Insecticide Suggestions To Control Insect Pests Of Field Crops In 1980 Extension Bulletin 388- Revised 1980 AGRICULTURAL EXTENSION SERVICE UNIVERSITY OF MINNESOTA Insecticide Suggestions To Control Insect Pests Of Field Crops In 1980 Legal Restrictions on Use of Pesticides In October 1977 certain provisions of the 1972 Federal Insecticide, Fungicide and Rodenticide Act became effective. In part, this, and the Minnesota Pesticide Act of 1976, require that those who use or supervise the use of certain pesticides with restricted uses must be certified. The labels ofthose pesticides with restricted uses will contain information regarding these restrictions. Be sure to read all labels thoroughly and use any pesticide for the crops and pests listed on the label only. The new law makes it illegal to use any pesticide in a way which is inconsistent with the label directions. Information about applicator certification may be obtained from your County Extension Director or the Minnesota Department of Agriculture. The U.S. Environmental Protection Agency (EPA) has listed the following as restricted-use insecticides: Aldicarb (Temik) Aluminum phosphide (Phostoxin) Methomyl (Lannate, Nudrin) Azinphosmethyl (Guthion) Methyl bromide Calcium cyanide Methyl parathion Demeton (Systox) Mevinphos (Phosdrin) Endrin Sodium cyanide Ethyl parathion Sulfotepp Tepp The following pesticides have been proposed for restricted use classification by EPA. After a period oftime for receiving comments EPA will issue a final order regarding the classification ofthese pesticides. Some ofthese products could have restricted use labeling during 1980. Pesticide Restricted uses and formulations aldicarb (Temik) agricultural uses of granules 10% and greater (other uses previously restricted) carbofuran (Furadan) granules 2% and greater (except on pine and cottonwood plantation and nursery plantings) carbon disulfide grain fumigation, burrow treatments for woodchuck, ground squirrel, prairie dog, and rats chloropicrin formulations greater than 2%, all formulations for rodent control cyclohexamide (Actidione) formulations greater than 4% The suggestions in this publication include only the use of insecticides for controlling insect pests of field crops. Other practices--such as crop rotation, time of planting, and appropriate selection of varieties--should also be considered.ln most situations, the use of insecticides is only part of a total effort to keep insect pests below the economic injury level. Where information is available, economic thresholds have been indicated in this publication. These are general guidelines that will vary, depending on stage of development of the crop, growing conditions, value of the crop, and other factors. The information given in this publication is for educational purposes only. Reference to commercial products or trade names is made with the understanding that no discrimination is intended and no endorsement by the Minnesota Agricultural Extension Service is implied. Authors of this publication are J. A. Lofgren, professor and extension entomologist; D. M. Noetzel, assistant professor and extension entomologist; P. K. Harein, professor Agriculture. Roland H. Abraham, Director of Agricultural Extension Service, University and extension entomologist; and L. K. Cutkomp. professor, Entomology, Fisheries, and of Minnesota, St. Paul, Minnesota 55108. The University of Minnesota, including the Wildlife. Agricultural Extension Service, is committed to the policy that all persons shall have Issued in furtherance of cooperative extension work in agriculture and home eco~ access to its programs, facilities, and employment without regard to race, creed, color, nomics, acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of sex, national origin, or handicap. 30' 2 Pesticide Restricted uses and formulations disulfoton (DiSyston) granules 10% and greater; granules 2% and greater except seed beds and transplant beds; granules 5% and greater in combination with ethoprop 10% and greater dicrotophos (Bidrin) liquid formulations 8% and greater ethoprop (Mocap) granules and fertilizer formulations 3% and greater EPN formulations greater than 4%; granules 2% and greater fenamiphos (Nemacur) granules 10% and greater fensulfothion (Dasanit) granules and fertilizer combinations 2% and greater fenthion (Baytex) all formulations for aquatic, ornamentals, and bird control uses; all liquids 70% and greater fonofos (Dyfonate) granules 5% and greater methamidophos (Monitor) liquids 40% and greater; dusts 2.5% and greater methidathion (Supracide) all formulations except on nursery stocks, safflower, and sunflower nicotine alkaloid formulations 14% and greater in greenhouses; all formulations on cranberries oxamyl (Vydate) liquids 24% and