Special note : Mr. C. E. White of the Illinois Natural History Survey recovered 

 wasp and nematode (round worms) parasites from larvae and pupae (cocoons) of the 

 alfalfa weevil. These parasites were killing the weevil, but not in sufficient 

 numbers to provide control of the weevil as yet. This is encouraging; perhaps 

 in another few years, these natural enemies or others yet to establish may help 

 to alleviate problems somewhat. 



Small Grain Insects 



Armyworms are present in thick, rank stands of grains (wheat, barley, rye) and 

 grasses south of Highway 40. They are still small, and only occasional fields 

 have populations which could present problems. Along the north edge of this area, 

 the worms were just hatched (1/16- inch) in the grain fields and about a week old 

 in the grasses (1/4-inch to 1/2-inch). In the area south of Highway 13, the worms 

 are generally larger, and treatments may be needed by the end of the week (May 19) 

 in some fields. 



To find armyworms, examine lodged spots or the thick, rank areas first. Shake the 

 plants vigorously, and look on the ground for the worms. If small striped worms 

 are present, they will probably be armyworms. Do not use this count as a field 

 average. If you find no armyworms in these spots, no further examination is neces- 

 sary. If you find lots of them, make several additional counts over the entire 

 field. No control is needed unless the population averages six or more per linear 

 foot. Even then, do not apply insecticides until most of the worms are over one- 

 half inch long. 



Do not confuse the striped armyworms with the transparent yellow-to-green sawflies. 

 An armyworm has five pairs of abdominal prolegs; sawflies, six or more pairs"! 

 Sawflies do not damage wheat plants enough to require control. 



Apply 1 1/2 pounds per acre of toxaphene for armyworm control in small grains. 

 There are no restrictions on use of grain. Do not feed the straw to dairy animals 

 or livestock fattening for slaughter. Do not contaminate fish-bearing waters with 

 toxaphene. We have suggested that dairy farmers not use chlorinated hydrocarbons 

 on their farms. Toxaphene belongs to this group of chemicals. However, the offi- 

 cial label permits its use on dairy farms. If it is used on or adjacent to dairy 

 farms, avoid drift onto pastures and hay crops. Carbaryl (Sevin) , 1 pound per 

 acre, may be applied to fields adjacent to dairy pastures, but not after the heads 

 have begun to appear. Use carbaryl on grass pastures or hay fields if armyworms 

 are extremely abundant. But warn area beekeepers that you are applying carbaryl. 

 Trichlorfon (Dylox) , an organic-phosphate insecticide, may be used at 3/4 pound per 

 acre to within 21 days of harvest, but the straw should not be used for livestock 

 feed. 



The pup aria or "flax seed" stage of the Hessian fly is abundant in some wheat fields 

 in the southern sections. The wheat was stunted and the stands looked poor. The 

 dark-brown flax seeds can be found behind the lower- leaf sheaths. Nothing can be 

 done at this time for control. If Hessian flies are found to be numerous in a wheat 

 field, the field should be harvested as soon as the moisture content reaches a safe 

 level for storage. Otherwise, more of the straws weakened by prior feeding of the 

 maggot stage will break over and make combining difficult. 



Corn Insects 



Flea beetles continue to feed on small corn. Newly emerging corn should be watched 

 for the presence of small, shiny, black beetles that jump readily when disturbed 

 and leave white scratch marks on the leaves. For control, apply 5/4 pound of 



