141 7 



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/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 



FOR IMMEDIATE RELEASE 



No. 8, May 22, 1970 



This series of weekly bulletins provides a general look at the insect, weed, and 



plant disease situation (fruit and commercial vegetables excepted) , along with 



suggested abbreviated control measures. Each individual should check his own fields 



to determine local conditions. 



THE LIBRARY OF THE 



INSECTS 



FORAGE INSECTS 



JUN 18 1970 



UHIV&fcSltY Qt IfcUINOIS 

 AT UBIAN^eHAMPAIGN 



Alfalfa weevil populations continue high in fields south of State Highway 17. 

 Damage is moderate to severe in fields south of U.S. Highway 40. Most fields in 

 this area have been sprayed at least once; in some fields damage to the second 

 crop is already severe and treatment is needed. Although the number of weevils is 

 high, it has leveled off and is beginning to decline, as the pupation of the larvae 

 continues and as the wasp parasites take their toll. 



In the area between highway 40 and 17, damage is light to moderate; most fields are 

 close to harvest. Cutting alone, especially when temperatures are high, will reduce 

 the number of worms, but watch the new growth closely. If it does not green-up 

 within 2 to 4 days and worms are present, apply a treatment promptly. The number 

 of worms is likely to remain high for another week or two in this area. 



North of State Highway 17, feeding is noticeable but is not of economic importance. 

 Some fields may need treatment within a week or two. The greatest chance of injury 

 could be on the new growth of the second crop. 



The insecticide recommendations are: 



Commercial applicators . Apply 1/2 pound per acre of methyl parathion or 

 azinphosmethyl (Guthion) . Use azinphosmethyl only once per cutting. Do not 

 harvest for 15 days after treatment with methyl parathion, or 16 days for 

 azinphosmethyl. Wear protective clothing. 



Persons not equipped with protective clothing . Use (1) Imidan at 1 pound per 

 acre, (2) a mixture of 3/4 pound of malathion and 5/4 pound of methoxychlor 

 per acre, (5) a mixture containing at least 1/2 pound of diazinon and 1 pound 

 of methoxychlor per acre, or (4) 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 Imidan, methoxychlor, diazinon, 

 or mixtures of them. There is no waiting period for malathion. Do not apply 

 Imidan more than once per cutting. 



