Digitized by the Internet Archive in 2011 with funding from University of Illinois Urbana-Champaign http://www.archive.org/details/insectpestmanage91981univ UNIVERSITY OF ILLINOIS ;. :y AT URSANA-CH AGRICULTLrt& CIRCULATING COPY ^ AGRICULTURE LIBRARY 1981 Insect Pest Management Guide FIELD and FORAGE CROPS You must be certified as a pesticide applicator to use restricted-use pesticides. See your county Extension adviser in agriculture for information. FEDERAL AND STATE LAWS The U.S. Environmental Protection Agency is classifying pesticides for "general" or "restricted" use. Anyone ap- plying a restricted-use pesticide must be certified. Only a few pesticides have been classified. Commercial applicators who apply restricted-use pesti- cides must be certified. Commercial applicators include not only persons applying a pesticide for hire but also govern- mental personnel, chemical company representatives, and others involved in demonstrational, regulatory, and public health pest control. Certification as a commercial applicator requires passing a written examination administered either by the Illinois Department of Agriculture or the Depart- ment of Public Health. Private applicators who use restricted-use pesticides "for the purpose of producing any agricultural commodity on property owned or rented by him or as exchange labor (no compensation) on the property of another" must also be certified, either by attending an educational training program or by passing an examination. Educational training programs for farmers (private applicators) and commercial pesticide applicators are con- ducted by the Cooperative Extension Service to prepare persons for certification. For additional information, con- sult your county Extension adviser in agriculture. The actual certification and the issuing of permits or licenses are handled by the Illinois Department of Agriculture or the Illinois Department of Public Health. Special Local Need Registrations Section 24(c) of the amendments to the Federal In- secticide, Fungicide, and Rodenticide Act of 1972 allows states the right to register pesticides for use within the state to meet special local needs (SLN). The authority for state registration of pesticides is the Illinois Depart- ment of Agriculture. A special label, which lists the new Asterisks (*) are used throughout this circular to in- dicate insecticides classified for "restricted" use by the U.S. Environmental Protection Agency. Consider all grain fumigants as restricted-use insec- ticides. 24(c) uses, is printed by the formulator. A copy of this label must be in the possession of the operator during application of the pesticides. In the following pages, all SLN, or 24(c), registra- tions are indicated by this sign: f. Insecticides and Classifications At the time this publication was in preparation, only a few of the insecticides listed below had been classified for either "restricted" or "general" use by the EPA. Addi- tional insecticides are expected to be classified before the Table 1. Insecticide Classifications Common natne Trade name Classification acephate Orthene unclassified azinphos-methyl *Guthion restricted" Bacillus thuringiensis Dipel, Thuricide, unclassified Bactur carbaryl Sevin, Savit unclassified carbofuran *Furadan restricted" carbophenothion Trithion unclassified chlorpyrifos Lorsban unclassified diazinon Diazinon unclassified dimethoate Cygon, De-Fend unclassified disulfoton *Di-Syston restricted" endosulfan Thiodan, Tiovel unclassified ethion Ethion unclassified ethoprop *Mocap restricted" fonofos *Dyfonate restricted" isofenphos *Amaze restricted'' malathion Cythion, malathion unclassified methidathion *Supracide restricted"" methomyl *Lannate, *Nudrin restricted"" methoxychlor methoxychlor unclassified methyl parathion *MethyI parathion restricted'' methyl parathion *Penncap-M restricted** (microencapsulated) oxydemeton-methyl . . . Metasystox-R unclassified phorate *Thimet restricted' phosmet Imidan unclassified terbufos Counter unclassified toxaphene Toxaphene unclassified trichlorfon Dylox, Proxol unclassified " Liquid formulations are restricted. '' All formulations are restricted. ' All formulations except water-soluble packages, 25% wettable powder, and granulars are restricted. UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN COLLEGE OF AGRICULTURE COOPERATIVE EXTENSION SERVICE In cooperation with ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 899 (revised annually) November, 1980 1981 planting season. Your county Extension adviser will have additional information on insecticide restrictions. The chemical names used in this circular may be un- familiar to you. These names are the common, coined chemical names and as such are not capitalized (for ex- ample, terbufos). Trade names are capitalized (for exam- ple, Counter). In the table of limitations (Table 14), the trade names are listed first, with the common name in parentheses following the trade name. In the tables of sug- gestions, tlie trade name is also listed first and the common name is in parentheses. For questions, refer to Table 1 or to Table 14. POLICY STATEMENT The Illinois Insect Pest Management Guide: Field and Forage Crops (Circular 899) is revised annually and is intended for use during the current calendar year only. Not all registered insecticides for crop pests are included in this circular. Insecticides that are effective and do not present an undue hazard to the user are suggested when- ever possible. Trade names have been used for simplicity, but their usage does not imply endorsement of one product over another, nor is discrimination intended against any product. This guide for insect control is based on research re- sults from the Illinois Natural History Survey, the Uni- versity of Illinois Agricultural Experiment Station, other experiment stations, and the U.S. Department of Agri- culture. Requested label clearances for a few uses of some in- secticides, carriers, and solvents are uncertain for 1981 because many requests have not yet been officially cleared. Be sure to check with your county Extension adviser in agriculture if you are in doubt about an insecticide you plan to use. We will make announcements of label changes through the news media to keep you up to date. REFERENCES This circular lists only suggested uses of insecticides for the control of many pests in Illinois field crops and is not designed to discuss other methods of control. Fact sheets discussing nonchemical control methods, descrip- tions of specific insects, and their life history and biology (designated by NHE numbers) can be obtained from the office of the county Extension adviser in agriculture or by writing to Entomology Extension, 172 Natural Resources Building, Champaign, IL 61820. PEST-MANAGEMENT SCOUTING PROGRAMS In recent years, "pest-scouting" programs have been initiated by several pest-management consulting firms to serve growers. Scouts monitor fields for outbreaks of pests and keep a close watch on potential problems. Identifying and controlling pest outbreaks through scouting programs could save a farmer thousands of dollars. The scout's ob- servations can also be used to determine the need for ap- plying a rootworm soil insecticide the following year. PESTICIDE SAFETY Certain precautionary steps should be taken when han- dling insecticides. Some of the insecticides suggested in this publication can be poisonous to the applicator. The farmer is expected to protect himself, his workers, and his family from needless exposure. When using insecticides, apply all the scientific knowl- edge available to make sure that there will be no illegal residue on the marketed crop. Such knowledge is con- densed on the label. READ THE LABEL CAREFULLY AND FOLLOW THE INSTRUCTIONS. The label should be recent and not from a container several years old. Do not exceed the maximum rates suggested. Observe the interval between application and harvest. Apply only to crops for which use has been approved. Keep records of pesticide use for each field. Record the product used, the trade name, the percentage content of the insecticide, the dilution, the rate of application per acre, and the date or dates of application. Always handle insecticides with respect. The persons most likely to suffer ill effects from insecticides are the applicator and his family. Accidents and careless, needless overexposure can be avoided. Following these rules will prevent most insecticide accidents: 1. Wear rubber gloves when handling insecticide con- centrates. 2. Do not smoke while handling or using insecticides. 3. Keep your face turned to one side when opening, pouring from, or emptying insecticide containers. 4. Leave unused insecticides in their original contain- ers with the labels on them. 5. Store insecticides out of the reach of children, irre- sponsible persons, or animals; store preferably in a locked building. Do not store near livestock feeds. Better yet, buy no more pesticide than you will use, thus eliminating a pesticide storage and disposal problem. 6. Triple rinse, bury, or burn all empty insecticide containers or take them to an appropriate sanitary landfill. 7. Do not put the water-supply hose directly into the spray tank or blow out clogged nozzles or spray lines with your mouth. 8. Wash with soap and water exposed parts of the body and clothes contaminated with insecticides. 9. Do not apply to fish-bearing or other waters. 10. Do not leave puddles of spray on impervious sur- faces or apply insecticides near dug wells or cisterns. 11. Do not apply insecticides, except in an emergency, to areas with abundant wildlife. 12. Do not spray or dust when weather favors drift. 