I Q. r 630.7 | i*6c no.899 198© UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN ACES /k*X 1986 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 clas- sifying pesticides for "general" or "restricted" use. Only a few pesticides have been classified (Table 1). Commercial applicators who apply restricted-use pes- ticides must be certified. Commercial applicators include persons applying a pesticide for hire and governmental 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 Department of Public Health. Private applicators who use restricted-use pesticides "for the purpose of producing any agricultural com- modity 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 exami- nation. Educational training programs for farmers (private applicators) and commercial pesticide applicators are conducted by the Cooperative Extension Service to prepare persons for certification. For additional infor- mation, consult your county Extension adviser in agri- culture. The actual certification and the issuing of permits or licenses are handled by the Illinois Depart- ment of Agriculture or the Illinois Department of Public Health. Insecticides and Classifications At the time this publication was in preparation, several of the insecticides listed below had been recently classified for "restricted" use by the EPA. Granular formulations of Counter, Di-Syston, Dyfonate, Furadan, Mocap, and Thimet that were released for shipment by the manufacturer after September 1, 1985, must be labeled as restricted-use products. The chemical names used in this circular may be unfamiliar to you. These names are the common, coined chemical names and as such are not capitalized (for example, terbufos). Trade names are capitalized (for example, Counter). In the table of limitations (Table 13), the trade names are listed first, with the common name in parentheses following the trade name. In the tables of suggestions, only the trade name is listed. Table 1. Insecticide Classifications Common name Trade name Classification acephate Orthene unclassified Bacillus thuringiensis Dipel, Thuricide, unclassified Bactur, SOK carbaryl Sevin unclassified carbofuran * Furadan restricted3 carbophenothion Trithion unclassified chlorpyrifos Lorsban unclassified diazinon Diazinon unclassified dimethoate Cygon unclassified disulfoton * Di-Syston restricted3 ethion Ethion unclassified ethoprop * Mocap restricted" fenvalerate *Pydrin restricted flucythrinate * Pay-Off restricted fonofos * Dyfonate restricted* malathion Cythion, malathion unclassified methidathion *Supracide restricted methomyl *Lannate, *Nudrin restricted1" methoxychlor methoxychlor unclassified methyl parathion *Methyl parathion restricted methyl parathion *Penncap-M restricted (microencapsulated) permethrin *Ambush, *Pounce restricted phorate * Thimet restricted3 phosmet Imidan unclassified terbufos *Counter restricted" t rich lor fon Dylox unclassified trimethacarb Broot unclassified a All granular formulations released for shipment by the manufacturer after September 1, 1985, are restricted. b All formulations except water-soluble packages, 25% wettable pow- der, and granulars are restricted. Asterisks (*) are used throughout this circular to indicate insecticides classified for "restricted" use. UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN COLLEGE OF AGRICULTURE COOPERATIVE EXTENSION SERVICE In cooperation with ILLINOIS NATURAL HISTORY SURVEY CIRCULAR 899 (revised annually) November, 1985 Special Local Need Registrations Section 24(c) of the amendments to the Federal Insecticide, 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 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. 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 insecticides registered for crop pests are included in this circular. Insecticides that are effective and do not present an undue hazard to the user or the environment are suggested whenever possible. Trade names have been used for simplicity, but their usage does not imply the endorsement of one product over another, nor is discrimination intended against any product. This guide for insect control is based on research results from the Illinois Natural History Survey, the University of Illinois Agricultural Experiment Station, other experiment stations, and the U.S. Department of Agriculture. 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 new labels and changes in recommendations through the news media to keep you up to date. REFERENCES Fact sheets (designated by NHE numbers) discussing nonchemical control methods, descriptions of specific insects, and their life history and biology can be obtained from the office of the county Extension adviser in agriculture or by writing to Entomology Extension, 172 Natural Resources Building, 607 East Peabody Drive, Champaign, IL 61820. PEST-MANAGEMENT SCOUTING PROGRAMS Integrated Pest Management (IPM) is a systematic method of looking for pests in the field, of determining whether any control measures are needed, and if there is a problem, of deciding on the proper measures to use. Pest scouting enables farmers to detect and control pest outbreaks before significant yield losses occur. Be- cause decisions on chemical control are based on eco- nomic thresholds, IPM programs eliminate unnecessary pesticide use. Pest scouting has been accepted as an important management tool by many Illinois farmers. As farming costs increase, growers are realizing the advantages of treating a field only when an economically harmful pest population occurs, rather than treating it automatically regardless of the situation. By using pesticides on this basis, farmers have a better chance of reducing man- agement costs. Pest scouting programs have been initiated by several pest-management consulting firms throughout the state. In addition to pest scouting, most offer other services such as soil testing and nematode monitoring. PESTICIDE SAFETY Certain precautionary steps should be taken when handling insecticides. The insecticides suggested in this publication can be poisonous to the applicator. The farmer or applicator 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. Ob- serve 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 person most likely to suffer ill effects from insecticides is the applicator. Accidents and careless, needless overexpo- sure can be avoided. Following these rules will prevent most insecticide accidents: 1. Wear rubber gloves when handling insecticide concentrates. 