of the plant. Aerial applications should be granules, not sprays or dusts. Allow 

 10 days between treatment and ensiling of corn when applying diazinon; carbaryl 

 has no waiting period. Commercial applicators may prefer to use EPN or parathion; 

 they also provide good control of the corn borer. Parathion has a 12-day waiting 

 period between treatment and harvest; EPN, a 14-day waiting period. 



Black cutworm populations are declining as the worms pupate. Damage from this 

 generation is practically over, with the possible exception of the northern sec- 

 tions . 



Corn rootworms can be found feeding on corn roots in occasional cornfields. The 

 worms are less than half grown. It is too soon to predict overall abundance and 

 damage . 



Common stalk borers are feeding in the whorls of some corn plants and the stalks 

 of oats. These whitish-brown striped worms with a purple band around their mid- 

 dle cause irregular holes in unfolding corn leaves; in oats, the heads turn white 

 prematurely. Damage is most common along the edges of fields- -especially adjacent 

 to fence rows, ditch banks, roadsides, grass waterways, etc. Yellow striped army - 

 worms (velvety black with yellow stripes) are also present in the whorls of occa- 

 sional corn plants. Injury is of little consequence and by the time the stalk 

 borers or armyworms are found, it is too late for an insecticide to be effective. 



Small Grain Insects 



Armyworm populations have decreased rapidly and control measures need only be ap- 

 plied in a few special instances. It is now too late for maximum benefits from 

 control programs. Armyworm moths are large buff -colored insects; they usually 

 have a tiny white dot on the top of each front wing. In a week or two, they will 

 emerge in large numbers and fly northward, unless unseasonably cool or extremely 

 wet weather keeps them from flying. In the northern sections, late-maturing oats, 

 grassy cornfields, and grass pastures should be watched from early-to-mid July 

 for the presence of armyworms. 



Soybean Insects 



Clover root curculio and clover leaf weevil are damaging small soybeans planted 

 after clovers. Damage has also been observed in marginal rows of soybeans next to 

 a clover field that has been recently plowed or cut. The weevils are gray- or 

 brown- snout beetles that play dead when disturbed. They eat notches in the leaves 

 and gouge holes in the stem near ground level . The larvae of the clover root 

 curculio are grayish-white legless worms that feed on the roots, pitting and scar- 

 ring the surface and occasionally burrowing into the root. No control is avail- 

 able for the larvae. If needed for adults, band spray 1 pound of carbaryl or 1 1/2 

 pounds of toxaphene per acre. Carbaryl may result in a mite build-up in occasional 

 fields. Other insecticides may also be effective. 



Yellow and black grass thrips (about 1/16-inch long) are abundant in the whorl 

 leaves of corn and on soybean leaves. A few fields have been reported as being 

 damaged by these insects. The thrips rasp the surface of the leaves, making sil- 

 very patches. Plants will usually outgrow the damage and rain helps. If plants 

 are being seriously injured, use carbaryl (Sevin) at 1 pound per acre in corn or 

 malathion at 1 pound per acre in soybeans. Carbaryl may result in a mite build- 

 up if used on soybeans. 



