x n 7 



FOR IMMEDIATE RELEASE June ik. 1963 



INSECT SURVEY BULLETIN NO. 9 



This is the ninth 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 

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

 to determine local conditions. 



Corn borer emergence is complete or nearly so everywhere except in extreme 

 northern Illinois. Egg-laying is progressing rapidly in most areas. 



In west- southwestern Illinois many fields of field corn are satisfactory 

 for egg-laying. With the large acreage of tall corn, eggs will be scattered over 

 many fields and not concentrated in a few. In general, survival from eggs deposited 

 this week will be high, but egg-laying should be declining rapidly. 



In central and eastern Illinois, moths are concentrating in the more mature 

 field corn, but even in these fields egg counts are low and no fields were observed 

 this week that would require control measures. More eggs may be deposited this week, 

 however, and this could change the picture in some fields. 



In western Illinois, in the area bounded by a line from Rock Island to 

 Peoria to Quincy, egg counts are high but field corn development is such that most 

 of the borers that have already hatched will not survive. Moths are still deposit- 

 ing eggs and may continue to do so for the next week to ten days. The rate of egg- 

 laying will be decreasing, however. During this time survival of newly hatched 

 borers will be increasing as the corn develops. Observe the most advanced fields 

 of corn in this area for at least the next ten days. Follow tassel ratio and treat- 

 ment instructions as published in the bulletin last week. 



In northern Illinois, egg-laying has begun, but no predictions can be made 

 at this time. 



Armyworm infestations have occurred in several areas; no infestations have 

 been extremely severe, but many have required control measures to prevent economic 

 losses to wheat and corn. All sizes of armyworms have been present in the infested 

 fields. If there are six or more worms per linear foot of drill row in grain, apply 

 l/k pound of dieldrin or 1 l/2 pounds of toxaphene per acre. Do not harvest the 

 grain for at least one week after treatment. Do not use the straw until 30 days 

 after application. 



Chinch bug infestations may occur in dry areas in eastern Illinois, al- 

 though none have yet been observed. Examine thin areas or dying spots in small 

 grain fields for infestations. If migrations begin from small grain to corn, apply 

 1/2 pound of dieldrin as a border spray 1 or 2 rods into the grain field and into 

 the cornfields as far as the bugs are severe. Do not harvest small grain for one 

 week after treatment or use the straw until 30 days after treatment. 



Some numphs and adults have been observed in cornfields. If grasses were 

 plowed down late this spring, the nymphs on the corn will survive; but if some other 

 crop was plowed down, they will not survive. 



r«w 111963 