2. Do not smoke, eat, or drink 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 con- tainers with the labels on them. 5. Store insecticides out of the reach of children, irresponsible persons, and animals; store preferably in a locked building. Do not store near livestock feeds. Better yet, buy no more pesticide than you will use, thus elimi- nating 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 surfaces or apply insecticides near dug wells or cisterns. 11. Do not apply insecticides, except in an emer- gency, to areas with abundant wildlife. 12. Do not spray or dust when weather favors drift. 13. To avoid bee kill, apply insecticides after bee activity has been completed for the day; use the least toxic materials. Warn beekeepers that you are applying insecticides. Refer to the Illinois Pesticide Applicator Study Guide for more information concerning safe handling of pes- ticides and treatment of pesticide poisoning. POTENTIAL FOR SOIL INSECT PESTS IN CORN There are many factors that affect soil insect popu- lations and their potential to damage corn. The type of crop rotation greatly influences whether a soil insect problem will occur and what kind it will be. Weather, weeds, soil type, planting date, hybrid, tillage, and natural enemies also influence insect populations. Knowl- edge about soil insect damage in a particular field during previous years is also helpful because infestations tend to occur in the same fields and in the same area. Illinois Extension entomologists have estimated the probability of the occurrence of soil insect pests in corn on the basis of cropping sequence (Table 2). These estimates can serve as a guide to determine the risk of damage caused by soil insects and the need for applying a soil insecticide at planting. Corn After Soybeans. The potential for soil insect problems in corn after soybeans is generally low, and the use of soil insecticides rarely pays. Corn rootworms rarely cause damage to corn after soybeans. In most fields, a diazinon + lindane planter-box seed treatment will be adequate to protect against attack by seedcorn beetles, seedcorn maggots, and wireworms. Scout the field for cutworm damage as the plants emerge from the soil. White grubs are an occasional problem in corn after soybeans. Corn After Corn. The potential for rootworm damage is moderate to severe wherever corn follows corn in Illinois. A rootworm soil insecticide may be needed in most fields of corn after corn. Wireworms are occasion- ally a problem in the southern part of Illinois. Scout for cutworm damage. Corn After Grass Sod. Wireworms and white grubs are potential problems. Apply a labeled soil insecticide at planting time. Scout for cutworm damage. Corn After Sorghum. A planter-box seed treatment of diazinon or diazinon + lindane will protect the corn seeds against seedcorn maggots. Scout the fields for cutworms as the corn emerges. Corn rootworms are rarely a problem where corn follows sorghum. Corn After Legumes. Cutworms, grape colaspis, grubs, and wireworms occasionally damage corn planted after clover and alfalfa. In addition, adult northern corn rootworms are sometimes attracted to legumes or to blooming weeds in legumes for egg laying, particularly in years when beetles are forced to leave adjacent fields of drouth-stressed corn to seek food. A soil insecticide should be considered for this cropping sequence. Corn After Small Grain. There is a slight potential for damage by wireworms, seedcorn beetles, and seed- corn maggots in corn after small grain, particularly wheat. In most instances, a diazinon + lindane planter- box seed treatment will be adequate. If wireworms are present, use a soil insecticide at planting time. Excessive Table 2. Probability Estimates of Economic Soil Insect Damage in Corn and Suggestions for Control According to Cropping Sequence, Illinois Crop preceding corn Insect pest Need for a soil insecticide Wireworm Cutworm Corn rootworm White grub Seedcorn maggot Billbug Grape colaspis Recommended pest management practices Soybeans 1:500 1:25 1:10,000 1:1,000 1:150 1:100 1:1,000 very low Use planter-box seed treatment; scout tor cutworms. Corn 1:200 1 : 1 00 2:3 1:1,000 1:50 1:100 1:5,000 mod-high Scout for rootworm beetles; treat corn if population exceeds 1 per plant at any time during August. Small grain 1:100 1:50 1:100 1:250 1:50 1:200 1:5,000 low Bait for wireworms prior to plant- ing. Legume 1:25 1:25 1:50 1:150 1:10 1:50 1:4 low-mod Bait for wireworms prior to plant- ing. Grass sod 1:10 1:25 1:500 1:10 1:25 1:50 1:1,000 mod-high Use soil insecticide Foi wireworms and white grubs; it no-till, scout tor loli.ii inse< i damage .is torn emerges. weed cover in small grain stubble fields may have been attractive to northern corn rootworm beetles for egg laying as the beetles moved from adjacent fields of drouth-stressed corn. CORN ROOTWORM SITUATION Problem Area Populations of northern and western corn rootworm beetles were extremely high in 1985. Although the potential for rootworm damage to corn following corn is greatest in the northern two-thirds of the state, moderate to severe damage to corn roots by larvae may occur in any field where corn follows corn in Illinois. Rootworm Control Problems, 1985 Corn rootworm larval control with soil insecticides was erratic in Illinois during 1985, in both farmers' fields and research trials. Instances of poor control were observed with all rootworm soil insecticides, carbamates and organophosphates, over a wide geographical area with various soil types and weather conditions. An investigation of some of the problem fields has disclosed several factors that probably contributed to poor control with the insecticides. The factors that stand out but are not easily quantifiable include dry soil conditions during May, June, and July, above-average rootworm larval populations, and improper calibration of insecticide ap- plications (rates that were too low). In some fields, lack of rain prevented the movement of the insecticide from the soil surface or off the granular carrier to the area where rootworm larvae were feeding. Early planting also may have been a contributing factor in some fields because soil insecticides applied in April could have lost much of their potency by the time eggs hatched. Undoubtedly, several of these conditions in combination could have affected the performance of soil insecticides. Unfortunately the factors that influence the perfor- mance of soil insecticides under field conditions are not well