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INSECT 



SURVEY 



BULLETIN 



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College of Agriculture 



University of Illinois 



and Natural History Survey, Urbana, Illinois 



ate / County / Local Groups / U. S. Department of Agriculture Cooperating 



FOR IMMEDIATE RELEASE 



May 10, 1968 



INSECT SURVEY BULLETIN NO. 9 



This series of weekly bulletins provides a general look at the pest situation 

 (fruit and commercial vegetables excepted) , along with suggested, abbreviated 

 control measures . Each individual should check his own fields to determine lo- 

 cal conditions . The plant disease report was prepared, by the Illinois Natural 

 History Survey, the insect situation by the Department of Agricultural Entomol- 

 ogy and the Illinois Natural History Survey, and the weed report by the Depart- 

 ment of Horticulture . 



FIELD CROP PEST PROBLEMS 



Forage Crops 



The alfalfa weevil continues to hold the spotlight. Economic damage is occurring 

 in most alfalfa fields south of Route 40, while north of this line feeding is 

 noticeable but only an occasional field has required treatment. In some fields 

 south of Route 50, larval populations have doubled from what they were last week, 

 but many larvae are pupating. Most fields south of Route 40 have been treated 

 once and some have had two spray applications. In general, insecticide treatments 

 have been effective in this heavily infested area. 



In the area north of Route 40 and south of a line from Watseka to Hardin an occa- 

 sional field may need treatment during the week of May 13. 



In some problem fields where at least 25 percent of the plant terminals show feed- 

 ing, apply an insecticide. But in many of the current problem fields it would be 

 best to cut the alfalfa if flower buds are showing, remove the hay, and spray the 

 second growth. After cutting the first crop, watch the new growth. If weevil 

 damage can be seen and larvae are present, spray immediately. 



The insecticide recommendations are: 



1. Experienced commercial applicators who have the proper protective clothing will 

 get the best results with methyl parathion applied at 1/2 pound per acre, or 



a special alfalfa weevil spray of azinphosmethyl (Guthion) at 1/2 pound per 

 acre. Azinphosmethyl can be applied only once per cutting . Do not harvest 

 for 15 days after treatment with methyl parathion, or for 16 days after apply- 

 ing azinphosmethyl. 



2. The person not properly equipped with protective clothing to use methyl para - 

 thion or azinphosmethyl can use a mixture of 5/4 pound of malathion and 



3/4 pound of methoxychlor per acre (3 pints of a concentrate containing 



