FOB IMMEDIATE RELEASE May 11, 1962 



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 

 University of Illinois College of Agriculture, Illinois Natural History Survey and 

 cooperating agencies. These reports indicate only general trends. Check your own 

 fields to determine local conditions. 



Cl over leaf weevils are dying from a fungus disease that will increase 

 with warm weather. Most fields are rapidly growing away from weevil damage. It 

 is too late for profitable control. 



Pea aphid populations are generally low in alfalfa and red clover fields. 

 Warm, humid weather will promote the spread of fungus disease of aphids. Infected 

 or dead pea aphids are brown rather than bright green. Watch aphid numbers, par- 

 ticularly in the northern half of the state. Aphids survive best and increase 

 rapidly in cool weather. 



Spittlebug treatments must go on this week or not at all. Examine stems 

 and look closely behind leaf sheaths for these tiny yellow insects. If the aver- 

 age is at least one nymph per stem, consider using insecticides if you need all 

 the hay you can produce. One spittlebug per stem reduces yields of dry hay by 

 200 to 300 pounds per acre. The higher the spittlebug count, the greater the ex- 

 pected loss. If control is necessary, apply 1 pound of methoxychlor or l/k pound 

 of lindane per acre. Allow one week between application of methoxychlor and har- 

 vest as hay or pasture, and 28 days with lindane. 



Armyworms are just starting to hatch in grass fields and roadsides in 

 the southern third of Illinois. Only a few have been observed in wheat fields 

 thus far. At this early date there is no way to determine how severe the infes- 

 tation wil.1 be or how general the egg laying has been. Moths are still migrating 

 from the south and will continue to do so for a few more weeks. They will lay 

 their eggs in the most vigorously growing grain. Armyworms will be most abundant 

 in lodged areas in grain fields within the next three weeks. 



Corn borer pupation has started as far north as Champaign, where k per- 

 cent of the overwintering borers have now changed to the pupal stage. A band 

 across north -central Illinois had the highest overwintering population of borers. 



Spring cankerworms are measuring or inch worms that feed on elm leaves 

 in the early spring. For control, apply a spray of h- pounds of lead arsenate, 2 

 pounds of 50 percent wettable DDT, or 2 quarts of 25 percent emulsifiable DDT per 

 100 gallons of water. 



Elm leaf beetles, small, dirty, yellow to black, spiny larvae, skeletonize 

 elm leaves. They are particularly severe on Chinese elms. To control them, use the 

 same insecticides as for spring cankerworm. 



Caution ; Before applying insecticides, read the labels carefully and 

 follow all precautions. This not only will insure personal safety, but will also 

 eliminate insecticide residue hazards. 



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This weekly report was prepared by H. B. Petty, Illinois Agricultural 

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

 Agricultural Research Service, Plant Pest Control Branch, from information gathered 

 by entomologists and cooperators who send in weekly reports from their own locali- 

 ties. 



