CORN INSECTS 



European corn borer pupation is 75 to 100 percent completed in the southern sections of 

 Illinois and moth -emergence is beginning. Egg-laying was observed in a field of early 

 planted sweet corn south of Route 13. In the central section, approximately 25 percent 

 of the borers have pupated. Pupation is just starting in the northern sections. 



All conditions considered, damage from first -generation corn borers could be serious in the 

 northern half to two-thirds of Illinois. Corn borer development is about a week behind, 

 compared with last year at this time. Early planted corn in the northern two-thirds of the 

 state may be sufficiently mature by mid- to late-June to attract moths and increase corn 

 borer survival . 



Flea beetles are damaging occasional fields of corn. Watch newly emerging corn for small, 

 shiny, black beetles that jump when disturbed and leave white scratch marks on the leaves. 

 If damage is severe and plants are being killed, apply 3/4 pound of carbaryl (Sevin) -- 

 preferred on dairy farms--or 1-1/2 pounds of toxaphene per acre as a band spray over the 

 row. Many fields being damaged are adjacent to grassy areas, fence rows, roadsides, and 

 grass waterways. Spray these to prevent additional flea beetles from moving into the corn. 

 Do not contaminate fish-bearing waters when using toxaphene. 



Black cutworms are conspicuous by their absence but can't be written off the books yet. 

 Watch the low, wet spots in the cornfields for damage. If damage appears, use a spray 

 directed at the base of the plants of carbaryl (Sevin) at 2 or 3 pounds, diazinon at 2 

 pounds, toxaphene at 3 pounds, or trichlorfon (Dylox) at 1 pound of actual chemical per 

 acre. It is best to use at least 20 gallons of water per acre and to cover the spray band 

 by throwing soil at the base of the plants with a cultivator. 



Common stalk borers caused considerable damage last year to border rows in many cornfields. 

 Whorl damage by this pest is often observed after it's too late to make a treatment. 



Damage most often occurs to cornfields adjacent to weedy fence rows, ditchbanks , road- 

 sides, or grass waterways. These are the places where the common stalk borer overwinters 

 in the egg stage. About mid- June, watch for damage to corn whorls by a whitish-brown, 

 striped worm with a purple band around the middle . Treatments are not effective unless 

 the infestation is spotted early. 



SMALL GRAIN 



True armyworms are being found in thick stands of wheat and barley in the southern half of 

 the state. So far, their number is low. Continue to observe wheat and barley fields dur- 

 ing the next two weeks. The presence of cool, wet weather is favorable for the development 

 of armyworms . 



Treatment is justified if there are six or more armyworms per foot of row as an average 

 over the field. Apply 1-1/2 pounds of actual toxaphene per acre for armyworm control in 

 small grains. There are no restrictions in use of the grain, but do not feed the straw 

 to dairy cattle or to livestock being fattened for slaughter. Do not contaminate fish- 

 bearing waters. Avoid drift onto pastures or hay fields. Trichlorfon (Dylox) at 3/4 

 pound of actual per acre may be used to within 21 days of harvest, but the straw should 

 not be used for livestock feed. Use carbaryl (Sevin) at 1 pound of actual chemical per 

 acre on grass pastures or hay fields. Warn area beekeepers when carbaryl is applied. 



