 1 pound of diazinon per acre as granules, 

 applied by air or ground equipment. They will be equally effective. Sprays ap- 

 plied by ground machines will be as effective as granules in borer control, but 

 sprays applied by airplane will be somewhat less effective. 



Sweet corn growers should be alert to the borer situation and should fol- 

 low the recommended treatment schedules if egg counts warrant. 



Northern corn rootworm adults are present in many fields, particularly 

 in the northern third of Illinois. They feed on silks. If pollination has occurred, 

 forget these beetles for this year. If a few silks are appearing and beetles aver- 

 age 10 or more per plant, an application of 1 pound of carbaryl per acre may be 

 profitable. This would also help to control corn borer. If aphids are present, 

 use diazinon to control rootworm, the aphids, and corn borer. 



Alfalfa webworms are light green to gray with black spots. They are 

 feeding extensively on soybeans in southern and western Illinois. If growing 

 conditions return to normal, soybeans will recuperate from moderate damage. We 

 have no "rule of thumb" measurement for determining need for control under present 

 conditions. If defoliation appears to be important, use 1 1/2 pounds of toxaphene 

 per acre. Do not use carbaryl in soybeans in this area, as it could accelerate the 

 red spider mite problem. 



Woolly bears are now feeding on silks in cornfields. Ordinarily they 

 are not important unless they are extremely abundant and are interfering with pol- 

 lination. This they rarely do, and even then chemical control is not required. 



Armyworms , as expected, are now appearing in some cornfields in north- 

 central and northern Illinois. If corn is being stripped, a spray of carbaryl 

 should provide control. 