understood. Recent research indicates that the breakdown of some soil insecticides by soil microorgan- isms is accelerated after repeated applications of the same compound. The soil microorganisms use the in- secticide as an energy source. As a result, the insecticide has a progressively shorter residual time in the soil. This seems to be most prevalent in fields where the same soil insecticide has been used for several consecutive years; however, the pattern is neither clearcut nor predictable. In all probability, environmental conditions combined with accelerated degradation of the insecticides by mi- croorganisms are major causes for rootworm control problems. Are the rootworms more tolerant to the soil insec- ticides? Although this has not been confirmed, some research data suggest that some slight change in suscep- tibility has occurred with some compounds. Unfortu- nately most tests to detect resistance are conducted with the adult stage rather than the damaging larval stage. So at this point, tolerance to insecticides cannot be ruled out. Determining Potential for Damage in 1986 Corn growers should base the need for using a rootworm soil insecticide in 1986 on the abundance of rootworm beetles in cornfields during late summer of 1985. Generally, if beetle numbers reached or exceeded 0.75 per plant at any time during late July, August, or September, 1985, plan to apply a rootworm soil insec- ticide if the field is to be replanted to corn in 1986. However, if the field scouted in 1985 was corn following any crop other than corn, the threshold (bee- tles per plant) is lower. The ratio of female to male beetles in first-year corn is usually higher than in con- tinuous corn. The females apparently migrate into first- year cornfields, so most of the beetles found there are females. As a consequence, the threshold for determin- ing whether to rotate away from corn or to use a soil insecticide in 1986 may be as low as 0.5 beetle per plant. Fields of corn planted in late May or June, 1985, may have extensive rootworm damage if replanted to corn in 1986. 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. Planting the fields to a crop other than corn in 1986 is suggested to reduce the rootworm population. SUGGESTIONS FOR ROOTWORM CONTROL, 1986 In recent years, the performance of rootworm soil insecticides has been quite variable. They have per- formed effectively at some locations and have been marginal or ineffective at others. This trend could continue in 1986. An immediate solution to the phe- nomenon of erratic rootworm soil insecticide perfor- mance is not readily available. Perhaps there is none. It is entirely possible that changes brought about by treat- ing millions of acres of corn with soil insecticides over the past 20 years have introduced an era when rootworm control with current soil insecticides will be highly variable. Looking to 1986, you should seriously consider crop rotation, particularly in fields where there is a high probability of rootworm damage. Other alternatives include applications of a soil insecticide at planting or at cultivation. Considering the erratic performance of planting-time treatments in 1985, a cultivator applica- tion in early June near the beginning of rootworm egg hatch should be an effective option. However, for most farmers planting time treatments of a soil insecticide will be the predominant method of rootworm control. If you use a soil insecticide at planting, plan to check fields in early to mid June to determine whether damage is occurring. If so, a cultivator application may be needed. Crop Rotation Crop rotation is an extremely effective way to prevent damage by northern and western corn rootworm larvae. If feasible, do not grow corn two years in succession in the same field. First-year corn following soybeans will generally not require a soil insecticide for rootworm control. 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 rootworm damage in corn follow- ing soybeans. Soybean fields with 5,000 or more vol- unteer corn plants per acre will usually warrant treat- ment for rootworm control the following year if planted to corn. 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 broadleaf weeds. Consequently, when a crop other than corn, soybeans for example, is planted in a field with soil containing millions of rootworm eggs, the rootworm larvae die before becoming egg-laying beetles. Soil Insecticides The suggestions for rootworm control that follow are based on research conducted by entomologists in Illinois and other states. At Planting. Apply Broot 15GX, Counter 15G, Dy- fonate 20G or 4EC, Furadan 15G or 4F, Lorsban 15G, Mocap 15G, or Thimet 20G at the suggested rate (see Table 3). IMPORTANT: Read the suggestions in the section on alternating rootworm soil insecticides. The rates suggested in Table 3 should not be ex- ceeded for rootworm control. Research has shown that increasing the rates of soil insecticide application does not improve rootworm control. Increasing the rate of the product will not solve rootworm control problems and may even accelerate the onset of resistance in the rootworm population. Proper calibration, placement, and incorporation of rootworm soil insecticides will improve the likelihood of good control. See the section "Calibration for Gran- ular Soil Insecticides" in this circular. With the exception of Mocap, the soil insecticides are labeled for application in a 7-inch band ahead of the planter press wheel or firming wheels. Counter 15G and Furadan 15G can also be applied in the seed furrow for rootworm control. Mocap 15G is labeled for application behind the press wheel or firming wheels. All insecticides should be lightly incorporated with spring tines or drag chains mounted behind the planter units. Soil insecticides will give 50 to 70 percent control of corn 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 pollination. Planting-time treatments applied in early April may provide only marginal control. Consider a cultivator Table 3. Soil Insecticides Suggested for Rootworm Control, Illinois, 1986 Time of application Ounces of product per 1,000 ft. of row Amount of product needed per acre Insecticide3 40" rows 38" rows 36" rows 30" rows Broot 15GX At planting 8 6.7 lb. 7.0 lb. 7.4 lb. 8.7 lb. ♦Counter 15G At planting or cultivation 8 6.7 lb. 7.0 lb. 7.4 lb. 8.7 lb. *Dyfonate 20G *Dyfonate 4E *Dyfonate 4E *Furadan 15G At planting or cultivation At planting Prepiant At planting or cultivation 6 2.4 fl. oz. Broadcast 