J- gj 



COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 



URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



^SECT WEED & PLANT DISEASE SURVEY BULLETIN 



ATE/COUNTY/LOCAL GROUPS/U.S. DEPARTMENT OF AGRICULTURE COOPERATING 



FOR IMMEDIATE RELEASE 



No. 14, July 7, 1972 



This series of weekly bulletins provides a general look at the insect, weed, and plant 

 disease situation (fruit and oorrmeroial vegetables excepted) , along with suggested, 

 abbreviated, control measures. Each individual should check his own fields to deter- 

 mine local conditions. £ l -'t j >, 



INSECTS AUr 



Armyworms were abundant in one no-till cornfield in northern Illinois 

 This particular field had been a rye field; the moths deposited their 

 weeks ago on the leaves of grasses or the rye. 



CORN INSECTS 



this past week, 

 eggs a few 



Armyworm moths have been extremely abundant for the past several weeks, and have been 

 flying northward. They may have been depositing eggs in grass fields or in grassy ar- 

 eas in com fields. Watch for tiny armyworms feeding in the grass. No control is 

 needed until they begin to eat the leaves on the upper part of the corn plant. If this 

 happens, apply a spray of 1-1/2 pounds of toxaphene per acre, if the field is in pol- 

 len and is being frequented by bees; if no bees are present, other chemicals may be 

 used as long as the instructions on the label are followed carefully. 



If you find dead or dying worms, you probably will not need to apply an insecticide. 

 A disease or fly and wasp parasites will often begin to kill the armyworms before they 

 can damage the corn. 



European corn borer moths have begun to emerge in extreme southern Illinois. Egg- laying 

 for another generation will begin any time, but will not reach a peak until July 20 to 

 30. During that time, the moths will prefer fields in the late-whorl to early silk 

 stage as a place to lay eggs. 



SOYBEAN INSECTS 



Leafhoppers are small, green wedge-shaped insects that run sidewise. They have ap- 

 peared in soybeans . The common Illinois varieties of soybeans are not affected by 

 leafhoppers, since all of those commonly grown are pubescent. This hair on the 

 leaves discourages or prevents the leafhoppers from feeding. We have had plots in 

 which smooth-leafed varieties were damaged by leafhoppers. 



Our recommendation is not to use insecticides except on the smooth- leafed varieties 

 as yields of the pubescent ones will not be affected enough to justify chemical con- 

 trol. However, if you believe that chemical control is warranted, one pound of mala- 

 thion per acre should suffice. 



FLY CONTROL AT COUNTY FAIRS 



Fair officials will need to be sure that manure, garbage, refuse, and soft-drink bot- 

 tles are removed from the grounds every day. This is a must. 



