-2- 



Grasshoppers can be found in numbers in fence rovs, ditch banks, grass 

 waterways and similar areas. An occasional hay crop field also has large numbers 

 of small 'hoppers. 



If control is necessary, use as sprays carbaryl (Sevin) at 3A pound per acre, 

 diazinon at 1/2 pound, malathion at 1 pound or naled (Dibrom) at 3A pound per 

 acre. When treating forage crop fields, allow 10 days between treating and harvest 

 with diazinon and four days with naled. There is no waiting period for carbaryl or 

 malathion. 



Armyworms can be found in small numbers in occasional grassy cornfields 

 in northern Illinois. A few can also be found in grass-legume hay fields. These 

 worms are up to one-half inch long. 



In general, the high temperatures do not favor armyworms. If a problem 

 develops, it will be within the next week, but even then only an occasional field 

 will be affected. If insecticides are required on corn, carbaryl ( Sevin) can be 

 used on all corn or toxaphene on grain but not on ensilage corn. 



Spotted alfalfa aphids can be found commonly in alfalfa fields on the west 

 side of the state from southern to northern Illinois. These small yellow aphids 

 with black spots feed on the lower leaves and stems of the alfalfa plants. The 

 plants wilt, turn yellow and die. Check alfalfa fields, particularly those on sandy 

 or light soils. 



If the infestation approaches the damaging stage, use l/k pound of deme- 

 ton, 1 pound of diazinon, 1 l/k pounds of malathion or l/k to 1/2 pound of methyl 

 parathion. Demeton and methyl parathion should be applied only by experienced op- 

 erators equipped with the proper protective clothing. Malathion can be used on hay 

 crops with no interval between application and harvest. Diazinon requires 10 days 

 and methyl parathion 15 days; demeton requires 21 days, and only one application 

 per cutting is permitted. 



Potato leafhopper damage to alfalfa is now becoming evident. Some fields 

 are turning yellow. This condition has been observed as far north as Route 30 in 

 northern Illinois. Examine alfalfa plants for leaf hoppers by shaking a plant over 

 a plate. If you find lots of tiny, green, wedge-shaped insects that run sideways 

 but do not yet have wings, apply 1 pound of malathion or znethoxychlor to control 

 these leafhoppers. This control will help you produce quality hay. No time inter- 

 val between application and harvest is required with malathion, but one week is re- 

 quired when using methoxychlor . 



Fields in which the plants are already yellow and purple will not recover 

 from the damage until next growth. Thus clip and remove and then spray the new 

 growth . 



Yellow grass thrips were abundant in some soybean fields this week. These 

 thrips rasp the surface of the leaf, making silvery paths. When they are abundant, 

 the field may take on a silvery sheen. No control is recommended now. If control 

 becomes necessary, you can use toxaphene, malathion or several other insecticides. 



Upcoming Farm Insect Problems 



European corn borer may develop into a problem this year. Although the 

 first generation was not serious, it was present generally and some borers could be 

 found in most fields throughout the state. Thus the seed stock is present and prac- 

 tically all first-generation borers will pupate and provide moths for a second gen- 

 eration and eventually a third in southern Illinois. 



Northern corn rootworm larvae, which are generally present throughout the 

 northern half of Illinois, are maturing rapidly. Pupation varies from 25 to 75 per- 

 cent, and a few beetles have already emerged. In two or three weeks beetle popula- 

 tions will be at the peak, and the green beetles will be feeding on fresh silks. 