13. To avoid bee kill, apply insecticides after bee activ- ity has been completed for the day; use the least toxic ma- terials. Warn beekeepers that you are applying insecticides. PREDICTING THE NEED FOR SOIL INSECTICIDES ON CORN The type of crop rotation greatly influences whether a soil insect problem will occur and what kind it will be. Some guidelines follow for predicting soil insect problems in corn and for determining tlie need to use a soil insecti- cide at planting time. Exceptions can be expected occasion- ally because soil insect problems are influenced by a variety of things unrelated to croj) rotation, such as the weather, soil type, planting date, hybrid, tillage, and nat- ural enemies. Knowledge about soil insect damage in a particular field during previous years is also helpful be- cause infestations tend to occur in the same fields and in the same area. Corn After Soybeans. The potential for soil insect problems in corn after soybeans is generally low, and the use of soil insecticides rarely pays. In most fields, a diaz- inon planter-box seed treatment will be adequate to protect against attack by seedcorn beetles and seedcorn maggots. Corn rootworms rarely cause damage to corn after soy- beans. An exception may occur when corn rootworm beetles are attracted to, and deposit their eggs in, soybean fields that are weedy or contain volunteer corn. When such fields are planted to corn the following year, economic damage may occur. Good weed control will reduce the attractiveness of soybean fields to rootworm beetles and permit soybean-corn rotations with noneconomic damage from corn rootworms. White grubs are an occasional problem in east-central Illinois in corn after soybeans. Corn After Corn. The potential for rootworm dam- age is moderate to severe in the northern two-thirds of Illinois. A rootworm insecticide may be needed in most fields of corn after corn. Wirewonns are occasionally a problem in the southern part of Illinois. Corn After Grass Sod. Wireworms and white grubs are potential problems. Apply a labeled soil insecticide at planting time. Corn After Legumes. Grape colaspis, grubs, wire- worms, and cutworms are potential problems in corn after clover and alfalfa. In northern Illinois, rootworms are occasionally a problem in corn following clover or alfalfa. Apply a soil insecticide at planting time. Corn After Small Grain. There is a slight potential for damage by wireworms, seedcorn beetles, and seedcorn maggots in corn after small grain. In most instances, a diazinon planter-box seed treatment will be adequate. If wireworms are present, use a soil insecticide at planting time. CORN ROOTWORM SITUATION Problem Area The number of western and northern corn rootworm beetles was considerably larger throughout most areas of Illinois during 1980 than in the previous two seasons. In h^X Potential for Rootworm Damage in Corn After Corn, 1981 MODERATE TO HIGH general, the larger the number of rootworm beetles, the greater the potential for economic damage by rootworms in corn following corn. Moderate to severe damage by western and northern corn rootworms may occur in the northern two-thirds of Illinois, north of a line from Collinsville in Madison County to Robinson in Crawford County (see map). The potential for damage in continuous corn south of this line is low to moderate, although an occasional field may sustain economic damage. These pre- dictions are based on a survey of rootworm beetle popula- tions made in 41 counties in August, 1980. Determining Potential Corn growers should base the need for using a root- worm soil insecticide in 1981 on the abundance of root- worm beetles in cornfields during late summer of 1980. If beetle numbers reached or exceeded one per plant at any time during late July, August, or September, 1980, plan to apply a rootworm soil insecticide if the field is to be replanted to corn in 1981. Fields of corn planted in late May or June. 1980. may have extensive rootworm damage if replanted to corn in 1981. During August and September, rootworm beetles are especially attracted to late planted or late maturing fields. Seeking fresh pollen and silks to feed on, the beetles lay millions of eggs in these fields. The heavy infestations may overwhelm even the most effective soil insecticide. Con- sequently, planting the fields to a crop other than corn in 1981 is suggested to reduce the overall rootworm pop- ulation. Rootworm Control Problems, 1980 Some soil insecticides used to control rootworm larvae in corn did not perform as well as expected in 1980. Fail- ures were reported with all commercially available prod- ucts, but failures with carbofuran (Furadan) and phorate (Thimet) were more numerous. Many factors interacting with one another affect the performance of a soil insecticide. Heavy rains immedi- ately following planting hasten the decomposition of soil insecticides and reduce control. Lack of rainfall may pre- vent the activation and movement of the insecticide from the soil surface to the area where rootworm larvae are feed- ing. Early planting is another problem, because soil insecti- cides applied in earh- to mid-April may have lost much of tlieir potency by the time rootwonn eggs hatch in late May and June. Hence, late hatching larv^ae have a high survival rate, and ultimately the number of beetles is large. These factors, coupled with insecticide rates that are too low, often result in poor or marginal rootworm control. Other causes of poor performance, particularly with Furadan, can be attributed to rapid breakdown of the in- secticide by soil microorganisms and increased tolerance of the rootworm larvae to the insecticide. Laboratory tests indicate a 30- to 50-fold increase in the tolerance of root- worm beetles to Furadan, compared with toxicity levels five years ago. SUGGESTIONS FOR ROOTWORM CONTROL, 1981 Crop Rotation Crop rotation is an extremely effective way to prevent damage by northern and western corn rootworm larvae. If feasible, do not grow com two years in succession in the same field. First-year corn following soybeans will gen- erally not require a soil insecticide for corn rootworm con- trol. Researchers at the Illinois Natural History Survey and University of Illinois have confirmed that a soybean- corn-soybean-com rotation is still effective in suppressing corn rootworms in Illinois. Although rootworm beetles can be found in "clean" or weed-free soybean fields, and may even lay a few eggs there, the number of eggs is not great enough to warrant the use of a soil insecticide on corn the following season. In a few instances, rootworm larval damage has occurred to corn planted after soybeans when the bean field had been heavily infested with volunteer corn or weeds during August. Adult northern and western corn rootworms were attracted to these weedy soybean fields to deposit eggs. As a result, root damage by larvae occurred the following season. Good weed control in soybeans will prevent root- worm damage in corn following soybeans. Soybean fields with 4,000 or more volunteer com plants per acre will usually warrant treatment for rootworm control the fol- lowing year if planted to com. Corn rootworm beetles deposit the vast majority of their eggs in cornfields. The larvae cannot survive on the roots of broadleaf crops (soybeans or alfalfa) or broad- leaf weeds. Consequently, when a crop other than corn, soybeans for example, is planted in a field with soil con- taining millions of rootworm eggs, the rootworm larvae die before becoming egg-laying beetles. Corn following alfalfa may benefit from a soil insecti- cide treatment, because rootworm beetles may be attracted into blooming alfalfa fields and lay eggs there during August and September. Soil Insecticides During the past five years, instances of erratic root- worm control with soil insecticides have increased. Several factors are involved, including early planting, too much rain, too little rain, and combinations of all three. In addi- Table 2. Soil Insecticides Suggested For Rootworm Control, Illinois, 1981 Ounces of product per Amount of product needed per acre Insecticide' Class 1,000 ft. of row 40" rows 38" rows 36" rows 30" rows At planting Amaze 20G organophosphate 6 5.01b. 5.3 lb. 5.6 lb. 6.7 lb. Amaze 6E organophosphate 1.6fl.oz. 11^ pints ly^ pints 11/^ pints 1^ pints Counter 15G organophosphate 8 6.7 lb. 7.0 lb. 7.4 lb. 8.71b. Dyfonate 20G organophosphate 6 5.01b. 5.31b. 5.61b. 6.7 lb. Dyfonate 4E organophosphate 2.4 fl. oz. 2 pints 21/^ pints 2Vi pints 254 pint? Dyfonate 4E organophosphate Broadcast 3 quarts 3 quarts 3 quarts 3 quarts Furadan lOG carbamate 12 10.01b. 10.5 lb. 11.11b. 13.3 lb. Furadan 4F carbamate 2.4 fl. oz. 2 pints 2\i pints 214 pints 25<4 pints Lorsban 15G organophosphate 8 6.7 lb. 7.0 lb. 7.4 lb. 8.71b. Mocap lOG organophosphate 12 10.01b. 10.51b. 11.11b. 13.31b. Mocap 6EC organophosphate 1.6fl.oz. 11^ pints \y^ pints I'i/l pints IYa pints Thimet 15G organophosphate 8 6.7 lb. 7.0 lb. 7.4 lb. 8.7 lb. At cultivation Amaze 20G organophosphate 6 5.01b. 5.3 lb. 5.61b. 6.7 lb. Amaze 6E organophosphate 1.6fl.oz. n^ pints 1>^ pints 11/2 pints 154 pints Counter 15G organophosphate 8 6.7 lb. 7.01b. 7.4 lb. 8.7 lb. Dyfonate 20G organophosphate 6 5.0 lb. 5.3 lb. 5.6 lb. 6.7 lb. Furadan lOG carbamate 12 10.0 lb. 10.5 lb. 11.11b. 13.3 lb. Mocap lOG organophosphate 12 10.0 lb. 10.5 lb. 11.11b. 13.3 lb. Thimet 15G organophosphate 8 6.7 lb. 7.01b. 7.4 lb. 8.7 lb. Consult text for more information. LIQUID FORMULATIONS ARE HIGHLY TOXIC. Table 3. Labeled Uses of Soil Insecticides on Corn Field Sweet Harvest Insecticide corn Popcorn corn silage interval Amaze yes yes yes yes 75 Counter yes yes yes yes * Dyfonate yes yes yes yes 45 Furadan yes no no yes * Lorsban yes no no yes * Mocap yes no yes yes * Thimet yes no yes yes 30 * No restriction when used according to label. tion, some research indicates that the erratic performance is clue to microbial degradation of the soil insecticide and to increasing tolerance of rootworm larvae to the in- secticide. Consequently, there is some uncertainty about how well a soil insecticide will control com rootworm larvae in a particular field or area. The suggestions for rootworm con- trol that follow are based on research conducted by ento- mologists in Illinois and other states. For more informa- tion refer to the section on rootworm control research. At Planting. Apply isofenphos (Amaze 20G, 6E), terbufos (Counter 15G), fonofos (Dyfonate 20G, 4EC), carbofuran (Furadan lOG, 4F), chlorpyrifos (Lorsban 15G), ethoprop (Mocap lOG, 6EC), or phorate (Thimet 15G) in a 7-inch band ahead of the planter press wheel at the suggested rate (see Table 2). IMPORTANT: Note the suggestions in the sections on using Furadan and on alternating insecticides. Soil insecticides will give 50- to 70-percent control of com rootworm larvae. This degree of control is adequate to prevent economic levels of larval damage In most fields. But in some heavily infested fields, enough larvae may survive to cause economic levels of root damage, and beetle populations may be large enough to interfere with polli- nation. Planting-time treatments applied in early April may provide only marginal control. Consider a cultivator appli- cation in late May or early June in such fields, rather than a treatment at planting time. Liquid formulations: Isofenphos (Amaze 6E), fon- ofos (Dyfonate 4E), or carbofuran (Furadan 4F) may be mixed with water and applied as a spray in a 7-inch band ahead of the press wheel. They may also be mixed with liquid fertilizer and used with a split-boot applicator at planting. Ethoprop (Mocap EC) is labeled only as a band spray mixed with water. Incompatibility or crop injury may be a problem in treatments using a liquid insecticide with a liquid fertilizer at planting. The insecticide must be compatible with the fertilizer. Conduct a test before planting to make certain that the two are physically compatible. Maintain agitation in the tank after mixing and during application to prevent separation. Use caution when handling liquid insecti- cide formulations. At Cultivation. Apply isofenphos (Amaze 20G, 6E), terbufos (Counter 15G), fonofos (Dyfonate 20G), etho- prop (Mocap lOG), carbofuran (Furadan lOG), or phorate (Thimet 15G) on both sides of the row at the base of the plants just ahead of the cultivator shovels. Cover the insecticides with soil. The best time to apply a basal treat- ment of a soil insecticide by cultivator is in late May or early June, near the beginning of Qgg hatch. Such treat- ments may be more effective than treatments at planting time in early April. Suggestions For Using Furadan. Rootworm con- trol with carbofuran (Furadan) has been erratic in recent years. Problems with Furadan in Illinois were first re- ported in 1975, and have continued to occur since then. Practically all instances of poor control have occurred in fields or areas where Furadan has been used intensively. Research indicates that poor control may be caused by a combination of microbial degradation of the insecticide and insect resistance. Laboratory research in 1980 indi- cates a 30- to 50-fold increase in the beetles' tolerance to Furadan, compared with toxicity levels five years ago. In addition, the breakdown or disappearance of Furadan applied at planting time is generally more rapid In fields where the product has been used previously. Preliminary research suggests that soil microbes may be responsible for the degradation. There Is some uncertainty about Furadan's place in current rootworm control programs. Furadan has per- formed effectively at some research locations and has been marginal or ineffective at others in recent years, including 1980. Consider the following suggestions for using Furadan In rootworm control: 1. If Furadan was used in 1980, switch to an organo- phosphate (Amaze, Counter, Dyfonate, Mocap, Lorsban, or Thimet) in 1981. 