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FOR IMMEDIATE RELEASE August 18, 1961 



INSECT SURVEY BULLETIN NO. 18 



This weekly 'bulletin will be the last one of the season unless insect con- 

 ditions warrant further ones. These bulletins have been prepared by entomologists 

 of the Illinois Natural History Survey, University of Illinois College of Agricul- 

 ture and cooperating agennies. They are designed to forewarn people in Illinois of 

 impending changes in insect activity and to suggest abbreviated control measures. 

 These reports indicate only general trends. Each individual should check his own 

 fields to determine local conditions. 



Grasshopper damage is more apparent in the northern half of the state than 

 in the southern half. Defoliation of corn, soybeans and clover in the northern half 

 of Illinois was noticeable this week even from the roadsides. The 'hoppers are now 

 migrating from hay crop fields, pastures and unused areas to soybeans and corn. Mi- 

 grations and damage will continue for two or three more weeks. 



To control 'hoppers in beans and corn, apply 1 1/2 pounds of toxaphene or 

 1/8 pound of dieldrin per acre. Allow kO days to elapse between application of 

 dieldrin and harvest of beans and corn as grain. Do not use treated plants as hay, 

 ensilage or stover for dairy animals or animals being finished for slaughter. 



If a band or border Is to be sprayed on the margin of a field and the 

 fencerow to control the migrating 'hoppers, Increase the dieldrin rate to l/k pound 

 per acre. If they are beginning to migrate from unused areas (reserve acres, road- 

 sides, ditchbanks, etc.), apply dieldrin, toxaphene, heptachlor or aldrin to them. 



If 'hoppers are still in uncut hay fields, apply 1 pound of malathion per 

 acre and allow one week to elapse between treatment and harvest or pasture. If this 

 is not desirable, cut the crop but leave one or two mower widths uncut. The grass- 

 hoppers will tend to concentrate in these areas, which can then be sprayed with any 

 of the insecticides. However, do not use this strip for hay or pasture - discard it. 



Webworms may attack fall- seeded alfalfa. In severe infestations the small 

 seedlings may be killed. If the worms are numerous and damaging plants, apply 1 1/2 

 pounds of DDT or toxaphene per acre before webbing becomes general. Do not use for 

 hay or pasture this fall. 



Spittlebugs and clover leaf weevils that attack hay crops in the spring 

 can be controlled now. Applications of DDT or lindane made between September 1 and 

 10 will kill adults before they lay their eggs. Do not use for hay or pasture this 

 fall. 



Face flies vary greatly in number from locality to locality and even from 

 herd to herd. They may become even more numerous during the next several weeks. 



Continue to use DDVP face fly baits daily or as needed on animals that can 

 be handled. For non-dairy animals that cannot be handled individually, backrubbers 

 with % toxaphene have been giving some relief from face fly attack when the animals 

 on pasture use them. Where the flies are not being controlled in this way, the only 

 solution may be to bring the cattle into dry lot and haul feed to them. See that 

 the animals have access to the darkest areas in the barn. Spray posts, board fences, 

 the sides of the barns and loafing sheds with diazinon or ronnel. Have a backrubber 



