near the damaged stalk. If the stand is being threatened or low spots in a field 

 are seriously damaged, apply 3 pounds of toxaphene per acre and direct the spray 

 at the base of the plants. Cultivate immediately to cover the spray deposit. 



On dairy farms, use 2 pounds of carbaryl (Sevin) per acre. This treat- 

 ment will help to control small worms but will not kill the large cutworms . 



Results with this insecticide will depend to some extent on soil moisture 

 and on rain immediately after spraying. Do not expect a spectacular kill of cut- 

 worms overnight. Evaluate control three or four days after treatment. 



If replanting is necessary, apply and disk in 2 pounds of aldrin or 

 heptachlor per acre for corn. Do not use aldrin or heptachlor soil treatments if 

 soybeans are to be planted. 



White grubs are damaging corn, soybeans and to a lesser extent small 

 grains and forages. These large (one inch or more) third-year cycle grubs will 

 stop feeding and pupate within another week or ten days. They are from about one 

 to six inches deep in the soil, and nothing can be done to protect the planting. 

 These grubs caused injury in these same fields during the 1965 growing season, 

 when they were in the second year of development. The fields had not been treated 

 in previous years with a soil insecticide. 



It is now best to wait out the feeding of the grubs. Warm, wet weather, 

 which enhances plant growth, would be helpful; continued dry weather would not. 

 Cultivating or hoeing would be of little benefit and might move the grubs that arc 

 between the rows closer to the plants. 



Common stalk borers have been tunneling in the whorl leaves of occasional 

 corn plants and stalks of oats. These striped borers are whitish-brown with a distinct 

 purple to black band around the middle of their bodies. The unfolding leaves of 

 corn have irregular holes from feeding, while the heads of oats turn white pre- 

 maturely. Damage occurs in plants along fence rows, ditchbanks and grass waterways 

 or where there was a weed problem the previous year. Injury is of little conse- 

 quence, and by the time the worms are found it is too late for chemicals to be ef- 

 fective. Keep weeds under control in August and September to help reduce the prob- 

 lem for next year. 



Upcoming Farm Insect Problems 



Corn borer emergence is about complete in the southern one-third of 

 Illinois, and egg laying is well under way. Egg laying will continue for another 

 week or ten days . 



Observe the occasional early-planted corn that is more advanced than 

 other corn in the area. 



To decide whether an insecticide can be profitably applied, measure the 

 tassel ratio of the field and count the percent of plants with recent whorl leaf 

 feeding. To determine the tassel ratio, measure the height of the plant with 

 leaves extended; split the stalk open and measure from the tip of the developing 

 tassel to the base of the plant. Divide the tassel height by the plant height, 

 and multiply by 100. This figure is the tassel ratio. If the tassel ratio is at 