8 5.0 lb. 2 pints 3 quarts 6.7 lb. 5.3 lb. 2'/s pints 3 quarts 7.0 lb. 5.6 lb. 2lA pints 3 quarts 7.4 lb. 6.7 lb. 2%M pints 3 quails 8.7 lb. *Furadan 4F Lorsban 15G Lorsban 4E *Mocap 15G At planting or cultivation At planting or cultivation At cultivation At planting or cultivation 2.4 fl. oz. 8 2.4 fl. oz. 8 2 pints 6.7 lb. 2 pints 6.7 lb. 2'/s pints 7.0 lb. 2% pints 7.0 lb. 2V* pints 7.4 lb. 2V* pints 7.4 lb. 2Vi pints 8.7 lb. 2'/4 pmis 8.7 lb. *Thimet 20G At planting or cultivation 6 5.0 lb. 5.3 lb. 5.6 lb. 6.7 lb. a Consult text for more information. LIQUID FORMULATIONS ARE HIGHLY TOXIC. * Use restricted to certified applicators only. application in late May or early June in such fields, rather than a treatment at planting time. Liquid formulations. Dyfonate 4E or 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. Incompatibility or crop injury may be a problem in treatments using a liquid insecticide with a liquid fertil- izer 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 insecticide formulations. At Cultivation. Apply Counter 15G, Dyfonate 20G, Furadan 15G or 4F, Lorsban 15G or 4E, Mocap 15G, or Thimet 20G 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 treatment of a soil insecticide by cultivator is in late May or early June, near the beginning of egg hatch. A cultivation-time application of a soil insecticide is an alternative to a planting-time application or may be used as a "rescue" treatment if the planting-time insec- ticide fails to control rootworm larvae. In either case, you should dig up several plants and examine the roots and surrounding soil for rootworm larvae and damage. If you find 3 or more larvae per plant and the field was not treated at planting, a cultivator application is war- ranted. If the field was treated at planting and rootworm larvae and damage are obvious in June, plan to apply a cultivator treatment. "Obvious" rootworm damage is characterized by brown root tips and roots that have been tunneled in or chewed back toward the base of the plant. Soil moisture may affect both application and effec- tiveness of cultivation-time treatments. Fields that are too wet may never be cultivated. On the other hand, the insecticide may not perform satisfactorily if the soil is too dry. Suggestions For Alternating Rootworm Soil Insecti- cides. Avoid using the same insecticide in consecutive years or in fields where it has had recent performance problems. The continuous use of one insecticide may enable soil microorganisms to break it down rapidly or may hasten the onset of insect resistance. Illinois ento- mologists encourage growers to consider alternating rootworm soil insecticides, rather than using one product for several consecutive years. Consider the following suggestions for alternating rootworm soil insecticides: 1 . If performance of a soil insecticide has been poor in a particular field in recent years, do not use the same insecticide in that field in 1986. 2. Consider alternating organophosphate (Counter, Dyfonate, Lorsban, Mocap, and Thimet) and carbamate (Broot and Furadan) soil insecticides. Keep in mind, however, that growers generally have had no advance warning of poor control where problems have occurred. 3. Avoid using carbamates in consecutive years. 4. Avoid using the same organophosphate in consec- utive years. Laboratory and field research indicates that using the same rootworm soil insecticide for several consec- utive years can eventually lead to erratic, if not poor, rootworm control. This first became apparent in Illinois during the mid-1960s when northern and western corn rootworms developed resistance to aldrin and hepta- chlor, about 5 years after these compounds were first used in the field. Buxten, a carbamate soil insecticide introduced in 1967, gave good rootworm control until the early 1970s, but was dropped from University of Illinois's recom- mendations in 1974 after problems with control had developed. Furadan, also a carbamate soil insecticide, was used by many farmers with excellent results from 1969 until 1975 when control became erratic. More recently, Amaze, an organophosphate that had provided excellent rootworm control in research trials, was re- moved from the soil insecticide market by the manu- facturer following poor rootworm control in 1983 — only 3 years after being registered. A lesson to be learned from the preceding scenario is that extensive and continuous use of any one com- pound may contribute to erratic results and to its eventual failure. Control of Rootworm Beetles to Prevent Egg Laying Research conducted during the mid 1970s indicated that properly timed sprays to prevent rootworm beetles from laying eggs could eliminate the need for a soil insecticide the following year. However, the procedure is not foolproof. Factors beyond the control of the operator, such as beetle migration and weather, may minimize the treatment's effectiveness. Growers who have experienced erratic rootworm control with soil insecticides the past few years and who are committed to a continuous corn program may look to beetle control as an alternative, or an addition, to soil insecticides at planting. Ideally, one properly timed spray should replace a soil insecticide. Unfortunately, some fields will require two sprays to combat extended beetle emergence and egg laying. Two sprays or a spray plus a soil insecticide the following season may hasten the onset of rootworm resistance to insecticides. A rootworm beetle suppression program should be employed only if the fields are under the supervision of trained pest management personnel in weekly scouting programs. Careful field scouting is a requirement. Summary: Planning Your Rootworm Control Program A management plan for rootworms should be long range (not a year at a time) and include crop rotation, insecticide rotation, cultivator treatments, and scouting to determine the need for rootworm control. 1. Alternate corn with another crop when possible, particularly in fields where rootworm beetles averaged 0.75 or more per plant last summer, or if the soil insecticide did not give effective rootworm control in 1985. 2. If you intend to grow corn after corn and root- worm beetles averaged 0.75 or more per plant in corn after corn or 0.5 beetle per plant in first-year corn last summer, apply a rootworm soil insecticide at planting time. Apply the rate suggested in Table 3 and consider our suggestions for alternating rootworm soil insecti- cides. 