FOR IMMEDIATE RELEASE April 23, 19^5 



f?6 6 -67 INSECT SURVEY BULLETIN NO . 1 



This is the first in a series of weekly bulletins on the general insect 

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

 University of Illinois College of Agriculture, Illinois Natural History Survey and 

 cooperating agencies. It is designed to forewarn people in Illinois of impending 

 changes in insect activity and to suggest abbreviated control measures. These re- 

 ports indicate only general trends. Each individual should check his own fields to 

 determine local conditions. 



European corn borer survival over the winter has been at or above normal 

 in all areas. Although the population is no greater than it was a year ago, with 

 the exception of the southern tip counties, the incidence of parasitism and disease 

 among the borers is very low. Therefore, borers are healthy; populations this spring 

 and summer could increase rapidly and damage could be severe. However, strong winds 

 or beating rains when overwintering moths are emerging could still eliminate the 

 problem. 



The potentially threatened area lies south and west of a line from Kankakee 

 to Rockford, north and west of a line from St. Louis to Springfield to Hoopeston, and 

 south of a line from Murphysboro to Ridgway. Farmers in these areas should plow 

 cornstalks cleanly, if possible. This will eliminate over 99 percent of the over- 

 wintering borers. Thorough disking, or stalk choppers or shredders should be used 

 on stalk fields not plowed. This will eliminate about 92 percent of the overwinter- 

 ing borers. Farmers should avoid early planting particularly on highly fertile soils 

 and use hybrids adapted to their area. Midseason plantings of corn will have less 

 injury from both first- and second-generation corn borer. 



Corn soil insects - A broadcast application of 1 1/2 pounds of aldrin or 

 heptachlor, disked in immediately except on dairy farms and fields with northern corn 

 rootworm resistance problems, is more dependable than row treatment. This is particu- 

 larly true in fields of first-year corn following a grass or legume sod, fields in 

 third-year or more of corn, corn grown in bottomland or having a history of cutworm 

 or other soil insect problems. However, for fields with average infestations of soil 

 insects and without a history of cutworm problems, row treatments with aldrin or 

 heptachlor have been highly satisfactory. No insecticide seed treatment is needed 

 when aldrin or heptachlor is used. 



Dairy farmers or farmers having a known or suspected field of resistant 

 northern corn rootworms should use diazinon, phorate parathion, or thiodemeton as gran- 

 ules in the row at planting time. In addition, when a phosphate insecticide is banded, 

 the seed corn itself should be treated with dieldrin or heptachlor to protect against 

 seed- infesting insects. 



Alfalfa weevil larvae are feeding on the terminal leaves and this feeding 

 is evident in many fields in the southern two tiers of counties. Alfalfa weevil lar- 

 vae have a partly black head, feed in the terminals, and are smaller than the clover 

 leaf weevil larvae which have tan heads and hide at the base of the plants during 

 the day. 



Overwintering adult alfalfa weevils are laying eggs, so worm feeding will 

 continue for another four to six weeks. At present fields are not seriously affected, 

 but the situation will bear watching. 



