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INSECT 



SURVEY 



BULLETIN 



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College of Agriculture 



University of Illinois 



and Natural History Survey, Urbana, Illinois 



State / County / Local Groups / U. S. Department of Agriculture Cooperating 



FOR IMMEDIATE RELEASE 





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INSECT SURVEY BULLETIN NO. 9 



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-June 9, 1967 



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This series of weekly bulletins provides a general look at the insect ./situation 

 (fruit insects excepted), along with suggested, abbreviated control measures. 

 Each individual should check his own field? to determine local conditions. 



Small Grain Insects 



Armyworms rate the insect of the iveek award. Infestations are generally heavy in 

 the thick stands of grains and grasses, particularly in the central and south- 

 central sections. The worms are about 2 weeks behind in their development, while 

 wheat development is normal or slightly ahead. Therefore, the likelihood of head 

 cutting and migrations as grains begin to ripen is much greater. Adjacent corn- 

 fields can be damaged severely by migrating armyworms. Head cutting and migrations 

 are occurring in the southern third of the state as grains ripen. In some fields 

 in the central area, the worms are still small (1/2-inch or less), and treatments 

 will not be needed until about June 12. 



Hot weather (90° F.) for several days could be detrimental to armyworms, as dis- 

 eases become widespread and kill them. Cool weather is favorable to their develop- 

 ment. Occasional off -colored armyworms suspected of having disease were found 

 this week. Also watch for little white capsules on the backs of armyworms. These 

 capsules are fly eggs, and the maggot that hatches penetrates the body of the worm, 

 killing it. 



Make a field count; if there are 6 or more armyworms per linear foot of drill row, 

 treatment is justified. Fields with a lower count (4 or 5 per linear foot) should 

 be watched closely; if head cutting or migration starts, treat immediately. 



Apply 11/2 pounds per acre (not 1/2 pound per acre as inadvertently quoted last 

 week) of toxaphene for armyworm control in small grains. At the first sign of 

 migration, treat a strip l-to-2 rods wide in the wheat and 8-to-10 rows wide in 

 corn, using 2 pounds of toxaphene per acre. There are no restrictions on the use 

 of the grain. Do not feed the straw or com forage to daiiy animals or livestock 

 fattening for slaughter. Do not contaminate fish-bearing waters with toxaphene. 



We have suggested that dairy farmers not use chlorinated hydrocarbons on their 

 farms. Toxaphene belongs to this group of chemicals. However, the official label 

 permits its use on dairy farms. If it is used on or adjacent to dairy farms, avoid 

 drift onto pastures and hay crops. 



