FOR IMMEDIATE RELEASE August 7, I96U 



INSECT SURVEY BULLETIN NO. 17 



This is the seventeenth 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 meas- 

 ures. These reports indicate only general trends. Each individual should check 

 his own fields to determine local conditions. 



European corn "borer pupation of first generation varies from 75 to 85 

 percent, and 30 to 50 percent of the moths have emerged. Eggs are "being deposited 

 in late corn. In most areas the situation appears to he less serious than last 

 year. However, in a few areas some sweet corn fields have higher egg mass counts 

 than they have had for the past several years. 



Corn earworm moth flight is just beginning in central and northern Illi- 

 nois, hut in southern and south-central areas egg-laying has begun. At present there 

 is an abundance of fresh and recently pollinated silks suitable for egg-laying. 

 Consequently the eggs are not being concentrated in a few fields but are being 

 scattered over many fields. Both moth flight and egg- laying are expected to in- 

 crease during the next several weeks. 



Corn leaf aphids are still numerous, but lady beetles and flower fly 

 larvae, both of which eat aphids, are becoming more abundant. Some parasitism of 

 aphids has also occurred. 



S oybean fields have infestations of green cloverworms, bean leaf beetles, 

 webworms and grasshoppers. All four are present in some fields. 



Green cloverworms have white pin stripes running lengthwise of their 

 bodies. In addition, the worms are very active and flip about as though on a 

 steel spring. As a rule this pest feeds only on leaves and rarely on pods or 

 blossoms. There should be at least six worms per linear foot of row to warrant 

 use of an insecticide for control. This is a minimum figure. 



To control, apply 1 l/2 pounds of toxaphene per acre, but do not use 

 foliage as feed for dairy animals or livestock being fattened for slaughter. There 

 is no time l i m i tation on combining of beans. Do not apply toxaphene adjacent to 

 fish-bearing waters or fields of dairy hay or pasture. 



Bean leaf beetles feed on leaves, pods and blossoms of beans. These 

 beetles are yellow, green or red .with up tq^|dur black spots on their back. At 

 the slightest disturbance they dV6p to t-hW'ground and "play possum. " Control is 

 not recommended unless defoliation ..£■£•> "severe or pods and blossoms are being eaten. 

 Then an application of toxaphene^will control them. 



Grasshoppers are now in the margins of soybean fields. As they grow, 

 their feeding will become noticeable. Also there are some still in fence rows, 

 ditch banks and similar areas, and with continued dry weather they may migrate to 

 beans. Grasshoppers also eat leaves, pods and blossoms. They are easily con- 

 trolled with toxaphene. 