3. Consider a cultivation-time application of a root- worm soil insecticide if you intend to plant in early April or if your planting-time insecticide does not provide effective control. 4. Scout for rootworm beetles in July and August, 1986, to determine the potential for rootworm larval damage in 1987. Scouting to Determine Rootworm Potential in 1987 The abundance of rootworm beetles in a cornfield in July and August is an excellent indicator of future rootworm problems. Corn growers can determine the potential for rootworm damage in 1987 by counting western and northern corn rootworm beetles from mid- July through August, 1986, in this way: 1 . Make 3 or more counts for western and northern corn rootworm beetles at 7- to 1 0-day intervals between mid-July and late August in fields to be replanted to corn. 2. Examine 5 plants selected at random in each of 10 areas of the field. Count all of the western and northern corn 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 disturbing 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 0.75 beetle per plant in corn after corn or 0.5 beetle per plant in first-year corn for any sampling date, plan to rotate away from corn or apply a rootworm soil insecticide to corn in 1987. If populations do not exceed an average of x/i beetle per plant for any sampling date, a soil insecticide will not be needed the following season. Rootworm Life Cycle Western and northern corn rootworm beetles deposit their eggs in the soil at the base of the corn plants or between rows during August and September. The eggs overwinter 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 during June, July, and August. When a larva is fully grown (V2 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 devel- opment 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 before 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 The occurrence and extent of cutworm infestations are difficult to predict each year. Sandhill, dingy, and claybacked cutworms all overwinter in Illinois as partially grown larvae, but their populations are seldom wide- spread. As a result, they cause damage early in the growing season in scattered areas. Sandhill cutworms are a problem in sandy areas almost every year. Dingy and claybacked cutworms occur more frequently in corn planted after sod or forage legumes than in other crop rotations. Black cutworms do not overwinter in Illinois, so out- breaks are difficult to forecast. Infestations of black cutworm larvae arise from eggs laid by moths that fly into Illinois in the early spring. A statewide program of monitoring black cutworm pheromone traps provides information about the time and intensity of spring moth flights. Certain factors favor black cutworm outbreaks. The most important factors may be late planting and preplant weed infestations. Fields that are tilled and 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. Currently, two options are available for cutworm control: applications of soil insecticides to prevent dam- age and rescue treatments after the infestation appears. Because of the uncertainty in predicting which fields will have light, moderate, or heavy infestations of cutworms, it may be more feasible to use rescue treatme?its for cutworm outbreaks rather than to use a preplant or planting-time treatment unnecessarily. Based on the relatively low incidence of cutworm problems over the past 25 years, a grower may find an economic advantage to the wait-and-see system, which involves field scouting rather than a costly always-applv 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 Ambush, Lorsban, Pay- Off, Pounce, or Pydrin, or Sevin pelletized bait. Broad- cast the pelletized bait on the surface, but do not incorporate. Ambush, Lorsban, Pay-Off, Pounce, and Pydrin sprays should also be broadcast. The keys to effective cutworm control with the rescue treatments are the amount of surface moisture and the movement of the worms. Control may be poor, regard- less of the insecticide used, if the topsoil is dry and crusted and the worms are working below the soil surface. When the soil is dry, the high rate of Ambush, Lorsban, Pay-Off, Pounce, or Pydrin is recommended. To determine the need for rescue treatments, scout the fields during plant emergence, particularly those fields considered 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 lA 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 are relatively effective in con- trolling light to moderate infestations, but control may be unsatisfactory for heavy infestations. Lorsban 15G, Mocap 15G, Dyfonate 20G, Counter 15G, and Furadan 15G are registered for the control of cutworms in corn. Lorsban 15G has provided the best cutworm control in research trials. The Mocap and Dyfonate labels state that under heavy infestations of cutworms, enough cutworms may survive to cause some crop damage, so a rescue treatment may be necessary. Counter and Furadan are labeled for "suppression of cutworms." In fields with a history of cutworm problems or in high-risk fields, Lorsban 15G should give the most consistent control of cutworms. Pre-emergent sprays of Ambush, Pounce, and Pydrin may be applied in fields where the probability of cutworm damage is great. Preplant broadcast treatments of Lorsban 4E and Dy- fonate 4E are also registered for corn cutworm control. Lorsban is labeled at rates of 1 to 2 quarts per acre; the higher rate is suggested. Dyfonate 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 application. Replanting may be required if cutworm damage is extremely severe. Before replanting apply Lorsban 4E as a broadcast spray at 3 to 4 pints per acre, and incorporate the insecticide into the top 2 to 4 inches of soil. Or you can apply a labeled granular insecticide. If the cutworm infestation is heavy, the Lorsban spray will be more effective. WIREWORMS Wireworms may attack the seed or drill into the base of the stem below ground level, damaging or killing the growing point. Damage will show up as wilted, dead, or weakened plants and spotty stands. Wireworm larvae are yellowish-brown and wirelike; several species are known to attack corn. They live for two to five years in a field in the larval stage, feeding on the roots of grasses and crops. Their presence is often related to the crops or weeds that were in the field two to four years before damage to the corn. Most reports of damage to corn have been in fields where corn follows soybeans or where there has been a corn-soybean-small grain rotation. The adult (a click