COLLEGE OF 

 AGRICULTURE 

 UNIVERSITY OF 

 ILLINOIS AT 

 URBANA-CHAMPAIGN 

 AND NATURAL 

 HISTORY SURVEY 

 URBANA, ILLINOIS 



NSECT WEED & PL A NT DISEASE SURVEY BULLETIN 



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



FOR IMMEDIATE RELEASE 



No. 10, June 9, 1972 



This series of weekly bulletins provides a general look at $fa§ insect, weedy and -plant 

 disease situation (fruit and commercial vegetabl&frvssti&eptedjy along with suggested, 

 abbreviated, control measures. Each individual should ^c^e\^.2his own fields to deter- 

 mine local conditions . 



INSECTS 





CORN INSECTS 



Black cutworm activity in the southern one-half of Illinois is starting to decline. 

 Occasional fields are infested with medium-sized larvae and are still being damaged. 

 However, cutworms in most fields are reaching maturity (about 2 inches when fully 

 grown) and are almost through feeding. 



Black cutworm damage in the northern one-half of Illinois is being reported. Fields 

 in this area should be watched closely during the week for signs of cutting, wilting, 

 or missing plants. 



This year, under dry conditions, cutworms have been cutting plants off below the soil 

 surface and growing point. Infestations have not necessarily been confined to the 

 low areas of fields as is usually the situation. 



If replanting is necessary, the cutworms will probably still be present when re- 

 planting is done. If most worms are 1-1/2 to 1-3/4 inches or larger, the corn can 

 be replanted without the use of an insecticide. The cutworms will have pupated by 

 the time the corn germinates. However, if most of the worms are small (3/4 to 1-1/4 

 inches) they will feed another 7 to 10 days and could seriously damage the new plant- 

 ing. In this case, apply the 5 -percent carbaryl (Sevin) , apple-pomace bait at 10 

 pounds per acre as a band over the row behind the press-wheel when planting. Do not 

 incorporate. A spray of 2 pounds per acre of actual carbaryl with molasses (Sevimol) 

 or with an attractant (Tractum) sprayed over the row a few days after planting could 

 be used in place of the carbaryl, apple -pomace bait. 



First-generation European corn borer damage is not expected to be a problem this year 

 in the southern one -half of Illinois. Corn borer development is generally ahead of 

 the corn, thus reducing borer survival and the threat of serious damage. 



In southern sections of Illinois, most corn is too small for borer survival. Egg 

 mass counts made in south-central sections revealed very low infestations. Further 

 south, egg hatch is virtually complete. Tiny borers present in fields where the 

 corn is less than 40-inches high will die. If egg-laying by moths extends over an- 

 other week in western areas along the Mississippi River, some of the fields of 50 -inch 

 or taller corn may be damaged. The survival of borers in these advanced fields will 



