FOR IMMEDIATE RELEASE July 28, 196l 



INSECT SURVEY BULLETIN NO. 15 



This weekly bulletin on the general insect situation in Illinois (fruit 

 insects excepted) is prepared "by entomologists of the Illinois Natural History Sur- 

 vey, University of Illinois College of Agriculture 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. 



Although grasshoppers are still abundant in many areas throughout Illinois, 

 vegetation in fence rows and ditch banks may increase because of recent rain and 

 many of the grasshoppers may not migrate to cultivated crops. However, grasshoppers 

 are now large enough to see easily in fence rows, ditch banks, grass waterways, 

 clover, alfalfa, soybean and corn fields. If thry are abundant in fence rows, ditch 

 banks and similar areas, apply 1 1/2 pounds of toxaphene or 1/4 pound of dieldrin 

 per acre. For corn or soybeans, use 1 ounce of aldrin or dieldrin, or 1 l/2 pounds 

 of toxaphene. When using aldrin or dieldrin, allow kO days to elapse between treat- 

 ment and harvest. Do not feed toxaphene- treated forage to dairy animals or animals 

 being finished for slaughter. Use 1 pound of malathion per acre on forage crops or 

 pastures for dairy cattle. Allow one week to elapse between treatment with malathion 

 and harvest or pasture. 



Corn borers just started to pupate in northern Illinois this week. Pupa- 

 tion averaged 50 percent in western and southwestern Illinois, where egg laying for 

 second generation is expected to start late the week of August 7« 



First- generation borer populations in the area from St. Louis to Quincy 

 were lower this year than in i960 but about the same as in 1958 and 1959 . This is the 

 only area where population estimates have been made thus far. 



Green cloverworms , green worms with narrow lengthwise white stripes, are 

 appearing in soybean fields. These worms eat the leaves. To date only low numbers 

 have been seen in soybean fields. 



House flies will, with warm weather and moisture now present, increase 

 rapidly in number. Diazlnon and ronnel are recommended as residual sprays in barns, 

 around garbage pails and in other similar areas. Follow instructions on the label. 

 Scatter baits and liquid baits of DDVP, diazinon, dibrom, dipterex, malathion or 

 ronnel can be used to good advantage as a supplement to residual sprays. Even with 

 effective insecticides, however, good sanitation practices are the most important 

 step in house fly control. 



Face flies are still present in numbers and should be controlled before 

 the population builds up and becomes unmanageable. Use DDVP face fly baits on dairy 

 cattle and other cattle that can be handled. On non-dairy animals that can not be 

 handled, use 5 percent toxaphene in a backrubber. Do not apply toxaphene within 

 28 days of slaughter. 



Stable flies , which suck blood from cattle, breed in wet decaying straw, 

 hay or other similar material. Although they have been quite numerous for several 

 weeks, they may now increase rapidly. Use repellent and knockdown sprays Immediately 

 to protect dairy cattle during grazing. Pay particular attention to the legs and 

 undersides when spraying. 



WFUBWRYBFTHE 



JUI 28 ■ 



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