beetle) prefers to deposit its eggs in small-grain stubble or in grassy fields. Attempts to control wireworms with an insecticide rescue treatment after the damage appears are not very successful. Therefore, if an infestation is known to be present, an insecticide should be applied at planting. Wireworms are usually most damaging in bottom- lands or in poorly drained areas on upland soils. Low spots in the field often have the heaviest populations. The proportion of fields of corn affected by wire- worms in Illinois is small (less than 1 percent) and does not justify the widespread use of a soil insecticide on first-year corn after soybeans. A diazinon + lindane planter-box seed treatment may help deter the wire- worms from attacking the seed but will not protect the seedling. Checking for Wireworms A technique using baits has been developed for evaluating 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 candidates for bait stations. Since wireworm infestations are usually not uniform within a field, it will be necessary to place the bait stations randomly throughout the field. One bait station per acre is desirable. As a minimum, place 2 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 corn at each station. 2. Bury the bait about 4 inches deep. It is also desirable 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 corn 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 station, 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 treatment to areas where the concentration is heaviest. WHITE GRUBS Several species of economically important white grubs have 3-year life cycles. Peak years of damage usually 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 vege- tation, 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 injury visible aboveground are irregular emergence, reduced stands, and stunted or wilted plants. The damage is usually spotty throughout the field. There are no effective rescue treatments for white grubs after the damage 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, use a labeled soil insecticide. PLANTER-BOX SEED TREATMENTS Corn. Use a seed treatment in fields that do not receive a soil insecticide at planting time. A planter-box seed treatment with diazinon will protect germinating corn against attack by seedcorn beetles and maggots. A diazinon + lindane planter-box seed treatment protects seed from attack by seedcorn maggots, seedcorn beetles, and wireworms. Lorsban 50-SL is labeled as a slurry treatment on seed before planting to protect germinat- ing seed against injury by seedcorn maggots and beetles. NOTE: Excess dust from the seed treater may interfere with the electronic monitor in air planters. Some seed may have already been treated with a certain combination of insecticide and fungicide. Ad- dition of diazinon + lindane may cause planter units to gum up. Consult your seed or insecticide dealer to obtain specific information about seed treatment com- binations. Soybeans. Use a diazinon or diazinon + lindane 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. CALIBRATION FOR GRANULAR 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 insecticide bags have a list of suggested settings for the particular model of applicator. The settings are based on planting speed. The beginning settings are help- ful, but be sure to check your actual application rate under your own operating conditions. Follow these steps for calibrating the applicator: 1. Calibration of granular applicators for soil in- secticides is usually based on ounces of product needed per 1 ,000 feet of row. Consult the insecticide label or Table 3 for labeled rates for rootworm control. These rates are expressed in ounces per 1 ,000 feet of row and in pounds of product per acre. 2. Consult the label or manufacturer's recommen- dation 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 container 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 that weighs in ounces (e.g., a postal scale or a diet scale). 7. Compare the quantity (ounces) per bag against those given in Table 3. To obtain one pound of active ingredient per acre the following amounts of material should be collected: Formulation, percent Oz. collected per 1,000 ft. 10 12 15 8 20 6 8. Recalibrate if the difference in quantity applied during the calibration process is more than 10 percent over or under the rate suggested on the label. EUROPEAN CORN BORERS Corn 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. First-generation borers reduce yields by stalk-tunneling, which weakens the plant and destroys the tissue used to transport food within the plant. Corn that is planted early (the fields with the tallest corn) should be monitored closely from mid-June to early July for signs of whorl-feeding by corn borer larvae. The fields with the tallest corn in mid-June are the most attractive to moths laying eggs for the first generation. Control is warranted if 50 percent or more of the plants have fresh whorl-feeding and live borers are present. Seed production fields should be treated when 15 to 25 percent of the plants have whorl-feeding and larvae are present. Corn hybrids have varying degrees of tolerance or resistance to leaf-feeding by first-generation borers. Con- sider this trait when selecting varieties for 1985. Corn planted late is most attractive to moths laying eggs for the second generation. Yield losses caused by second-generation borers are a result of stalk breakage and ear drop, as well as physiological damage. Corn- borer entrance holes also provide avenues for stalk rot organisms. Monitor fields from mid-July to mid-August for egg masses or newly hatched larvae of the second brood. To assess the potential for second-generation corn borers, start checking for egg masses when moth flight is under way. Examine a minimum of 25 plants, selected at random throughout the entire field, and count the number of egg masses that are found on each plant. Although the moths usually lay their eggs on the two or three leaves above or below the developing ear, you should check all the leaves. One technique is to remove the leaves one by one, starting at the bottom of the plant, and carefully scan them for egg masses. The eggs, which are deposited in masses of 15 to 30, overlap like the scales of a fish. Calm nights favor egg deposition by the moths. The absence of hard, beating rains during moth emergence also increases the potential for infestations. Egg masses are flat and about half the size of your little