-2- 



July 10 in northern Illinois. This year, however, the overwintering borer popula- 

 tion is lower than it was in 1956. Observe the more advanced fields for the next 

 three or four weeks. 



Bean leaf beetle is attacking soybeans, in some instances, just as they 

 are emerging from the ground. If stands are being noticeably reduced from beetles 

 killing the plants, apply 1 1/2 pounds of DDT, l/4 pound of dieldrin or 1 l/2 pounds 

 of toxaphene per acre. 



Pea aphids continue to be present throughout the northern two- thirds of the 

 state, but by far the highest concentrations are in the northern third. Many of the aphids 

 are developing wings and migrating to other crops. Parasites, predators and aphid 

 diseases are abundant in some fields and scarce in others but over all are helping 

 to check aphid populations throughout the state. 



It is too close to harvest to use insecticides except for 1 pound of mala- 

 thion, which requires one week between treatment and harvest or pasture. The best 

 suggestion is to cut the hay crop now, salvage what can be used and then spray the 

 new growth if the aphids continue. Lindane, 0.3 pound per acre, can be used at 

 that time, as well as malathion. Allow one month to elapse between treatment with 

 lindane and harvest. 



Watch new seedings closely, as aphids are migrating into them and can 

 quickly kill these tender plants. Malathion can be used for new seedings within 

 one week of grain harvest. Lindane should not be applied after grain heads start 

 to form. 



Potato leafhoppers migrated into Illinois this past week, concentrating 

 in an area north of a line from Quincy to Lawrenceville. Although the infestations 

 are spotted throughout this area, the highest populations are in central Illinois. 

 Leafhoppers are the tiny, light-green, wedge-shaped insects that attack second- 

 growth alfalfa; the alfalfa turns yellow, is stunted, and hay quality is seriously 

 affected. Damage from this pest may be greater than it has been over the past few 

 years. Examine second growth carefully and if these leafhoppers are numerous, 

 apply 1 pound of methoxychlor per acre. It is too late to treat after damage be- 

 comes evident, as the plants will not recover from the feeding of these leafhoppers. 



Face flies are present in economic numbers in the area north of a line 

 from St. Louis to Paris. Apply control measures now. 



Ca ution : Before applying insecticides, read labels carefully and follow 

 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, Illinois Agricultural Ex- 

 tension Service and Illinois Natural History Survey, in cooperation with the USDA 

 Agricultural Service, Plant Pest Control Branch, from information gathered by ento- 

 mologists and cooperators who send in weekly reports from their own localities. 



HBP:bb 

 6/9/61 