2. Do not use Furadan If rootworm control with Fura- dan was poor or marginal In recent years. In tests con- ducted in fields where Furadan failures were observed in 1975 and where organophosphate insecticides were used in the Intervening years, rootworm control with Furadan was still erratic in 1980. 3. Rootworm control with Furadan should be satis- factory in fields where it has never been used before. Suggestions For Alternating Insecticides. The suggestions that follow might help to improve control. 1. Consider alternating an organophosphate with a carbamate. Keep In mind, however, tliat growers generally have had no advance warning of poor control where prob- lems with Furadan (a carbamate) have occurred. 2. The advantages of switching from an organophos- phate to a carbamate are not apparent from the research, even where an organophosphate has been used for several consecutive years. But switching from one organophos- phate to another may have some merit. The continuous use of any one insecticide may create problems with insect resistance. To avoid this possibility, consider switching rootworm insecticides occasionally rather than using one product year after year. A word of caution, however, about rotating soil insecticides: in some instances, rotation of soil insecticides has not given good results. The performance of an insecticide that gives only fair control of rootworms will not be improved by rotation with other insecticides. Rootworm Control Research The relative effectiveness and consistency of rootworm control with various soil insecticides is investigated each year in approximately seven or eight replicated tests to keep abreast of any changes that might be taking place. The results of these tests have been published in the pro- ceedings contained in the 30th, 31st, 32nd, and 33rd "Illi- nois Custom Spray Operators Training School Hand- book," which is available at each county Extension office. The tests from 1977 to 1980 indicate that Amaze and Counter have given the most consistently effective control of corn rootworms. In general, rootworm control with Furadan and Thimet was erratic in the 1980 research tests, and neither product performed according to expectations. Although mediocre or poor control has been noted with organophosphate in- secticides in some fields each year, the cause does not seem to be related to insect resistance or microbial degradation. Control of Rootworm Beetles Use insecticides to control rootworm beetles where pollination damage may occur because of silk clipping. Re- search on spraying the beetles to prevent egg laying, there- by eliminating the need for a soil insecticide the next spring, has produced varying results. A single soil-insecti- cide treatment has usually been as effective as treating to control beetles in late July or early August and applying a soil treatment the following spring. Some growers may choose to experiment with the management concept of spraying rootworm beetles with carbaryl (Sevin 4-Oil) to prevent egg laying. In this case, the objective is to eliminate next year's larval infestation and the need for a soil insecticide. We encourage growers who make this decision to use the scouting services of a pest management consultant to monitor fields. A properly managed adult-suppression program will require weekly scouting during July and August. Even proper timing and application of an adult-suppression spray do not guar- antee success. Factors beyond the control of the operator, such as weather and beetle migration, may minimize the treatment's effectiveness. Scouting to Determine Rootworm Potential The abundance of rootworm beetles in a cornfield in July and August is an excellent indicator of future root- worm problems. Corn growers can determine the potential for rootworm damage in 1982 by counting western and northern corn rootworm beetles from mid- July through August, 1981, in this way: 1. Make 3 or more counts for western and northern corn rootworm beetles at 7- to 10-day intervals between mid-July and late August in fields to be replanted to com. 2. Examine 10 plants selected at random in each of 5 areas of the field. Count all of the western and northern com rootworm beetles on 50 plants each time. The counts take about 45 minutes in a 40-acre field. 3. As you approach a plant, move quietly to avoid dis- turbing the beetles. Count the beetles on the entire plant, including the ear tip, tassel, leaf surface, and behind the leaf axils. 4. Record the number of beetles you find per plant. If the average is more than one beetle per plant for any sampling date, plan to apply a rootworm soil insecticide in 1982. If average populations range from I/2 to 1 beetle per plant, the probability of economic damage the follow- ing year is low, and a soil insecticide is likely to be un- necessary. If populations do not exceed an average of Yz beetle per plant for any sampling date, a soil insecticide will not be needed the following season. Rootworm Life Cycle Western and northern com rootworm beetles deposit their eggs in the soil at the base of the corn plants or be- tween rows during August and September. The eggs over- winter in the soil and begin hatching in late May. Egg hatch usually takes place over a period of 3 to 5 weeks. Consequently, in July and August all stages of the corn rootworm — egg, larva, pupa, and adult — may be found. The rootworm larvae feed on the roots of corn plants dur- ing June, July, and August. When a larva is fully grown (1/2 inch), it builds a cavity in the soil and goes into the pupal or resting stage. After 5 to 10 days, the beetle emerges from the soil. The development from egg hatch to adult emergence takes 27 to 40 days. After the females emerge from the soil and mate, 14 days or more elapse be- fore they begin laying eggs. Rootworm beetles may deposit as many as 1,000 eggs; an average of 500 per female is probably common. Most egg laying in Illinois occurs after August 1. CORN CUTWORMS Black cutworm infestations were negligible in most areas of Illinois in 1980, compared with infestation levels of 1978 and 1979. Very few acres of com required re- planting or "rescue" insecticide treatments. Only a few growers who have problems every year reported black cut- worm damage in southern and western Illinois. Sandhill, dingy, and clayhacked cutworms caused some damage, according to several scattered reports. Although these cutworms were not widespread, some fields were heavily infested. All three species overwinter in Illinois as partly grown larvae, so the damage they caused occurred early in the season. Sandhill cutworms were a problem in sandy areas, where they cause damage almost every year. Dingy and claybacked cutworm infestations occurred more frequently in com planted after sod or forage legumes than in other crop rotations. Predicting cutworm outbreaks is still a guessing game. Sandhill cutworms, which are a problem in sandy soils, can be expected to cause damage each year. Dingy and claybacked cutworm infestations are influenced to a large extent by crop rotation and tillage practices. Black cut- worms, however, do not overwinter in Illinois, so it is impossible to forecast what the situation might be in 1981. A statewide program of monitoring black cutworm phero- mone traps provides information about the intensity of spring moth flights. But this program is still in the pre- liminary stage, and predicting infestations from moth catches is risky. Certain factors favor black cutworm outbreaks, how- ever. These factors include late planting, infestations of broadleaf weeds before planting, excess crop residue, and corn following soybeans. The most important factors may be late planting and preplant weed infestations. Fields that are planted late are more likely to develop a preplant weed infestation than fields that are planted early. These late planted fields with weeds are more attractive to cutworm moths as a site on which to deposit their eggs. Early spring tillage operations and early planting in 1980 were the key reasons for the apparent reduction in black cutworm out- breaks. Currently, three options are available for cutworm con- trol: preplant or planting-time applications of soil insec- ticides to prevent damage and rescue treatments after the infestation appears. All have limitations. Because of the uncertainty in predicting which fields will have light, moderate, or heavy infestations of cut- worms, it may be more feasible to use rescue treatments for cutworm outbreaks rather than to use a preplant or planting-time treatment unnecessarily. Based on the relatively low incidence of cutworm prob- lems over the past 25 years, a grower may find an eco- nomic advantage to the wait-and-see system, which in- volves field scouting, rather than a costly always-apply program in which the soil insecticide is routinely applied at or before planting for a problem that may not exist. Rescue (or emergency) treatments to control outbreaks of cutworms include sprays of chlorpyrifos (Lorsban), carbaryl (Sevin), or trichlorfon (Dylox), or carbaryl pel- letized bait. Broadcast the pelletized bait on the surface, but do not incorporate. Chlorpyrifos sprays should also be broadcast. Sprays of carbaryl may be banded over the row or broadcast, but the rates per acre need to be in- creased if the sprays are broadcast. Trichlorfon sprays should be banded. The keys to eflFective cutworm control with the rescue treatments are the amount of surface moisture and the movement of the worms. Control may be poor, regardless of the insecticide used, if the topsoil is dry and crusted and the worms are working below the soil surface. Cut- worm control under hot, dry soil conditions may be en- hanced by cultivating or running a rotary hoe over the field soon after spraying. This disruption may cause the worms to move around and come into contact with the insecticide. To determine the need for rescue treatments, scout the fields during plant emergence, particularly