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FOR IMMEDIATE RELEASE July 1^, i960 



INSECT SURVEY BULLETIN NO. 13 



This is the thirteenth in a series of weekly bulletins on the general 

 insect situation in Illinois (fruit insects excepted), prepared by entomologists 

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

 culture and cooperating agencies. It is designed to forewarn people in Illinois 

 of impending changes in insect activity and to suggest abbreviated control meas- 

 ures. These reports indicate only general trends. Each individual should check 

 his own fields to determine local conditions. 



Grasshoppers : Moderate numbers of very small to one-third-grown grass- 

 hoppers are present in fence rows, ditch banks, roadsides and similar areas. The 

 beginning of grasshopper migrations into soybeans and corn was observed this week. 

 There may also be a few cases of damage to legume seedings in small grains. The 

 situation is not yet alarming, but in some instances it warrants attention. 



One- fourth pound of dieldrin or 1 1/2 pounds of toxaphene should now be 

 applied in locations where grasshoppers are concentrated. They can be controlled 

 more easily now than after they migrate to a larger area. If dairy pastures or 

 forage must be sprayed, use 1 pound of malathion, but do not pasture or harvest 

 for 7 days after application. Toxaphene may be used on forage crops to be fed to 

 non-dairy animals, provided they are removed from treated forage 6 weeks before 

 slaughter. 



Leafhoppers : Populations of these green, tiny, wedge-shaped insects 

 have built up in numbers in the southern half to one- third of Illinois. They suck 

 sap from alfalfa plants, causing them to be stunted and turn purplish-yellow. 

 Third-cutting alfalfa in northern Illinois could be damaged in quality if these 

 insect migrate northward, as they usually do. Jar plants over a white paper or 

 plate; if several insects are present, you may want to apply 1 pound of methoxychlor 

 per acre, but not within one week of harvest. 



Face flies : Populations of this fly, which cluster around the eyes and 

 noses of cattle, increased noticeably this week in the north half of Illinois. Fly 

 counts on herds of dairy and beef cattle on pasture ranged from 2 to 25 per head, 

 with an average of 8. Continued hot weather should bring a greater build-up of 

 these flies. Make counts on animals while they are on pasture, between the hours 

 of 10 a.m. and h p.m. Many of those examined had watering eyes and were obviously 

 being bothered by the flies. Herds were bunched up and were twitching their ears 

 and shaking and rubbing their heads instead of grazing. 



For control of these flies on dairy cattle, apply daily, to the animal's 

 head, repellent sprays containing tabatrex or R-326 in combination with pyrethrins. 

 Special face- fly- repellent sprays containing these materials are available and may 

 be used. About 60 to 70 percent reduction in the fly population can be expected 

 with these materials. 



For beef cattle, use a backrubber containing either 5 percent, DDT or toxa- 

 phene in oil. Success with backrubbers will depend on whether the .^OTsls can 

 smear a liberal supply of the chemical on their heads. Backrubbe^ constructed 

 with an outer layer of canvas, burlap or cloth, as opposed TOU^alj^P&d be best 

 for this purpose. Allow 30 days to elapse between this treatment and slaughter of 

 the animals. ^ .*^ xV 



