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OR IMMEDIATE RELEASE May 8, I96U 



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INSECT SURVEY BULLETIN NO. h 



This is the fourth in a series of weekly bulletins on the general insect 

 situation in Illinois (fruit insects excepted), prepared by entomologists of the Uni- 

 versity of Illinois College of Agriculture, Illinois Natural History Survey and coop- 

 erating agencies. It is designed to forewarn people in Illinois of impending changes 

 in insect activity and to suggest abbreviated control measures. These reports indi- 

 cate only general trends. Each individual should check his own fields to determine 

 local conditions. 



Alfalfa weevil , sometimes considered the most serious insect pest of al- 

 falfa in the United States, was found in Illinois for the first time two weeks ago. 

 This insect, an imported one, has been present for many years in the western section 

 of the United States and for a dozen or more years in the eastern section. It was 

 present in Ohio and Kentucky last year, and then this spring the Missouri and Illi- 

 nois infestations were found. 



Weevils have been found in 13 of the counties south and east of a line from 

 Lawrenceville to Salem to Carbondale. Only a few have been found, but the infesta- 

 tion is so widespread that a suppression program would be hopeless. However, the 

 populations are so low that damage will not occur this year and individual farmers 

 would not profit from control measures. It will be a few years before this insect 

 increases enough to warrant control measures; but once the weevil is well established, 

 alfalfa hay production may be impossible unless control practices are carried on 

 faithfully. 



Spittlebugs have been observed, but not in large numbers. 



Potato leafhoppers are tiny wedge-shaped green insects, often referred to 

 as green gnats when they swarm out of alfalfa fields as they are being cut. These in- 

 sects winter in the southern United States, migrating northward in the spring. ^They 

 appeared in moderate numbers in Illinois this week, having migrated in on the high 

 winds. 



The feeding of this pest stunts alfalfa, which turns yellow to purple. No 

 control measures are recommended at this time. 



Face flies were observed on cattle this week. Dairymen can use 2.0$ ciodrin 

 in oil on their cattle. If automatic sprayers are used, beef cattle can also be 

 treated with ciodrin; otherwise, 5.0$ toxaphene in a backrubber will help to hold 

 face flies in check. Allow 28 days to elapse between treatment with toxaphene and 

 slaughter. 



Clover mites have been active for the past few weeks. These pests have win- 

 tered in the walls of the house and are now appearing outdoors as well as indoors. 

 They appear as tiny brown to red moving specks. To prevent reinfestation this fall, 

 remove the sod for a distance of at least 18 inches and preferably 2h inches all the 

 way around the house. Plant flowers and shrubs in this area. 



Caution ; Before applying insecticides, read the labels carefully and fol- 

 low all precautions. This not only will insure personal safety, but will also elimi- 

 nate insecticide residue hazards. 



This weekly report was prepared by H. B. Petty, Steve Moore and C. E. White, 

 Illinois Natural History Survey and Illinois College of Agriculture, in cooperation 

 with the USDA Agricultural Service, Plant Pest Control Branch, from information gath- 



