1-/K / 



COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA -CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA. ILLINOIS 



NSECT, WEED & PLANT DISEASE-SURVEY BULLETIN 



TATE/COUNTY/LOCAL GROUPS/US DEPARTMEMT OF AGRICULTURE COOPERATING 



IR IMMEDIATE RELEASE 



»..,ia 



No. 9, May 23, 1969 



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is series of weekly bulletins -provides a general look az the insect, weed, and -giant 

 sease situation (fruit and commercial vegetables excepted) , along with suggested, ab- 

 'eviated control measures. Each individual should check his own fields to determine 

 <cal conditions . 



INSECTS 



)RAGE INSECTS 



.falfa weevil populations remain high . Moderate to serious damage is evident in untreated 

 .elds south of Route 16. Terminal feeding by larvae ranged from 40 to 100 percent in this 

 •ea this past week. Damage has reached economic levels in many alfalfa fields between 

 >utes 16 and 136. Treatments should be made now or else the hay should be cut and removed, 

 .elds between Routes 136 and 24 should be watched closely during the coming week. 



l the extreme southern areas of the state, the number of larvae is gradually leveling off, 

 ren declining, as pupation increases and new adults emerge. Parasitism of the larvae by 

 isps should also help keep populations in check. 



)ntinue to watch alfalfa fields in the southern two -thirds of the state for weevil prob- 

 >ms. If the alfalfa is near cutting, remove the hay and watch the new growth for damage. 



iny fields south of Route 50 have been sprayed at least one time. In some instances, the 

 image to the new growth is already extensive with as many as 10 to 20 worms present per 

 reep. If the crop has already been cut but the new growth has not been sprayed, watch it 

 .osely. If it does not green-up in 2 to 4 days and if worms are still present, apply an 

 lsecticide as soon as 25 percent of the terminals show noticeable feeding. 



le insecticide recommendations are: 



Commercial applicators can apply 1/2 pound per acre of methyl parathion or azinphos- 

 methyl (Guthion) with good results . Use azinphosmethyl only once per cutting . Do not 

 harvest for 15 days after treatment with methyl parathion, 16 days for azinphosmethyl. 

 Wear protective clothing. 



Persons not equipped with protective clothing can use a mixture of (1) 3/4 pound of 

 malathion and 3/4 pound of methoxychlor per acre , (2) a mixture containing at least 

 1/2 pound of diazinon and 1 pound of methoxychlor per acre, or (3) 1-1/4 pounds of 

 malathion per acre on days when air temperatures will be above 60° F. for several 

 hours after application. Do not harvest for 7 days after treatment with methoxychlor, 

 diazinon, or mixtures of them. There is no waiting period for malathion. 



Fields that are close to harvest and in which treatment is necessary should not be 

 treated with azinphosmethyl (at least 16 days before cutting) or with methyl parathion 

 (15 days). Switch to one of the other suggested chemicals, such as malathion, that 

 has no waiting period. 



e no less than 4 gallons of finished spray per acre by air, or 20 gallons per acre if 

 •ound equipment is used. On stubble, 10 gallons per acre is sufficient. 



