Pupation of overwintering European corn borers is complete in southern Il- 

 linois, ranges from 50 to 90$ complete in central Illinois, and from 25 to 70$ com- 

 plete in northern Illinois. Moth emergence is well underway in southern Illinois and 

 has begun in central Illinois. No moth emergence has been recorded in northern Illi- 

 nois as yet. Some death of overwintering borers was noted this week. 



Borer development is similar to previous years and development of corn is 

 slightly later. However, we will have to be alert to this pest in about four weeks. 



Leafhoppers are present in greater numbers in alfalfa fields this year than 

 they have been for several years. These pests migrate into Illinois. The exact area 

 of heaviest infestation has not been determined but it is generally a wedge-shaped 

 area in the central part of the state. 



Wireworms and sod webworms have been reported damaging small corn plants. 



Horn fly numbers on pastured cattle increased rapidly this week. Several 

 hundred horn flies per animal was common. Stable flies and face flies were present, 

 but in low numbers. 



For beef cattle, a 0.5$ toxaphene water-base spray every three to four 

 weeks is effective against horn flies. A backrubber containing 5.0$ toxaphene in 

 oil is also generally effective. Allow 28 days between treatment with toxaphene and 

 slaughter of the animals. 



For dairy cattle, use 2.0$ ciodrin, 0.1$ pyrethrin, or 1.0$ DDVP oil-base 

 spray at 1-2 ounces per animal as needed. 



Bees needed for pollination can be killed with pesticides. Do not apply 

 pesticides during mid-day to crops being pollinated by bees. 



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

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

 nate 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 coop- 

 eration with the USDA Agricultural Service, Plant Pest Control Branch, from informa- 

 tion gathered by entomologists and cooperators who send in weekly reports from their 

 own localities. 



