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-T~~ <y Cooperative Extension Service, University of 



' Illinois College of Agriculture in Cooperation with 

 the Illinois Natural History Survey and U.S.D.A. 



FOR IMMEDIATE RELEASE July 2, 1965 



INSECT SURVEY BULLETIN NO. 11 



This is the eleventh in a series of weekly bulletins on the general in- 

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

 the University of Illinois College of Agriculture, Illinois Natural History Sur- 

 vey and cooperating agencies. It is 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. 



Chinch bug populations have been high in thin stands of wheat in an area 

 bounded by a line from Joliet to Peoria to Champaign to the Indiana border. Great- 

 est numbers are present in areas that had the least rain in the past month. As 

 grain dried during the past 10 days, the bugs began to migrate in search of green 

 food. They have killed grass weeds as well as wheat and corn in the path of their 

 migration, which reportedly has extended as far as ko rows into corn. In addi- 

 tion, corn planted on grass or grain sods is also infested with chinch bugs. 



To control chinch bugs as they migrate from small grain to corn, apply 

 1/2 pound of dieldrin per acre to a strip two rods wide into the grain and as far 

 into the corn as chinch bugs are clustered heavily. Do not apply dieldrin within 

 one week of grain harvest , and do not feed the straw to dairy cattle or livestock 

 being fattened for slaughter. 



Many persons have questioned the effectiveness of dieldrin as a barrier 

 treatment. First, it is necessary to spray the two-rod strip into the small grain 

 to expose bugs before they reach the corn. Second, dieldrin will not give fast 

 control. As chinch bugs die, they are rapidly replaced by new migrants. Dieldrin 

 is killing the bugs and will continue to do so for four or five days after applica- 

 tion. If migration continues, it may be necessary to reapply dieldrin. 



Where wheat was plowed under and planted to corn, concentrate the spray 

 at the base of the plants in an attempt to kill the bugs feeding on the plant be- 

 low soil level. Use 1/k pound of dieldrin per acre. 



Dairy farmers should not use dieldrin but might try one pound of carbaryl 

 per acre on the corn. Direct the spray to the base of the plants. Repeated treat- 

 ments may be needed during migration, as carbaryl is not so effective as dieldrin. 



European corn borer becomes less important as a potential problem with 

 each successive week. Although corn borer larvae can be found in many fields 

 throughout Illinois, numbers in general are low. Corn borer development was slightly 

 earlier this year than in previous years, and corn development was slightly later. 

 This meant poorer survival of corn borer larvae. In addition, moths scattered 

 their egg laying over many fields. Wind and rain at the peak of moth emergence 

 killed many of the moths before they laid their eggs . 



Pupation is progressing rapidly in southern Illinois, and moths for a 

 second generation should emerge within the next two weeks. A few eggs will most 

 likely be scattered in many fields. A third generation of borers will probably 



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