greater phorate (Thimet) granules 5% and greater temephos (Abate) aquatic uses; liquid formulations in orchards terbufos (Counter) granules 15% and greater zinc phosphide all dry formulations 60% and greater; all baits; all dry formulations 10% and greater for domestic uses In addition, EPA has announced a final order classifying the following pesticides for restricted use. Restricted use labeling may show up on some of these products from now on, but registrants have a waiting period for getting restricted use labeling in place so many may not be labeled until spring 1980. Pesticide Restricted uses and formulations carbofuran (Fu radan) all concentrates, suspensions, and wettable powders 40% and greater chlorfenvinphos (4072) all concentrates, solutions, or emulsions 21% and greater clonitralid (Bayluscide) wettable powders 70% and greater; all molluscide uses dioxathion (Delnav) concentrates, solutions, or emulsions 30% and greater; domestic uses of solutions 3% and greater disulfoton (DiSyston) concentrates 65% and greater; Emulsion Concentrates 21% and greater in combination with fensulfothion 43% and greater, E.C. 32% and greater in combination with 32% fensulfothion and greater; solutions 95% and greater for seed treatment; granules 10% and greater indoors (green houses) ethoprop (Mocap) Emulsion Concentrates 40% and greater fenamiphos (Nemacur) Emulsion Concentrates 35% and greater fensulfothion (Dasanit) Emulsion Concentrates and solutions 63% and greater; E.C. 43% and greater in combination with disulfoton 21% and greater; E. C. 32% and greater in combination with disulfoton 32% or greater fonofos (Dyfonate) Emulsion Concentrates 44% and greater monocrotophos (Azodrin) liquids 19% and greater 3 Pesticide Restricted uses and formulations phorate (Thimet) liquids 65% and greater; granules on rice phosacetin (Gophacide) 0.1% bait and greater phosphamidon (Dimecron) liquids 75% and greater; dusts 1.5% and greater Others may be restricted during the year. In addition, the Minnesota Department of Agriculture has classified lindane, some arsenicals, and some rodenticides as restricted. Carbaryl (Sevin), ULV Malathion, Methidathion (Supracide), Methyl parathion (Penncap M) and parathion are very toxic to bees. Crops in bloom should not be treated and applications should not be made near bee yards or when bees are present in the field to be treated. Some of the soil insecticides are toxic to fish. Use soil conservation practices to prevent soil erosion from treated fields. Avoid treating fields on steep slopes subject to erosion into surface waters. Aldicarb (Temik), demeton (Systox), disulfton (DiSyston), mevinphos (Phosdrin), methomyl, methyl parathion, parathion, phorate (Thimet), and phosphamidon (Dimecron) are highly toxic chemicals and should be used only by persons acquainted with the necessary precautions for their safe use. The granular formula­ tions are less hazardous to the operator than are the liquids. Avoid inhalation of dusts or vapors and contact with the skin. Follow directions on the labels for the use of protective clothing and other safety measures. Limitations, remarks Crop Insect Insecticide Dosage (Days before harvest) Alfalfa Alfalfa weevil azinphosmethyl Y2-% lb. 21 days, one application per cutting (Guthion) carbofuran (Furadan) ~-Y2lb. 7 days~ lb., 14 days Y2 lb. methyl parathion ~lb. 15 days phosmet (lmidan) 1 lb. 7 days, one application per cutting diazinon plus Y21b.+ 7 days-available as a ready-to-use methoxychlor 1 lb. mixture malathion plus %lb.+ 7 days-available as a ready-to-use methoxychlor %lb. mixture methidathion (Supracide) Y2 lb. 10 days Cut first crop early to avoid most losses. Treat when over 30% of plant tips show feeding. Treat stubble if there are more than 8larvae per sq. ft. or when regrowth has 50% of the terminals with feeding or if larvae are delaying regrowth. Do not treat alfalfa in bloom. Aphids and diazinon Y2 lb. 7 days leafhoppers dimethoate (Cygan, ~-Y2 lb. 10 days. One application per cutting. De-Fend, Rebelate, Dimex 267) malathion 1 lb. No time limitations parathion ~lb. 15days Control aphids when thick enough to cause wilting, usually during drought. Spotted alfalfa aphids may severely damage new seedings. Armyworm, carbaryl (Sevin) 1% lb. No time limitations, spray or bait cutworms malathion 1 lb. (or ULV) No time limitations trichlorfon (Dylox) 1 lb. spray or bait 7 days-spray methomyl (Lannate) ~-1 lb. 14 days-bait Treat when over 5 per sq. ft. 4 Limitations, remarks Crop Insect Insecticide Dosage (Days before harvest) Alfalfa Leafhoppers azinphosmethyl 1f4 to Y2 lb. 14 days carbaryl 1 lb. No time limitations diazinon 1/21b. 7 days methoxychlor 1 lb. 7 days malathion 1 lb. No time limitations methidathion Yz lb. 10 days (Supracide) phosmet