Ih 7 



COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA -CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA. ILLINOIS 



NSECT WEED & PLANT DISEASE SURVEY BULLETIN 



ATE/COUNTY/LOCAL GROUPS/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 



FOR IMMEDIATE RELEASE 



No. 4, April 24, 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 



JUN 1 8 1970 



FORAGE INSECTS 



UNIVfeRSIIY Ot= ILLINOIS 

 AT UBBANA-GHAMPAIGN 



Alfalfa weevil populations are still low and the alfalfa seems to be growing. Because 

 of the lower number of weevils and good plant growth, perhaps no insecticide applica- 

 tions will be needed in many fields. Each field should be examined frequently, however. 



In southern Illinois, south of Harrisburg, small- to medium-sized larvae were present 

 this week. Some adults are still laying eggs. It is now time to examine fields care- 

 fully and decide whether you need an insecticide for weevil control. Continue this 

 alert for at least two more weeks. 



In south-central Illinois, some larvae are present. Adult weevils are easy to find, 

 but feeding is hardly noticeable. Treatment, if necessary, will probablynot be needed 

 for one to two weeks, so begin to check fields this coming week. 



In central Illinois, occasional larvae can be found, but adults are much more common. 

 Weevil feeding is not yet noticeable. Treatment, if needed, will not be for two to 

 three weeks . 



When there is feeding on 25 percent or more of the terminals and the field is more than 

 two weeks from harvest, an insecticide application may be justified. 



The insecticide recommendations are : 



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

 methyl (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. 



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



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



(3) 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 



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. 



