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COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT WEED & PLANT DISEASE SURVEY BULLETIN 



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



FOR IMMEDIATE RELEASE 



No. 2, April 14, 1972 



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. library of THE 



INSECTS 



APR 21 1972 



FORAGE INSECTS 



Alfalfa weevil infestations are developing rapidly. Damage to some fields may be 

 severe this year . Eggs , larvae , and adults can be found in all alfalfa fields 

 south of highway 50. 



Populations south of route 13 are at least as high as last year, and many fields 

 of alfalfa have far more than 25 -percent tip feeding. If the weather remains 

 warm, damage is expected to be quite severe within two weeks. Now is the time to 

 treat if you plan to do so. The need for a second insecticide application remains 

 to be seen. Egg-laying is continuing, and the adults are still numerous. However, 

 the early weevil feeding is usually more serious than that occurring later, when 

 early cutting can be used as a control method. 



From route 13 to route 50, damage will become apparent this week, particularly in 

 the western part. Populations are reported to be very high in some fields. In- 

 secticide applications will be timely this week (week of April 16) or early next 

 week, as indicated by counts in several fields. Depending on the degree of infes- 

 tation, another application may be needed later, if to control the larvae then 

 present is not possible. 



The insecticide recommendations are: 



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

 phosmethyl (Guthion) for good results. Use azinphosmethyl only once per cut- 

 ting, and do not harvest for 16 days. Do not harvest for 15 days after a 

 treatment with methyl parathion. As a general precaution, wear protective 

 clothing. 



Supracide, a new insecticide, can now be used to control alfalfa weevil. Do 

 not use within 10 days of harvest, and make only one foliar application per 

 cutting. Do not enter fields afterward on the day of application. For the 

 present, we list it for commercial applicators only. 



Persons not 



lot equipped with protective 

 ; (2) a mixture of 3/4 pound 



clothing . Use: (1) Imidan at 1 



of malathion and 3/4 pound of methoxy- 



pound 



per acre; 



chlor per acre; (3) a mixture containing at least 1/2 pound of diazinon and 

 1 pound of methoxychlor (Alfa-Tox) 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 