those fields con- sidered to be high-risk. Early detection of leaf-feeding or of cutting by cutworms is vital. When the corn plants are beginning to emerge, check the fields for leaf-feeding, cutting, wilting, or missing plants. Small cutworm larvae (less than I/2 inch) feed on the leaves and do not begin cutting plants until they are about half grown. A control measure is needed on corn in the 2-leaf stage if 3 percent or more of the plants are cut and if there are 2 or more cutworms per 100 plants. At the 4-leaf stage, control is justified if 3 percent or more of the plants are cut and if there are 4 or more worms per 100 plants. A single cutworm will cut fewer of the 4-leaf plants than those in the 2-leaf stage. Planting-time treatments of chlorpyrifos (Lorsban 15G), ethoprop (Mocap lOG), and fonofos (Dyfonate 20G) are registered for the control of cutworms in corn. The Mocap label states that Mocap will "control light to moderate infestations of cutworms"; Dyfonate is labeled for "suppression of black cutworms." Some growers may want to use one of these products in fields with a history of cutworm problems or in high-risk fields. Lorsban has provided the best cutworm control in research trials dur- ing the past few years. Research also indicates that plant- ing-time treatments are relatively effective in controlling light to moderate infestations, but control may be un- satisfactory for heavy infestations. Preplant broadcast treatments of chlorpyrifos (Lors- ban 4E) and fonofos (Dyfonate 4E) are also registered for corn cutworm control. Lorsban is labeled at rates of 2 to 4 quarts per acre; the higher rate is suggested. Dyfo- nate is labeled for "suppression of black cutworms" at 4 quarts per acre. Both insecticides should be incorporated into the top 2 to 4 inches of soil immediately after applica- tion. WIREWORMS Wireworm problems in com were more frequent in 1980, particularly in tlie southern half of Illinois, than for the previous 15 years. Wireworms may attack the seed or drill into the base of the stem below ground level, damag- ing or killing the growing point. Damage will show up as wilted, dead, or weakened plants and spotty stands. Wire- worm larvae are yellowish-brown and wirelike; several species are known to attack com. They live for two to five years in a field in the larval stage, feeding on the roots of grasses and crops. There is often a relationship between crops that were in the field two to four years before dam- age to the corn. Alost reports of damage to corn liave been in fields where corn follows soybeans or where there has been a corn-soybean-small-grain rotation. Presumably the adult (a click beetle) prefers to de- posit its eggs in small-grain stubble or in grassy fields of soybeans. Attempts to control wireworms with an insecti- cide rescue treatment after the damage appears are usually not very successful. Therefore, if an infestation is known to be present, insecticides must be applied at planting. Wireworms are usually most damaging in bottomlands or in poorly drained areas on upland soils. Low spots in the field often have the heaviest populations. The proportion of fields of com affected by wireworms in Illinois is small (less than 1 percent) and does not jus- tify the widespread use of a soil insecticide on first-year com after soybeans. A diazinon planter-box seed treat- ment at planting may help deter the wireworms from attacking the seed, but this treatment will not protect the seedling. Checking for Wireworms A technique using baits has been developed for evalu- ating wireworm potential before planting. The bait stations should be established 2 to 3 weeks before the anticipated planting date. Fields where small grain or grasses have been grown the preceding 2 or 3 years are the best candi- dates for bait stations. Since wireworm infestations are often localized within a field, it will be necessary to place the bait stations ran- domly throughout the field. One bait station per acre is desirable. As a minimum, place 2 bait stations at the highest elevation in a field, 2 on a slope, and 2 in the lowest area. Follow this procedure for baiting: 1. Use a mixture of 1 cup of untreated wheat and 1 cup of untreated shelled com at each station. 2. Bury the bait about 4 inches deep. It is also desir- able to cover the ground over each bait station with an 18-inch square of black plastic. The plastic collects solar heat and speeds germination of the com and wheat, which entices overwintering wireworms. 3. Mark each station with a flag or stake. 4. Dig up the bait stations in 10 to 14 days and count the number of wireworms. Need for Treatment If you find an average of one wireworm per bait sta- tion, use a labeled soil insecticide. In some instances, several wireworms may be found in one bait station and none in others. Wireworm infestations tend to concen- trate in some locations. It may be possible to limit treat- ment to areas of the field where the concentration is heaviest. WHITE GRUBS White grub problems in cornfields were more frequent in 1980 than during the previous couple of years. The species causing most of the damage in 1980 was Phyllo- phaga implicita. Two other species, P. futilis and P. rugosa, were less common, but they, too, occasionally damage corn and soybeans. All three species of economically important white grubs have 3-year life cycles. Peak years of damage usu- ally occur during the year following large flights of May beetles, the adult stage of white grubs. The beetles prefer to lay their eggs in ground covered with vegetation, such as weedy soybean fields and sod. The C-shaped white grub larvae chew on the roots and root hairs of corn seedlings. During peak years of damage, the grubs feed all season long. Damage to a cornfield is most apparent in the spring. Symptoms of white grub in- jury visible aboveground are irregular emergence, reduced stands, and stunted or wilted plants. The damage is usually spotty throughout the field. There are no established thresholds for white grub damage and no effective rescue treatments after the dam- age appears. However, if plants show symptoms of injury, dig around the root system of several corn plants. If white grubs are causing the problem and replanting is warranted, a soil insecticide should be applied. Terbufos (Counter 15G) is registered for the reduction of white grubs at the rate of 2 pounds of active ingredient per acre. In high-risk fields, such as corn following sod, a soil insecticide is justi- fied. Although not registered for white grub control, iso- fenfos (Amaze 20G), fonofos (Dyfonate 20G), ethoprop (Mocap lOG), or phorate (Thimet 15G) may give partial control. PLANTER-BOX SEED TREATMENTS Corn. A planter-box seed treatment with diazinon will protect germinating corn against attack by seedcorn beetles and maggots. Chlorpyrifos (Lorsban 50-SL) is labeled as a slurry treatment on seed before planting to protect germinating seed against injury by seedcorn maggots. Use a seed treatment in fields that do not receive a soil insecti- cide at planting time, or when carbofuran (Furadan) is applied at planting time. The diazinon planter-box seed treatment is not needed if terbufos (Counter), fonofos (Dyfonate), chlorpyrifos (Lorsban), ethoprop (Mocap), or phorate (Thimet) is applied at planting. NOTE: Ex- cess dust from the seed treater may interfere with the electronic monitor in air planters. Soybeans. Use a diazinon seed protectant to prevent damage to germinating soybeans from seedcorn maggots. Follow the label directions for application. The potential for damage is greatest during cool, wet springs when germination is slow. EUROPEAN CORN BORERS Overwintering larval populations in the fall of 1980 were larger than in the fall of 1979. Although this situa- tion was reflected by the statewide average number of borers per 100 corn stalks, regional averages were more significant. The differences in the numbers of overwinter- ing larvae among regions were large, but variability in larval counts from county to county and from field to field was even more dramatic. Numbers of larvae per 100 stalks ranged from as few as 21 in the east to as many as 502 in the southwest. Generally, the overwintering population in southern Illinois is much larger than in the northern half of the state. The potential for first-generation infestations in 1981 is moderate to high throughout most of the state, and very high in southern Illinois. The overwintering borer population, however, should be affected to some degree by the incidence of disease organisms. Spring weather in 1981 will also affect the population of first-generation borers. Com borer moths begin to emerge in late May in southern Illinois and mid- to late June in the central and northern regions. The females lay most of their eggs in the evening. They spend the daylight hours in fencerows and other protected areas. The eggs, which are laid in masses, are usually de- posited near the midrib on the underside of the lower corn leaves. Calm nights favor egg deposition by the moths. The absence of hard, beating rains during moth emergence also increases the potential for infestations. Corn that is planted early (the fields with the tallest corn) should be monitored closely for signs of whorl- feeding by corn borer larvae from mid-June to early July. The fields with the tallest corn are the most attractive for ^g? laying by first-brood moths. Control is warranted if 50 percent or more of the plants have fresh whorl-feeding, if live borers are present, and if plants are 24 or more inches tall (with the leaves extended). First-generation borers reduce yields by stalk-tunnel- ing, which weakens the plant and destroys the tissue used to transport food within the plant. Some hybrids have varying degrees of tolerance or resistance to leaf-feeding by first-generation borers. Con- sider this trait when selecting varieties for 1981. Com planted late is most attractive to moths laying eggs for the second generation. Fields should be monitored from mid-July to mid-August for egg masses or newly hatched larvae of the second brood. Control measures are warranted if there are 100 or more egg masses per 100 corn plants. For best results, treatments should be applied soon after egg hatch to kill the young larvae before they bore into the plant. Because egg-laying for the second generation extends over a 3- to 4-week period, timing of insecticide application should be precise. Occasionally two treatments may be necessary for satisfactory control. Yield losses caused by second-generation borers are a result of stalk breakage and ear drop (physical damage), as well as physiological damage. Corn-borer entrance holes also provide avenues for stalk rot organisms. CORN LEAF APHIDS Many fields of corn in east central Illinois had heavy infestations of corn leaf aphids in 1980. The effect of these large populations on yield is not known, but they un- doubtedly placed additional stress on plants that were al- ready suffering from lack of soil moisture. Corn leaf aphids are small, soft-bodied, greenish-blue plant lice about the size of a pinhead. They do not over- winter in Illinois, and it is impossible to predict what