after application. Do not harvest for 7 days after treatment with Imidan, meth- 

 oxychlor, diazinon, or mixtures of them. There is no waiting period for mala- 

 thion. Do not apply Imidan more than once per cutting. 



3. Using ground equipment . Apply a minimum of 20 gallons of finished spray per 

 acre, or 4 gallons by air. 



Alfalfa and clover hay crops may serve as a breeding area for beneficial insects, 

 such as lady beetles, aphid lions, and wasp parasites that attack many species of 

 aphids. When hay is cut, they move to other fields. Therefore, do not use insec- 

 ticides in alfalfa or clover fields unless it is necessary to save the crop and 

 unless you use all the hay you can produce. If there is a choice, harvest early. 



CORN INSECTS 



Soil insecticides . We have had several questions about the use of aldrin, hepta- 

 chlor, and chlordane as soil insecticides applied before or at corn-planting time. 



We have not recommended these materials for two years. Our main reason has been 

 the lack of favorable results in our field trials; also, their use, in general, 

 has not been profitable. A ruling by the U.S. Environmental Protection Agency 

 about a week ago still recognizes their use. A study panel stated that: "When 

 aldrin or dieldrin can be safely and economically replaced by persistent pesticides 

 they should be so replaced." "In the meantime use of these pesticides in applica- 

 tions directly to soil should be permitted." 



Again, the use of aldrin, chlordane, and heptachlor in Illinois corn soil is legal, 

 although no longer recommended by the University of Illinois College of Agriculture 

 since several insect species are no longer controlled by them. 



Our suggestion is to use a diazinon planter-box seed treatment in most instances. In 

 many cases, particularly on corn-soybean rotations, this has proved sufficient. Check 

 frequently to see that the addition of the extra dust does not decrease the seeding 

 rate. Where corn rootworms are involved, use one of the carbamates, such as BUX or 

 carbofuran, or an organic phosphate, such as Dyfonate, phorate, Dasanit, or prophos 

 (Mocap or Jolt). Dyfonate and phorate provide some control of small wireworms. 



Observe fields carefully in late May and early June for cutworms. At the first sign 

 of cutting, check the soil around plants carefully. If you find very many worms, 

 immediately apply a commercially prepared bait with carbaryl, a spray of carbaryl 

 with an attractant, or a spray of trichlorfon. 



SOYBEAN GROWERS: Residues of dieldrin (converted from aldrin) or heptachlor epoxide 

 (converted from heptachlor) can be found in soybeans grown in corn soil that has been 

 treated in past years. The amount is so small that only a legal problem of whether 

 or not it should be there is involved. Several years ago, it appeared that the ones 

 involved were soybeans grown on soil treated for the five consecutive years previ- 

 ously. Our 1971 studies showed that when soybeans were grown in soil treated the 

 previous year plus one other year of the previous five, a slight residue could be 

 found. In terms of this year's crop, if you used aldrin or heptachlor in a corn- 

 field in 1971 plus one other year back to 1966, beans grown in this soil in 1972 

 may have slight traces of dieldrin of no consequence other than the legal implica- 

 tion. Federal registrations or label specifications do not restrict the use of 

 aldrin or heptachlor in relation to soybeans being grown in subsequent years. 