fingernail. Newly deposited eggs are white, then turn pale yellow, and become darker just before hatch- ing. Eggs that are about to hatch have distinct black centers. These are the black heads of the larvae that are visible through the translucent eggshell. The eggs hatch in 3 to 7 days, depending on the temperature. The female moth hides in grass and weeds during the day. Noncrop areas that border cornfields may harbor large numbers of corn borer moths during the day. Check these areas for moths as you enter the field to determine the potential for corn borer infestation. Treatment is warranted when you find 1 egg mass for every two plants. Because peak egg laying generally occurs over a period of 2 to 4 weeks, it will be necessary to resample fields if egg masses are not present on half of the plants during the initial survey. If cumulative counts (taken 1 week apart) exceed 1 egg mass for every two plants, apply a treatment. For best results, treatment should be applied soon after egg hatch to kill the young larvae before they bore into the plant. The larvae begin tunneling into the stalks about 10 days after hatching. Because egg laying for the second generation extends over a 3- to 4-week period, timing of insecticide application should be pre- cise. Occasionally, two treatments may be necessary for satisfactory control. CORN LEAF APHIDS Corn leaf aphids are small, soft-bodied, greenish- blue plant lice about the size of a pinhead. They do not overwinter in Illinois. 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 rap- idly. Corn leaf aphids cause damage by sucking moisture and nutrients 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 pollination if aphid populations continue to cover the tassel and one or two of the upper leaves. REDUCED TILLAGE AND NO-TILL CORN INSECT PESTS Concern about insect problems should not keep growers from adopting conservation tillage practices. The soil-insect complex in corn, which is similar in many ways in conventional and reduced-tillage systems, can be readily controlled by applying soil insecticides at planting time. Outbreaks of insects feeding on foliage can usually be controlled with properly timed insecticide treatments. Close monitoring of fields to detect insect outbreaks is essential, regardless of the tillage system. Weather conditions and the type of crop rotations determine 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 pro- nounced where no-tillage is used in corn than where conventional or reduced-tillage systems are used. 10 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 practices provides a stable environment for pest survival and development. Pests occurring under these conditions include European corn borer, cutworms, army- worm, common stalk borer, wireworms, seedcorn maggots, billbugs, 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 broadleaf weeds are prevalent. Soil Insect Control Select a soil insecticide that will control the antici- pated soil insect pest. Consult Table 5 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 planting. To be most effective, the soil insecticide should be incorporated into the upper V2 inch of soil, and not just broadcast on the surface. Granules remain- ing on the soil surface are degraded by sunlight, resulting in erratic or poor control. NOTE: Before using Broot, Dyfonate, Mocap, or Thimet on no-till corn, be sure that soil moisture is low enough to ensure closing of the seed furrow to prevent the insecticide 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 corn 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 improve coverage and control. Instances of damage to corn by the common stalk borer have been greater in no-till corn 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 corn in fields previously infested with host weeds, the newly hatched stalk borer larvae move from the dead vegetation and attack newly emerging corn plants. Rescue treatments may give er- ratic control of common stalk borer because the chem- icals cannot reach the worms inside the stem. To reduce the potential of stalk borer damage in a subsequent season, it is essential to have good weed control within a field during August and September, when moths are laying eggs. FORAGE INSECTS Alfalfa weevils may cause moderate to severe damage to the first cutting of alfalfa in most areas of Illinois. 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 northern counties will occur on the stubble and new growth of the second cutting. Numbers of alfalfa weevils are regulated to a large extent by winter weather. During a cold, open winter the mortality rate is high in overwintering weevil pop- ulations; during mild winters the mortality rate is low. A parasitic wasp and a fungal disease organism that attack alfalfa weevil larvae sometimes regulate weevil numbers in the spring. Although the wasp and the fungus will be present in alfalfa fields in 1986, 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 ter- minals. As the larvae grow, they skeletonize the leaves, and damaged fields appear tattered. Growers in northern Illinois should look carefully for larval damage in 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 Pro- gram," to determine 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 is 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. 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. Damage first appears as a yellow, wedge-shaped area at the tip of the leaf and is more evident during dry weather. Many people confuse the damage with diseases or nutrient deficiency. Table 4. Economic Thresholds for Potato Leafhoppers on Alfalfa Alfalfa height (inches) Average number o\ leafhoppers per sweep of sweep net 0-3 3-6 6-12 12 or taller 0.2 0.5 1.0 1.5 11 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 also indicates that there may be a problem in the new growth. The economic threshold for leafhoppers varies with the height of the alfalfa (see Table 4). A treatment is justified when the number of leafhoppers exceeds the economic threshold. BEAN LEAF BEETLES Bean leaf beetles overwinter as adults under debris in fencerows, wooded areas, and other protected sites. The survival of the overwintering beetles depends on the winter weather. A mild winter increases the chances for a large population in the spring. In addition, if soybeans are planted early, the beetles will establish themselves early. The availability 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. The beetles may cause