the situation will be in 1981. Winged corn leaf aphids, blown into Illinois on southwesterly winds during mid- to late June, become established within the whorl leaves of the corn plant. These aphids give birth to living young. In the absence of predators, parasites, diseases, and hard beating rains, aphid populations may increase very rapidly; that was the situation in 1980. Corn leaf aphids have sucking mouthparts and cause damage by sucking moisture from the corn plant. Soil moisture stress and heavy infestations on the upper leaves and tassel may result in barren plants or reduced ear size. The critical period for damage is during tassel emergence through pollination. If aphids are allowed to cover the tassel and upper two or three leaves, yield losses are likely to occur. Fields should be scouted for aphids beginning about one week before tassel emergence. Pull and unroll the whorl leaves of plants selected at random to check for aphids. Treatment is suggested if 50 percent of the plants have 100 or more corn leaf aphids per plant during tassel emergence and if plants are under drouth stress. Aphid populations usually decline after pollination is complete. However, treatment may be warranted following pollina- tion if aphid populations continue to cover the tassel and one or two of the upper leaves. REDUCED TILLAGE AND NO-TILL INSECT PESTS Concern about insect problems should not keep growers from adopting conservation tillage practices. The soil-in- sect complex in com, which is similar in many ways for conventional and reduced-tillage systems, can be readily controlled by applying soil insecticides at planting time. With a few exceptions, outbreaks of insects feeding on foliage can be controlled with properly timed treatments of insecticides. Close monitoring of fields to detect in- sect outbreaks is very important, regardless of the till- age system. Weather conditions and the type of crop rotations de- termine to a great extent whether a soil insect problem will occur and what kind it will be. In some instances, tillage may also influence the kind and abundance of an insect pest. Some tillage operations favor specific pests. Others tend to reduce pest problems. The general expectation is that insect infestations will be more pronounced where no- tillage is used in corn than where conventional or reduced- tillage systems are used. No-Till Pests Insect problems occur more frequently in no-till corn than in any other conservation tillage system and are often more serious. Crop residue left by the use of no-till prac- tices provides a stable environment for pest survival and development. Pest problems occurring under these condi- tions include European corn borer, cutworms, armyworm, common stalk borer, wireworms, seedcorn maggots, bill- bugs, slugs, and mice. Soil insecticides may be needed on no-till corn following corn (in rootworm area), grass sod, legumes, or following any crop in which grasses and broad- leaf weeds are prevalent. Soil Insect Control Select a soil insecticide that will control the anticipated soil insect pest. Consult Table 4 for suggestions. If a soil insecticide is not applied at planting, a diazinon planter- box seed protectant will give protection against seedcorn maggots and seedcorn beetles. Surface residues from no-till and reduced-tillage sys- tems may present some problems with the placement and incorporation of granular soil insecticides applied at plant- ing. To be most effective, the soil insecticide should be in- corporated into the upper Yz inch of soil, and not just broadcast on the surface. Granules remaining on the soil surface are degraded by sunlight, resulting in erratic or poor control. Furadan lOG is the only soil insecticide labeled specifically at planting for no-till conditions. NOTE: Before using Mocap, Dyfonate, or Thimet on no-till corn, be sure that soil moisture is low enough to ensure closing of the seed furrow to prevent the insecti- cide granules from contacting the seed. Crop injury may occur with these products. Aboveground Insect Pests Aboveground insects will be more of a problem in no- till corn than under reduced or conventional tillage. Corn planted in grass sod or fall-seeded rye is vulnerable to attack by armyworms. The moths lay eggs on the grasses during April or early May. After vegetation is killed by a herbicide, the larvae move to the young com seedlings and feed on them. Control is justified when 25 percent of the plants are being damaged. Rescue treatments are effective, but a spray volume of 15 to 20 gallons per acre will im- prove coverage and control. Instances of damage to corn by the common stalk borer have been greater in no-till com than with other tillage systems. Moths of this insect deposit their eggs on weeds in late August and September. When a herbicide is applied in the spring to no-till com in fields previously infested with host weeds, the newly hatched stalk borer larvae move from the dead vegetation and attack newly emerging corn plants. Control of common stalk borer with insecticides is generally poor because the worms do not have access to the chemical. Noninsect pests in no-till corn include slugs and mice. There are no effective control measures for slugs. Mouse damage may be a severe problem, particularly in corn fol- lowing sod. To reduce or prevent mouse damage to corn, use a hopper-box seed treatment of methiocarb (Mesurol 50% bird repellent) at the rate of 1 pound per 100 pounds of seed corn. This product has a state label. FORAGE INSECTS In 1981, we expect alfalfa weevils to cause moderate to severe damage to the first cutting of alfalfa in most areas of Illinois. Populations of overwintering weevils in south- ern Illinois are the largest they have been in several years. In the southern counties, where a lot of egg laying takes place in the fall, alfalfa- weevil larval damage occurs early in the spring. Damage to the first cutting in northern Illinois is more likely to occur if hay harvest is delayed. Otherwise, the injury to alfalfa in the nortliern counties will occur on the stubble and new growth of the second cutting. Numbers of alfalfa weevils are regulated to a large ex- tent by winter weather. During a cold, open winter the mortality rate is high in overwintering weevil populations; during mild winters the mortality rate is low. The large, damaging numbers that occurred in the spring of 1980 were primarily a result of last year's mild winter. A parasitic wasp and a fungal disease organism that attacks alfalfa weevil larvae sometimes regulate weevil numbers in the spring. The fungal disease, which was first found in Illinois in 1979, was not a significant factor in 1980, so weevil lan^ae were not held in check. The effect that natural enemies and diseases have on alfalfa weevil populations is still unknown. Altliough the wasp and the fungus will be present in alfalfa fields in 1981, we cannot yet predict their effect on weevil numbers. Alfalfa growers in southern and central Illinois should inspect their fields closely in April, May, and June. Early larval damage appears as pinholes in the growing terminals. As the larvae grow, they skeletonize the leaves, and dam- aged fields appear tattered. Growers in northern Illinois should look carefully for larval damage in late May and June. All growers should examine the stubble after the first cutting, because larval and adult feeding can slow or halt new growth. Follow the suggestions in Circular 1136, "Alfalfa Weevil Pest Management Program," to deter- mine the need and proper timing of a treatment. If this circular is unavailable, a rule of thumb is to treat when 25 percent of the tips are being skeletonized. This threshold 10 may be as high as 40 percent in northern Illinois, where damage occurs later in the season. Potato leafhoppers may cause moderate to severe dam- age to the second and third cuttings of alfalfa in all areas of Illinois in 1981. Damage first appears as a yellow, wedge- shaped area at the tip of the leaf and is more evident dur- ing dry weather. However, population levels are difficult to predict because the leafhoppers do not survive the winter in Illinois. They migrate from southern states into Illinois during May and June. Potato-leafhopper damage may begin on the new growth as soon as the first hay crop is removed. (Stunting and yellowing are signs of leafhopper injury.) A swarm of leafhoppers at the time of the first cutting indicates that there may be a problem in the new growth. If you use a sweep net to monitor fields, apply treatments when there are one or more leafhoppers per sweep. BEAN LEAF BEETLES Bean leaf beetles occurred in very large numbers throughout southern and central Illinois during August, 1980. The unusually large population was the result of several factors that enhanced the survival and development of the beetles. The 1979-80 winter was mild, so many of the overwintering beetles survived and emerged during the spring of 1980. The beetles, which were able to colonize successfully on early planted soybeans, laid large numbers of eggs. Finally, the hot weather throughout the summer accelerated beetle development. As a result, more beetles than usual were present in August. The beetles caused considerable leaf-feeding injury to double-cropped soybeans and late maturing soybean vari- eties. Insecticide treatments were recommended during the critical pod-set and pod-fill stages, when defoliation ex- ceeded 15 to 20 percent. The greatest concern, however, was caused by the beetles' pod-feeding damage, which left scars on many pods. These scars predisposed the pods to fungal infections. We are still uncertain how much pod- feeding affects yields. Bean leaf beetles overwinter as adults under debris in fencerows, wooded areas, and other protected sites. The overwintering population of beetles is large, so there is a potential for large numbers of beetles emerging in the spring of 1981. However, the survival of the overwintering beetles will depend on the winter weather. Another mild winter will increase the chances for a large population in the spring. In addition, if soybeans are planted early in 1981, the beetles will establish themselves early. The avail- ability of soybeans during the early part of the season is essential for the survival of bean leaf beetles. The survival of large numbers early in the season generally means an even larger population in August. On the other hand, a severe winter and later planted soybeans will reduce the number of bean leaf beetles in the spring. CHEMICAL INJURY TO SOYBEANS There have been instances of phytotoxicity to soybeans when organic phosphate soil insecticides were used. The problems have occurred where growers started planting soybeans without first emptying the insecticide boxes. Or- ganic phosphate soil insecticides applied in soybean fields treated with metribuzin (Sencor or Lexone) may result in injury to a soybean crop, according to information on the labels. CALIBRATION FOR SOIL INSECTICIDES Calibrate the applicators for granular soil insecticides before the planting season begins. In some instances, poor control is caused by applying rates that are too low. Proper calibration will help avoid this problem. Most soil insecti- cide bags have a list of suggested settings for the partic- ular model of applicator. The settings are based on plant- ing speed. The beginning settings are helpful, but be sure to check your actual application rate under your own oper- ating conditions. Follow these steps for calibrating the applicator: 1. Calibration of granular applicators for soil insecti- cides is usually based on determining how many ounces of product are needed per 1,000 feet of row. Consult the in- secticide label or Table 2 for labeled rates for rootworm control. These rates are expressed in ounces per 1,000 feet of row and pounds of product per acre. 2. Consult the label or manufacturer's recommendation for an approximate application setting. Adjust the setting on each hopper. 