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COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT WEED & PLANT DISEASE SURVEY BULLETIN 



ATE/COUNTY/LOCAL GROUPS/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 





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FOR IMMEDIATE RELEASE 



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No. 13, June 26, 1970 



T/zis ser-tes o/ weekly bulletins provides a general look at the insect, weed,and plant 

 disease situation (fruit and commercial vegetables excepted) , along with suggested, 

 abbreviated control measures . Each individual should check his own fields to deter- 

 mine local conditions. 



INSECTS 



GENERAL 



Grasshoppers increased noticeably last year, and deposited eggs that overwintered. 

 The big, green differential grasshoppers deposited eggs in fencerows, grass sods, 

 ditchbanks, and roadsides. The smaller, red-legged grasshopper layed eggs in al- 

 falfa, clover, and other hay fields. These eggs are now hatching. 



Hard, beating rains will kill newly hatched grasshoppers, but will not kill them 

 after they are a few days old. Although some of the overwintering eggs may have 

 hatched during the recent rains and some tiny grasshoppers may have been killed, 

 the hatch continues. The grasshoppers hatched more recently may survive. 



You may find these tiny grasshoppers all over where soybeans or corn was planted 

 on hay-crop ground. Or, you may find them in this year's hay crop as the eggs were 

 layed in it last fall. Of course, the tiny differential grasshoppers can still be 

 found in fencerows and ditchbanks. If these tiny grasshoppers are very numerous, 

 as they are now in many areas, it will be easier to control them now while they are 

 small than it will be later. 



In fencerows, apply carbaryl (Sevin) , diazinon, malathion, naled (Dibrom) , or toxa- 

 phene. In hay fields, use the same materials except for toxaphene. Cut the hay and 

 drive the grasshoppers into an occasional uncut swath you have left. Then, spray it. 

 Carbaryl and malathion at 1 pound per acre require no waiting period after application; 

 naled requires 4 days; diazinon, 7 days. 



Provide protection around the edges as the grasshoppers migrate into soybeans. If the 

 migration is prolonged, you may have to spray the borders several times. Always read 

 the label for more -detailed restrictions. 



CORN 



European corn borer populations were not too severe in any of the fields examined 

 this week. In general, about 5 to 10 percent of the fields in any area are mature 

 enough for a high survival of the borers. Only 10 to 20 percent of such fields have 

 enough borers to warrant the use of an insecticide. In the area south of a line 

 through St. Louis, it is too late for optimum results by using an insecticide. A 



