FOR IMMEDIATE RELEASE July 29, I960 



BISECT SURVEY BULLETIN WO. 15 



This is the fifteenth in a series of weekly bulletins on the general in- 

 sect situation in Illinois (fruit insects excepted), prepared "by entomologists of 

 the Illinois Natural History Survey, University of Illinois College of Agriculture 

 and cooperating agencies. It is designed to forewarn people in Illinois of Impend- 

 ing changes in insect activity and to suggest abbreviated control measures. These 

 reports indicate only general trends. Each individual should check his own fields 

 to determine local conditions. 



Face flies : A face fly bait, DDVP, in a mixture of 75$ corn sirup and 

 25$ water, has been approved for daily application to the foreheads of cattle, in- 

 cluding dairy cattle. Label approval is based on use of 0.2$ DDVP. Each applica- 

 tion is to be made with a single six- inch stroke of a small paint brush. This 

 method is the result of research conducted by W. N. Bruce of the Illinois Natural 

 History Survey. Morning applications of the bait are recommended daily for a two- 

 week period, followed by other applications as needed. When the face flies feed on 

 the bait, the population is soon reduced to non-economic levels. Products conform- 

 ing to this label are or soon will be on the market. 



Corn leaf aphid : This pest is now present in tassels in the earliest 

 fields of corn. However, it usually does the most damage to late corn. Zero to 

 25 percent of the tassels in the early fields are moderately infested. In addition, 

 infestations in sorghum have been reported. Normally this pest will increase and 

 will probably migrate to the later fields. Sorghum may also be infested and damaged 

 more than corn. At what stage of development this aphid actually damages the corn 

 is not known, but the damage probably occurs during the pretassel to early tassel 

 stage. This is also true of sorghums. 



In severe infestations to corn, apply 1 pound of malathion per acre. Since 

 effect of aphid control on yield is not known, this treatment should be tried only 

 on a smr>ll scale, and accurate yield records should be taken. One-fourth pound of 

 parathion or phosdrin may be applied, but only by operators experienced in handling 

 and applying them. One day should elapse between applications of phosdrin and har- 

 vest, 7 days with malathion, and 15 days with parathion. These materials should be 

 applied to sorghums in the early boot stage. Allow three days to elapse between 

 application of phosdrin and harvest, 7 days with malathion, and 21 days with para- 

 thion. 



Armyworms and black cutworms : Large numbers of these moths have been 

 flying for the past few weeks. Grassy areas may be infested, but the high tempera- 

 tures of the past week should help to reduce the numbers of those worms. 



Fall armyworms : This pest may attack exceptionally late corn. A few egg 

 masses have already been observed. The worms feed deep in the whorl, and the feeding 

 becomes apparent as the leaves emerge. Usually the worms are found in several stalks 

 in small spots in the field. One and one-half pounds of toxaphene or l/k pound of 

 dieldrin as granules will give moderate control but should be applied only to fields 

 where worms are actually killing the heart of the corn plant. Do not apply within 

 kO days of harvest. Do not apply to ensilage corn to be fed to dairy cattle. Fol- 

 low restrictions on the label for use of treated foliage for non-dairy animals. 



European corn borer : Damage from second- generation borers may be more 

 severe this year than last. Start examining late fields of corn in south-central 

 and central- Illtopis^about August 1, and in northern Illinois about August 10. If 



r.'JS 1 - I860 