3. Select an area for a test run, preferably in the field, so that speed and traction conditions are constant. Measure off 1,000 feet. 4. Fill the hoppers and attach a plastic bag or con- tainer to each delivery tube to catch the granules from each hopper. 5. Drive the premeasured distance (1,000 feet) at the same speed to be used during the planting operation. 6. Weigh the material collected from each hopper. Use a scale tliat weighs in ounces (e.g., a postal scale or a diet scale). 7. Compare the quantity (ounces) per bag against those given in Table 2. To obtain one pound of active in- gredient per acre the following amounts of material should be collected: Formulation, percent 10 15 20 Oz. collected per 1,000 ft. 12 8 6 8. Recalibrate if the difference in quantity applied dur- ing the calibration process is more than 10 percent over or under the rate suggested on the label. 11 Table 4. Field Corn Insect Time of attack Insecticide* Pounds of active ingredient per acre Placement Timing of application Corn rootworm June-August larvae **Amaze (isofenphos) Counter (terbufos) **Dyfonate (fonofos) **Dyfonate (fonofos) **Furadan (carbofuran) Lorsban (chlorpyrifos) **Mocap (ethoprop) Thimet (phorate) 1" 1" 3 1" 1" 1" 1" 7-incli band 7-incii band 7-inch band Broadcast -PPI' 7-inch band 7-inch band 7-inch band 7-inch band (See text on soil insecticides at planting time.) Basal treatments during cultivation with Amaze, Furadan, Dyfonate, Thimet, Counter, or Mocap are effective in late May or early June. Seedcorn maggot At germination Counter (terbufos) diazinon 1" 11/2 oz. a.i. per bu. **Dyfonate (fonofos) P Furrow On seed 7-inch band At planting. Lorsban (chlorpyrifos) 1 oz. a.i. per 100 lb. of seed On seed Slurry formulation used to treat seed before planting. Seedcorn beetles At germination diazinon li/4 oz. a.i. per bu. **Dyfonate (fonofos) 1" Thimet (phorate) l*" On seed 7-inch band 7-inch band At planting. Wireworms May-June Counter (terbufos) Counter (terbufos) **■ Dyfonate (fonofos) **Dyfonate (fonofos) **Furadan (carbofuran) **Mocap (ethoprop) Thimet (phorate) 1" 1-2" 1" 4 2-3" 1" 1" Furrow 7-inch band 7-inch band Broadcast-PPP Furrow, band 7-inch band 7-inch band Thimet and Dyfonate applied in a 7-inch band are labeled for suppression of wire- worms. Cutworms May-June Lorsban granules (chlorpyrifos) Lorsban spray (chlorpyrifos) 1' 1-2 7-inch band Broadcast-PPP At planting. **Dyfonate (fonofos) 1" **Dyfonate (fonofos) 4 7-inch band Suppresses cutworms. Broadcast-PPP **Mocap (ethoprop) 7-inch band At planting. Controls light or moderate in- festations. Lorsban spray (chlorpyrifos) Sevin spray (carbaryl) Sevin bait (carbaryl) Dylox, Proxol spray (trichlorfon) Ml/2 2" 1-2 1" Broadcast Plant base Broadcast Plant base Apply as a post emergence rescue treat- ment when damage appears. White grubs May-October Counter (terbufos) 2" 7-inch band Counter is labeled for reduction of white grubs at planting. Garden symphylan May-July Counter (terbufos) **Dyfonate (fonofos) 1-2" 2 7-inch band Broadcast-PPP At planting. Billbug May-June toxaphene 2" At plant base When damage first appears. Flea beetles May-June Sevin, Savit (carbaryl) diazinon 1" 1/2'" Over row as spray When leaves on seedling plants are severely damaged and some plants are being killed. Sod webworm May-June toxaphene 2" At base of plant At time of initial attack. Common stalk borer May-June None labeled Postemergence sprays of carbaryl (Sevin), methomyl (Nudrin, Lannate), chlorpyrifos (Lorsban) may give some control if applied when damage first appears. Hop vine borer May-June None labeled Postemergence sprays of carbaryl (Sevin), methomyl (Nudrin, Lannate), chlorpyrifos (Lorsban) may give some control if applied when damage first appears. 12 Table 4. Field Corn (continued) Insect Thrips Time of attack Insecticide' Pounds of active ingredient per acre Placement Timing of application May-June malathion Metasystox-R (oxydemeton-methyl) 1" On foliage When severe wilting and yellowing of leaves as spray are noticed. Armyworms Chinch bug May-August Sevin (carbaryl) Dylox, Proxol (trichlorfon) ♦Lannate, *Nudrin (methomyl)** malathion 11/2 1 Over row as At first migration, or when worms are eat- spray ing leaves above ear level. June-August Sevin (carbaryl)t Spray at At start of migration from small grains, base of Use only ground equipment and apply 25 to plant 40 gallons per acre. European corn borer, first generation June-July Sevin granules (carbaryl) diazinon granules Furadan granules (carbofuran) Dyfonate granules (fonofos) *Penncap-M spray (micro- encapsulated methyl parathion)t 11/2-2 1-2 1 On upper When 50% or more of the plants have fresh VS of plant whorl feeding, live borers present, and ex- and into whorl tended leaf height is 24 inches or greater. Thuricide granules see (Bacillus thuringiensis) label For suppression. A second application may be needed. European corn Late July, Sevin granules (carbaryl) borer, second mid-August diazinon granules generation Furadan granules (carbofuran) Dyfonate granules (fonofos) *Penncap-M (microencap- sulated methyl parathion)t Thuricide granules {Bacillus thuringiensis) 11/2-2 1-2 1 1 see label Over row Apply at first hatch when there are 100 or more egg masses per 100 plants. Two treat- ments may be necessary because of the ex- tended egg-laying period. Woollybear caterpillars July None labeled Silk clipping caused by caterpillars does not generally warrant control. Grasshoppers June- September Sevin (carbaryl) 1-lVi diazinon V4 Cygon (dimethoate)t Vi malathion 1 Over row As needed. For ensilage corn use Sevin, as spray diazinon, or malathion. Spider mites July-August Di-Syston 15G 1 (disulfoton) Meta-Systox-R Vz (oxydemetonmethyl) Thimet 15G (phorate) 1 Trithion 1 (carbophenothion) ethion 1 diazinon V5 On foliage Begin control if the majority of plants are infested with mites severe enough to cause some yellowing or browning of the lower leaves before dent stage. JapaneJiC beetle July-August Sevin, Savit (carbaryl) 1-2 Over plant During the silking period to protect pollina- tion if less than 75% of plants are silked and three or more beetles are present per ear. Corn leaf aphid July-August malathion diazinon 1 On foliage Apply during late whorl to early tassel 1 when 50% of plants have light to moderate infestations and plants are under drouth stress. 13 Table 4. Field Corn (continued) Insect Time of attack Insecticide" Pounds of active ingredient per acre Placement Timing of application Corn rootworm beetles July-August Sevin, Savit (carbaryl) malathion diazinon Imidan (phosmet) *Penncap-M (microencap- sulated methyl parathion)t 1 1 Vz Vi Va-Vi Overall spray Before 75% of plants have silked, if there or directed are 5 or more beetles per plant and if silk toward ear clipping is observed. Only to protect pollina- zone tion. Southwestern corn borer August Furadan granules (carbofuran) diazinon granules 0\ 1-2 Direct granules over row. Apply when 25% of the plants have egg masses or larvae on leaves. Early-planted corn usually escapes damage. Corn earworm August Sevin (carbaryl) *Lannate, *Nudrin (methomyl)** 1-2 Directed toward Insecticide applications are rarely effective Va-Vi ears for the control of earworms in commercial field corn. Fall armyworm July-September Sevin, Savit sprays 11/4 (carbaryl) diazinon granules 1 Dylox. Proxol spray 1 (trichlorfon) *Lannate, *Nudrin I/2 (methomyl)'' Over row Granules are more effective if worms are deep in whorl. If worms are small and out on leaves, sprays are effective. Treat when 20% of plants have whorl damage and if worms are present. Treatments to control worms in ear tips are not generally effective. * Use restricted to certified applicators only. ** Liquid formulations of Dyfonate, Furadan, Mocap, and Amaze are restricted. Amaze 20G is also restricted. t State labeled insecticide. Applicator must have Illinois label in possession when applying. ^ See Table 14 for insecticide restrictions. '' Based on 40-inch row spacing. Increase rates for narrow rows. ' PPI Pre-plant incorporated. '' To be applied only by experienced operators or those wearing protective clothing. Table 5. Soybeans Insect Time of attack Insecticide' Pounds of active ingredient per acre Placement Timing of application Seedcom maggot Germination diazinon ^ oz. a.i. per bu. On seed At planting time. Bean leaf beetle May-June, August Sevin, Savit (carbaryl) V^-1 Orthene (acephate) i/^-l *Penncap-M (microen- 1 capsulated methyl parathion)*" On foliage When defoliation reaches 30% before bloom or 15% during blooming and pod fill and if beetles are present in the field. If 10% of pods are damaged and leaves are green. Cutworms May-June Sevin bait, Sevin XLR l^i Broadcast (carbaryl) diazinon 2-4 Broadcast PPI During plant emergence if stand has gaps of one foot or more. Thistle caterpillar June Sevin (carbaryl) On foliage When defoliation reaches 30% before bloom and 15% between bloom and pod fill. Mexican bean beetle May-July *Penncap-M (microen- Vz-Va On foliage capsulated methyl parathion)" Orthene (acephate) V2-I *Nudrin, *Lannate (meth- Va-Vz omyl)« Sevin (carbaryl) V2-\ malathion Wz Cygon (dimethoate) Vz See bean leaf beetle (above) for defoliation threshold. 