-2- 



For corn or soybeans, apply 1 or 2 ounces of dieldrin or 1 1/2 lb. of 

 toxaphene. To protect seedings in small grain, apply 2 ounces of dieldrin or 

 1 1/2 lb. of toxaphene. Do not treat within one veek of harvest of the grain. 



Corn borer moth emergence is complete in central Illinois and is almost 

 complete in northern Illinois. Egg-laying, which had been progressing rapidly, has 

 practically stopped with the cool nights of this past week, but will proceed rapidly 

 as soon as night temperatures approach 60 degrees or above. 



A few fields in the area north of a line from Hoopeston to Bloomington to 

 Springfield to Quincy and south of Highway 6 may need treatment. However, these 

 are only the most advanced fields; the slightly later fields will need no protec- 

 tion. Although moths are still laying eggs, they will scatter them over many fields 

 rather than concentrate in a few. North of Highway 6, however, there is still a 

 possibility that egg-laying may be concentrated in some of the most advanced fields. 



If treatment is needed, it will probably be between June 20 and 27 In 

 central and north-central Illinois and between June 2h and June 30 in northern Illi- 

 nois. The timing will depend on how soon the remaining moths deposit their eggs. 



To determine need for treatment, examine 50 to 100 plants for signs of 

 borer feeding on the whorl leaves. If 75 percent or more of the plants show recent 

 whorl feeding,, check the tassel ratio. Measure from the base to the tip of the plant 

 with the leaves extended. Split the plant lengthwise, and measure from the base of 

 the plant to the tip of the developing tassel. Divide tassel height by plant height, 

 and multiply by 100. Take an average for five representative plants per field. 

 This is the tassel ratio. The corn will warrant treatment if the tassel ratio is 

 30 or above, but if possible do not treat until the ratio is at least 35 an d 

 preferably ^5* However, treatment after borers have drilled into the stalk proper 

 will not be effective. 



DDT is still the most common insecticide for corn borer. Apply 1 l/2 

 pounds per acre as a spray or 3/^ *o 1 pound per acre as granules. 



Other insecticides approved for use against corn borer are endrin and 

 toxaphene. Do not feed ensilage or stover of corn treated with DDT or toxaphene to 

 dairy cattle. Endrin may be used provided label restrictions are followed. 



Flies . House fly populations are increasing rapidly, and buildup of 

 maggots in manure has begun. Start good sanitation practices now and use residual 

 barn sprays of diazinon, ronnel, dimethoate, or Baytex (for beef barns only). 

 Supplement the overall spraying later with a spray bait of the same percent of 

 chemical, but use a base of 2 parts corn sirup to 1 part water. 



Horn flies and stable flies are becoming numerous on cattle. For dairy 

 cattle, apply 1 to 2 ounces daily of an oil base spray containing tabatrex, R-326, 

 or DDVP daily. For beef cattle, spray every 3 or k weeks with 0.5$ toxaphene water- 

 base spray at the rate of 1 to 2 quarts per animal. Allow 28 days between treatment 

 and slaughter when using toxaphene. 



Stored-grain insects . With wheat harvest just around the corner, stored- 

 grain insects hidden in empty bins are preparing for the big feast. Prevent damage 

 from these pests by sweeping up and cleaning out all old grain and other debris 