14 Table 5. Soybeans (continued) Pounds of active ingredient Insect Time of attack Insecticide* per acre Placement Timing of application Grasshoppers June-September Cygon (dimethoate)t Sevin, Savit (carbaryl) 1 On foliage When migration into fields begins and de- foliation or pod feeding reaches economic levels. See bean leaf beetle (above). Japanese beetle June-July Sevin (carbaryl) 1 On foliage When defoliation reaches 15% during bloom and pod fill. Green cloverworm July-August Sevin (carbaryl) V2-I *Lannate, *Nudrin (melh- Va-Vi omyl)*^ Orthene (acephate) i/4-l malathion ll/^ Dipel, Thuricide, Bactur (See label) {Bacillus thuringiensis) On foliage When defoliation occurs during blooming, pod set, and pod fill. Usually requires 12 or more half-grown worms per foot of row and 15% defoliation to justify treatment. *Penncap-M (microen- capsulated methyl parathion)" 1/2 '2-/4 Webworms June-August Sevin, Savit (carbaryl) 1 On foliage Requires 15% or more defoliation between bloom and pod fill to justify treatment. Spider mite June-August Trithion (carbophenothion) Yz-Yj, On foliage Cygon (dimethoate) 1/2 As needed on field margins or entire field. Stink bugs July-August Orthene (acephate) *Penncap-M (microen- capsulated methyl parathion)'' *Guthion (azinphos-methyl)' Sevin (carbaryl) Loopers 54-1 V2-VA 1/2 1 On foliage When adult bugs or large nymphs reach 1 per foot of row during pod-fill. Thrips June-August Sevin, Savit (carbaryl) 1 On foliage If seedlings are being seriously damaged and some plants are being killed. Blister beetles July-August Sevin (carbaryl) 1/2-1 On foliage See bean leaf beetle (above) for defoliation threshold. Saltmarsh caterpillar August Sevin (carbaryl) 2 On foliage See bean leaf beetle (above) for defoliation threshold. August Orthene (acephate) i/^-l Thuricide, Dipel, Bactur (See label) {Bacillus thuringiensis) *Lannate, *Nudrin (meth- V^-1 omyl)" On foliage See bean leaf beetle (above) for defoliation threshold. Woollybear caterpillar August None labeled Infestations are rarely economic. Whitefly August- September None labeled High infestations are occasionally present on double-crop soybeans, but are rarely eco- nomic. Corn earworm August- Orthene (acephate) 1 September Sevin (carbaryl) 54 *Lannate, *Nudrin (meth- Va'Vz omyXy *Penncap-M (microencap- 1 sulated methyl parathion)'' On foliage Damage occurs when larvae feed on pods. Apply control if populations exceed 1 per foot of row. * Use restricted to certified applicators only. " See Table 14 for insecticide restrictions. " This product is highly toxic to bees. ° To be applied only by experienced operators or those wearing protective clothing. t State-labeled insecticide. Applicator must have Illinois label in possession at time of application. 15 Table 6. Alfalfa and Clover Insect Time of attack Insecticide"'" Pounds of active ingredient per acre Placement Timing of application Clover leaf weevil March-April malathion 1 On foliage When larvae are numerous and leaf feed- ing is noticeable, usually in early to mid- April. Usually requires 5 or more healthy larvae per crown to justify treatment. Alfalfa weevil March-June (spring treatment for larvae) *Furadan (carbofuran)*-*' i4 *Guthion (azinphos- Yz methyl)" *methyl parathion*^ i/^ *Supracide (methidathion)' I/2 malathion plus 2 qt. per methoxychlor acre Alfa-tox (diazinon plus 2 qt. per methoxychlor) acre Imidan (phosmet) 1 *Penncap-M (microen- i/^ capsulated methyl parathion)* *Lannate, *Nudrin 0.9 (methomyl)' On foliage Refer to circular 1136. Or when 25% of tips are being skeletonized and if there are 3 or more larvae per stem, treat immedi- ately. Do not apply sprays during bloom. Instead, cut and remove the hay. Two treat- ments may be necessary on first cutting. Watch regrowth of second crop for signs of damage, and apply a treatment if feeding damage is apparent. Do not spray alfalfa with Penncap-M during bloom to avoid injury to bees. Alfalfa weevil adults June *Furadan (carbofuran)"''' i^-l On foliage *methyl parathion Yz As a stubble spray. Technically, Guthion, Supracide, Imidan, and Penncap-M could be used, since the labels do not distinguish between alfalfa weevil larvae and adults. Spittlebug Late April, malathion plus methoxy- 2 qt. per May chlor acre malathion 1 Alfa-tox (diazinon plus 2qt. per methoxychlor) acre On foliage When spittle masses are found and nymphs average more than 1 per stem. Variegated May- June Sevin (carbaryl) cutworm Dylox, Proxol (trichlor- fon) W2 On foliage As needed on regrowth of second cutting. Aphids April-August Cygon, De-Fend (dimeth- oate) diazinon malathion *Furadan (carbofuran)''** *Penncap-M (microen- capsulated methyl parathion)* ♦Supracide (methidathion)' 1/2 1 1/4-V/2 1/2 ^2-1 On foliage When aphids are abundant and lady beetle larvae and adults, parasites, and diseases are low. Leafhoppers June-August Sevin, Savit (carbaryl) 1 diazinon Yz *Penncap-M (microen- Y2 capsulated methyl parathion)* Cygon, De-Fend (dimeth- Y2 oate) Dylox, Proxol (trichlor- Vi-1 fon) *Supracide (methida- i/^-l thion)'= Imidan (phosmet) 1 *Furadan (carbofuran)*''' 1 On foliage When second-growth alfalfa is 4 to 5 inches tall, apply a treatment where there are one or more leafhoppers per sweep. Grasshoppers June-September Cygon, De-Fend (dimeth- Yz oate) Sevin, Savit (carbaryl) 1 *Furadan (carbofuran)''** 14 diazinon Y2 On foliage When grasshoppers are small and before damage is severe. Avoid treatments when plants are blooming. Cut the hay and re- move the crop. 16 Table 6. Alfalfa and Clover (continued) Insect Time of attack Insecticide" Pounds of active ingredient per acre Placement Timing of application Webworms July-August Sevin, Savit (carbaryl) 1 Dylox, Proxol (trichlor- 1 fon) malathion plus methoxy- 2 qt. per chlor acre On foliage If damage appears. Fall armyworm August- Sevin (carbaryl) li/z September Dylox (trichlorfon) 1 *Lannate, *Nudrin (meth- 1/2 omyl)" Alfa-tox (diazinon plus 2 qt. per methoxychlor) acre On foliage Usually in late summer or early fall on new seedings or established stands. * Use restricted to certified applicators only. ' See Table 14 for insecticide restrictions. '' Before applying insecticides, be certain to clean all herbicides out of equipment. During pollination, apply very late in day or, if possible, avoid application during bloom. " To be applied only by experienced operators or those wearing protective clothing. '' Only for pure stands of alfalfa. When using no more than \i pound per acre, allow 7 days between application and harvest. If you use 14 to 1/2 pound per acre, allow 14 days to elapse between application and harvest. • This product is highly toxic to bees exposed to direct treatment or residues on crops. Table 7. Non-Crop Areas Insect Time of attack Insecticide" Pounds of active ingredient per acre Placement Timing of application Grasshoppers June- July Sevin (carbaryl) 1 Cygon (dimethoate)t V2 diazinon l/^ malathion 1 On foliage When grasshopper nymphs average IS to 20 per square yard along roadsides, ditch banks, and fencerows. Apply treatments while hop- pers are small and before they migrate into row crops. • See Table 14 for insecticide restrictions. t State labeled insecticide. Applicator must have Illinois label in possession at time of application. Table 8. Grass Pasture Insect Time of attack Insecticide" Pounds of active ingredient per acre Placement Timing of application Grasshoppers June-July *Penncap-M (microen- capsulated methyl parathion)'' diazinon malathion Sevin (carbaryl) On foliage As needed. Armyworms June-July Dylox, Proxol (trichlorfon) malathion Sevin (carbaryl) On foliage As needed. * Use restricted to certified applicators only. " See Table 14 for insecticide restrictions. •" This product is highly toxic to bees. 17 Table 9. Stored Grain (Corn, Wheat, Oats)" Insect Time of attack Insecticide and dilution Dosage Placement Suggestions (See Table 14) Angoumois grain moth (earcorn) April-October (southern i/3 of Illinois only) malathion 57% E.G. 3 oz. per gal. water Apply to runoff Spray surface and sides about May 1 and August 1 Plant tight husk vari- eties. Store as shelled corn to avoid all but surface damage by an- goumois moth. Indian meal moth' April-October dichlorvos 20% (DDVP, Vapona) plastic resin strip" Bacillus thuringiensis" dust 4,000 units per mg. Bacillus thuringiensis" WP 16,000 units per mg. 1 lb. in 10 gal. water 1 strip per 1,000 cubic feet of space above grain mass 1/2 oz. per bu. 0.6 pt. per bu. Attach to ceiling or side wall Apply to top 4 inches of grain Apply to top 4 inches of grain Clean and spray bin with 1.5% malathion to runoff before storage. Store only clean, dry grain. Install strips on May 15 or at storage. Replace strips every 6 weeks between May and October. Apply Bacillus thuringiensis (B.t.) at the auger as the grain is binned.' Note: Level the grain after treat- ment. For emergency treatment use B.t. raked in and the dichlorvos resin strip. Follow label directions for top dress- ing the grain with B.t. GENERAL Internal and ex- ternal feeders Rice and granary weevils Flat grain beetle Saw-toothed grain beetle Rusty grain beetle Foreign grain beetle Cadelle beetle Flour beetles April-October malathion 57% E.G. 1 pt. per 3-5 gal. water^ 3-5 gal. per 1,000 bu. liquid fumigant *"• ' 3-5 gal, per 1,000 bu. *methyl bromide + ^ethylene dibromide '■' As directed Spray uni- formly as grain is binned On surface ; repeat if necessary On surface *aluminum phosphide^ 180 tablets or 300 pellets per 1,000 bu. Glean and spray bin with 1.5% malathion to runoff before storage. Store only clean, dry grain. Protect surface with dichlorvos resin strips or B.t. as recom- mended for meal moths. Glean and spray bin with 1.5% malathion to runoff before storage. ■ Store only clean, dry grain. Apply in late July and September in the southern half of Illi- nois; apply in mid- August in the northern half of Illinois. Protect surface with dichlorvos resin strips or B.t. as recommended for meal moths. Uniformly Fumigants are best used throughout for emergency control of existing infestations. 18 Table 9. Stored Grain (Corn, Wheat, Oats) ^' " (continued) *Use restricted to certified applicators only. " Corn need not be treated if harvested after October 1 unless it is to be carried over after May 15 the following year. Wheat and oats should be treated if they are to be held for one month or more in storage after harvest. Soybeans stored at safe moisture levels are attacked only by Indian meal moth. '' Grain carried over after May 15 of the following year should receive a surface spray of 1.5% malathion at 2 gal. per 1,000 sq. ft. for general feeders and either a B.t. or dichlorvos resin strip application for Indian meal moth control. " Remove webbing before treatment. *• Effective only in enclosed bins. Kills adult moths but not the eggs or larvae. A week or two is required to control effectively an existing infestation. Fumigate the grain if immediate control is desired. Also cleared for use in bins of stored soybeans. * Kills larvae only. A week or two is required to control an existing infestation. Fumigate the grain if immediate control is desired. Cleared for use on soybeans. ' We do not recommend the raked-in method of application for B.t. on grain just going into storage. *Use only the grade of malathion labeled for use on stored grain. Apply after drying, because malathion vaporizes and is lost rapidly when grain is heat dried. *" Some common liquid fumigants are *carbon bisulfide + *carbon tetrachloride, *ethylene dichloride + *carbon tetrachloride, *ethylene dichloride + *ethylene dibromide + *carbon tetrachloride, etc. ' Use with extreme caution. Apply only under calm conditions and when grain temperature is 70° F or above. Grain should be 8 inches be- low the lip of the bin and should be leveled before fumigating. Cover the surface with a plastic tarp for 24 hours, then air out. ' Called the 73 mixture. " Called *Phostoxin or *Detia. Slow vaporization with a 3-day exposure period. Can be used at grain temperature of 60°F or above. Grain should be 8 inches below the lip of the bin and should be leveled before fumigating. Cover the surface with a plastic tarp for 3 days, then air out. Table 10. Small Grains (Barley, Oats, Rye, Wheat) Insect Time of attack Insecticide' Pounds of active ingredient per acre Placement Timing of application Armyworm May-June toxaphene'' Dylox, Proxol (trichlorfon) lYz On foliage When there are 6 or more armyworms Vi-1 per linear foot of row and before extensive head cutting occurs. Do not use trichlorfon on rye. Greenbug, May-June English grain aphid Grasshoppers Fall Cygon (dimethoate) 14 malathion 1 *Penncap-M (microen- 14 capsulated methyl parathion)' On foliage Aphids damage plants indirectly by trans- mitting disease. Once yellowing is notice- able, it is usually too late to treat. Use di- methoate and Penncap-M on wheat only. Fall armjrworm October- November toxaphene*" Dylox, Proxol (trichlor- fon) 2 1/2-1 On foliage During fall when damage to new growth is apparent. Variegated cutworm May-June Dylox, Proxol (trichlor- fon) ^2-1 As needed. Wheat stem maggot May-June None •• ... No chemical control. Damage shows as white heads when field is still green. malathion toxaphene*" Cygon (dimethoate) *Penncap-M (microen- capsulated methyl parathion)' 1 2 1/2 1/2 On foliage During fall when damage is apparent, treat field borders and noncrop areas to stop mi- gration. * Use restricted to certified applicators only. " See Table 14 for insecticide restrictions. •" For use on dairy farms only when alternate material is not available and when insect emergency exists. Do not apply as foliage sprays or dusts to, or adjacent to, dairy pasture, hay, or forage crops. ' This product is highly toxic to bees. 19 Table 11. Grain Sorghum Insect Time of attack Insecticide' Pounds of active ingredient per acre Placement Timing of application Cutworms May-June Sevin (carbaryl) Over row When seedling plants are being cut. Yellow sugarcane May-June aphid Metasystox-R \i-V2 (oxydemeton-methyl) Over row Treatment should be applied at first sign of damage to seedling sorghum ; 5 to 10 aphids per leaf. Greenbug June-July Cygon, De-Fend (dimetho- ate) malathion diazinon Meta-Systox-R (oxydemetonmethyl) V4-1/2 1 V2 Over row When greenbug damage is sufficient to cause death of more than 2 normal-sized leaves before the hard-dough stage. Grasshoppers June-August Cygon (dimethoate) Vz Over row As needed. Fall armyworm July-August Sevin (carbaryl) *Lannate, *Nudrin (methomyl)" V^-Vz Over row When there is an average of 2 worms per head. Leaf feeding or whorl damage is seldom economic. Web worms After heads form Sevin, Savit (carbaryl) *Lannate, *Nudrin (methomyl)" 1-2 1/2 Over row When 10 to 25% of the heads are infested with 5 or more larvae per head. Corn earworm After heads form Sevin, Savit (carbaryl) *Lannate, *Nudrin (methomyl)" 1-2 Over row When there is an average of 2 worms per head. Sorghum midge August- September Cygon (dimethoate) diazinon Sevin (carbaryl) *Lannate, *Nudrin (methomyl)" 14 14-1/2 11/4 Over row Apply during bloom when 50% of heads have begun to bloom and there are 1 or more midge adults (flies) per head. Corn leaf aphid July- September Cygon (dimethoate) 14 malathion 1 Over row Corn leaf aphids rarely cause economic damage unless populations are heavy and drouth conditions exist. * Liquid formulations are restricted to certified applicators only. ' See Table 14 for insecticide restrictions. " To be applied only by experienced operators or those wearing protective clothing. Table 12. Sunflowers Pounds of active ingredient Insect Time of attack Insecticide" per acre Placement Timing of application Cutworms May-June toxaphene 1^2-2 Over row WTien 10% of the seedlings are damaged. Sunflower beetle May-June toxaphene lVi-2 Over row When defoliation reaches 25%. Do not ap- ply toxaphene after yellow ray petals have formed. Thistle caterpillar June toxaphene 1^-2 Over row When defoliation reaches 25%. Grasshoppers June-August toxaphene lVi-2 Over row When defoliation reaches 25%. Sunflower moth larvae July Thiodan, Tiovel 1 (endosulfan) ♦Supracide (methidathion)" V4 Over row Apply first treatment when a field has reached 20 to 25% bloom and moths are present. * Use restricted to certified applicators only. • See Table 14 for insecticide restrictions. " To be applied only by experienced operators or those wearing protective clothing. Spraying blossoming sunflowers can be extremely hazardous to bees. Coordinate with local beekeepers before applying sprays. 20 Table 13. Relative Toxicities of Commonly Used Agricultural Insecticides Trade Chemical Acute name name oral Amaze isofenphos high Counter terbufos high Cygon, De-Fend dimethoate moderate Diazinon diazinon moderate Dipel, Bactur, Thuricide Bacillus thuringiensis very low Di-Syston disulfoton high Dyfonate fonofos high Dylox, Proxol trichlorfon low Ethion ethion high Furadan carbofuran high Guthion azinphosmethyl high Imidan phosmet moderate Lannate, Nudrin methomyl high Lorsban chlorpyrifos moderate Malathfon malathion low Metasystox-R oxydemetonmethyl moderate Methoxychlor methoxychlor low Methyl parathion methyl parathion high Mocap ethoprop moderate Orthene acephate moderate Penncap-M microencapsulated methyl parathion moderate Sevin carbaryl low Supracide methidathion high Thimet phorate high Thiodan endosulfan high Toxaphene toxaphene moderate Trithion carbophenothion high Toxicity to mammals" Acute dermal Birds high high moderate moderate very low high moderate low high moderate moderate low moderate moderate low moderate low high high moderate low low moderate high high moderate high high high moderate high very low moderate moderate low low moderate moderate low low moderate low moderate very low moderate moderate moderate moderate very low moderate moderate low low Toxicity to Fish high very high very low high very low very low moderate very high very high moderate very high very low low very low very low high very high very high Bees high high very low moderate low very low high high high high high high moderate low high moderate high high high high moderate moderate low moderate * Relative toxicities based on acute oral and acute dermal LD50 values of technical insecticide. Table 14 follows on pages 22 and 23. 21 Table 14. Limitations in Days Between Application of the Insecticide and Harvest of Crop and Restrictions on Use of Insecticides for Field Crop Insect Control (Blanks denote that the product is not suggested for that specific use in Illinois) Worker Field corn re-entry ne (hours)" Grain Ensilage and stover Sorghum Forage crops tir Alfalfa Clover Pasture ♦Amaze (isofenfos)'' 75,A 75,A Counter (terbufos) . , . B B Cygon, De-Fend (dimethoate) . . . 14 14 28 'io,c ... Diazinon B 10 7 7 7 "6 **Di-Syston (disulfoton)"'" ... 40 40 **Dyfonate (fonofos)'' ... 45 45 Dylox, Proxol (trichlorfon) . . . D D . • • "o "6 6 Ethion 24 50, E 50,E . . . ... **Furadan (carbofuran)'' • . . B,F F,G . . . 7,H *Guthion (azinphos-methyl)"' ^ 24 16,C i6,C Imidan (phosmet) ... 14 14 7,C **Lannate (methomyl)"'" . . . 0 3 14 7 Lorsban (chlorpyrifos) . , , 50 SO ... Malathion • • • 5 5 7 0 6 "o Metasystox-R 48 7 7 45 > > ■ • • . ... (oxydemeton-methyl) Methoxychlor ... 7 7 *Methyl parathion'" 48 • • ■ . . . 15 15 **]\Iocap (ethoprop)'' • . . B B . . . . . . - . • • • • **Nudrin (methomyl)''" B 3 14 7 . . . . . • *Penncap-AI (microencapsulated . . . 12 12 . , . 15 . . . IS methyl parathion)"-'' Sevin, Savit (carbaryl) ... B,I B,I 21 0 0 0 *Supracide (methidathion)'' . . . . . . 10.J . . . . . . Thimet (phorate) 30,K *36,K . . . . . . • . ■ Thuricide (Bacillus . . . B B . . . ... • . . . . . thiiringiensis) Toxaphene B L Trithion (carbophenothion) 48 21 21 ... ... ... ... Sun- Barley Oats Rye Wheat Soybeans flowers Cygon (dimethoate) 60 21 Dipel, Thuricide, Bactur 0 ( Bacillus thuringiensis) Diazinon . . . M Dylox (trichlorfon) 21 21 21 . . . *Guthion (azinphos-methyl)^'' 24 . . . . . . 45.N **Lannate (methomyl)"-'' . . . . . . 14 Malathion **7 '*7 7 7 3 **Nudrin (methomyl)"' '' . . . 14 Orthene (acephate) . . . 14,N *Penncap-M (microencapsulated . . . "is 20,P methyl parathion)"'" Sevin (carbaryl) . . . 0 *Supracide (methidathion)'' 50,N Thiodan, Tiovel (endosulfan) 0,Q Toxaphene R R R "r S Trithion (carbophenothion)'' '' 48 ... ... ... ... 7,N ... 22 Table 14. Limitations (continued) A. Do not use for forage, fodder, or ensilage or harvest fresh com (including sweet corn) or corn grain within 75 days of last application. Do not make a second application to sweet corn. Crops other than corn should not be planted in fields within 18 months of the last application of Amaze. B. No specific restriction when used as recommended. C. Apply only once per cutting, and do not apply during bloom. D. Three applications may be made per season. Can be applied up to harvest. E. Do not make more than 1 application after ear formation. Do not feed treated forage to livestock. F. Do not plant crops other than alfalfa, corn, peanuts, peppers, potatoes, rice, sorghum, strawberries, sugar beets, sugarcane, and tobacco within 18 months of last application. Soybeans and oats may be planted the following season. Any other crop may be planted, if it is not harvested or grazed. G. Do not make a foliar application if Furadan 10 granules were applied at more than 10 pounds per acre at planting. Do not make more than two foliar applications per season. H. Make no more than one application per season. I. Do not apply granules within 7 days of harvest. J. Make no more than one foliage and one stubble application per cutting. K. Besides treatment at planting, one more application can be made at cultivation or over the corn later in the season. L. Do not feed treated forage to dairy animals. Do not feed sprayed forage or granular-treated corn silage to livestock fatten- ing for slaughter. Do not graze meat animals on granular-treated stover within 28 days of slaughter. M. Diazinon is labeled only as a preplant broadcast treatment. N. Do not graze or feed treated vines to livestock. P. Do not apply more than 2 applications per season. Q. Do not feed treated forage to livestock. Do not exceed 3 applications. R. Do not graze or feed treated forage to dairy animals or to animals being finished for slaughter. S. Do not apply after the yellow petals have formed on the flower heads. Do not feed forage to livestock. Do not apply more than 2 times per season. * Use restricted to certified applicators only. ** Liquid formulations are restricted. ° Workers should be warned in advance of treatments. Workers may not enter fields treated with the insecticides without wearing protective clothing for the intervals indicated. They may not enter a field treated with other insecticides without protective clothing until the spray has dried or the dust has settled. Protec- tive clothing includes a hat, long-sleeved shirt, long-legged pants, and shoes and socks. " Sprays to be applied only by experienced operators wearing proper protective clothing. The suggestions given in this circular are revised annually by entomologists of the College of Agriculture and the Illinois Natural History Survey. Issued in furtherance of Cooperative Extension Work, Acts of May 8 and June 30, 1914, in cooperation with the U.S. Department of Agriculture. WILLIAM R. OSCHWALD, Director, Cooperative Extension Service, University of Illinois at Urbana-Champaign. The Illinois Cooperative Extension Service provides equal opportunities in programs and employment. 18M— 10-80 — 49293— SR 23