considerable leaf-feeding in- jury to double-cropped soybeans and late maturing soybean varieties. Insecticide treatments are recom- mended during the critical pod-set and pod-fill stages when defoliation exceeds 20 percent. The greatest con- cern, however, is caused by the beetles' pod-feeding damage, which leaves scars on many pods. These scars predispose the pods to fungal infections. A treatment is recommended when 5 to 10 percent of the pods are damaged. CHEMICAL INJURY TO SOYBEANS There have been instances of phytotoxicity to soy- beans when organic phosphate soil insecticides were used. The problems have occurred where growers started planting soybeans without first emptying the insecticide boxes. Organic phosphate soil insecticides applied in soybean fields treated with Sencor or Lexone may cause injury to a soybean crop, according to information on the labels. Table 5. Field Corn Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Armyworms *Furadan 15G *Ambush, *Pounce Dylox *Lannate, *Nudrin Lorsban 4E malathion *Penncap-M *Pydrin Sevin lb Band, furrow Apply as a planting-time treatment for early season control of army- worms in corn planted no-till in grass sod or small grains. 0.1-0.2 Broadcast At first migration, or when worms are eating leaves above ear level. V2-I Ambush, Lorsban 4E, Pounce, and Pydrin can also be applied as a V4-V2 preemergent treatment in no-till corn. 1 0.1-0.2 1 Billbug Chinch bug **Counter 15G Lorsban 15G Lorsban 4E lb l-2b 2 Band, furrow Band Broadcast-PPIc At planting. Lorsban 4E Lorsban 4E * Pydrin Sevin 1-1 '/2 Broadcast Apply as a postemergence rescue treatment with ground equipment when damage appears. lb Spray at base At start of migration from small grains. Use only ground equipment 0.1-0.2b of plant. and apply 20 to 40 gallons of finished spray per acre. 2b Common stalk borer Corn earworm *Ambush, *Pounce Lorsban 4E * Pydrin 0.1-0.2 Broadcast Furadan 15G applied at 2-3 lb. a. i. /acre at planting time may provide 1 - 1 !/2 early season suppression of common stalk borers. Apply postemergence 0.1 5-0. 2b sprays when damage first appears. See labels for specific instructions about effective control. *Lannate, *Nudrin Vz *Pydrin 0.1-0.2 Overall spray Justified only in seed corn fields. Treatments are rarely effective for or directed to- the control of earworms after worms enter ear tips. Ambush and ward ear zone Pounce have 24(c) labels for control of corn earworms in seed pro- duction fields. Corn leaf aphid Lorsban 4E malathion *Penncap-M l/2-l 1 '/2-'/4 On foliage Apply during late whorl to early tassel when 50% of plants have light to moderate infestations and plants are under drouth stress. 12 Table 5. Field Corn (continued) Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Corn rootworm beetles diazinon spray Imidan Lorsban 4E malathion *Penncap-M * Pounce *Pydrin Sevin Vt Vi '/2-I 1 '/2 0.1-0.2 0.1-0.2 1 Overall spray or directed toward To protect pollination, treat before 75% of plants have silked, if there are 5 or more beetles per plant, and if silk clipping is observed. ear zone Corn rootworm larvae Broot 15GX **Counter 15G ** Dyfonate 20G, 4E ** Furadan 15G *Furadan 4F Lorsban 15G ** Mocap 15G **Thimet 20G lb lb lb lb lb lb lb lb Band Band, furrow Band Band, furrow Band Band Band Band At planting. Counter 15G, Dyfonate 20G, Furadan 15G and 4F, Lorsban 15G and 4E, Mocap 15G, and Thimet 20G can also be applied at cultivation time. Cutworms *Ambush, *Pounce Lorsban 15G Lorsban 4E *Pydrin 0.1-0.2 lb 1-2 0.1-0.2 PREd Band at plant- ing Broadcast-PPP PREd Counter 15G, Dyfonate 20G, Furadan 15G, and Mocap 15G will control light to moderate infestations of cutworms. *Ambush, *Pounce Lorsban 4E *Pay-Off *Pydrin Sevin bait 0.1-0.2 Broadcast-PEe Apply as a postemergence rescue treatment when 3 percent or more 1-1 '/2 Broadcast-PEe of the plants are cut in the 2-leaf stage and there are 2 or more 0.04-0.08 Broadcast-PEc cutworms per 100 plants. At the 4-leaf stage, control is justified if 3 0.1-0.2 Broadcast-PEc percent or more of the plants are cut and there are 4 or more worms 1-2 Broadcast-PEe per 100 plants. European corn *Ambush, * Pounce 0.1-0.2 borer, first diazinon 14G 1 generation Dipel 10G See label **Dyfonate 20G 1 **Furadan 15G, 4F 1 Lorsban 15G 1 *Penncap-M 1 On upper '/s When 50% or more of the plants have fresh whorl-feeding and live of plant and borers are present. Sprays are most effective when directed over the into whorl row, rather than broadcast. European corn borer, second generation diazinon 14G ** Dyfonate 20G **Furadan 15G, 4F Lorsban 15G *Penncap-M On foliage Apply at first hatch when half of the plants have egg masses, or when cumulative counts, made one week apart, exceed 1 egg mass for every 2 plants. Fall armyworm Dylox *Lannate, *Nudrin Lorsban 4E 1 Vt 1 On foliage Treat when 35% of plants have whorl damage and if worms are present. Ground sprays directed over the row are more effective than broadcast sprays. Treatments to control worms in ear tips are not effective. Flea beetles *Ambush diazinon spray Lorsban 4E *Penncap-M Sevin 0.1-0.2 i/2b lb l/,b Over row When leaves on seedling plants are severely damaged and some plants as spray are being killed. Grasshoppers Cygon diazinon spray *Furadan 4F Lorsban 4E malathion *Penncap-M *Pydrin >/2 Vi Vs-V* V*-Vz 1 v*-v* 0.1-0.2 On foliage As needed. The higher rates are suggested for control of adult grasshoppers. Sevin '/2-l'/2 Hop vine borer None labeled Postemergence sprays of Ambush, Pounce, Pydrin, or Lorsban ma) give some control if applied when damage first appears. Japanese beetle Sevin 1 On foliage During the silking period to protect pollination if less than 7591 >>t plants are silked and there are 3 or more beetles per ear. 13 Table 5. Field Corn (continued) Insect Insecticidea Pounds of active ingredient per acre Placement Timing of application, comments Picnic, sap beetles diazinon spray *Lannate malathion Sevin 1 1 1 On foliage Justified only in seed corn fields when beetles are feeding on ear tips. Seedcorn beetles **Counter 15G **Dyfonate 20G Lorsban 15G **Thimet 20G lb lb lb lb Band, furrow Band Furrow Band At planting. diazinon diazinon + lindane Lorsban 50-SL See label See label See label On seed On seed On seed Use formulations that are prepared as seed treaters. Seedcorn maggots **Counter 15G **Dyfonate 20G **Furadan 15G Lorsban 15G **Thimet 20G lb lb lb lb lb Band, furrow Band Furrow Furrow Band At planting. diazinon diazinon + lindane Lorsban 50-SL See label On seed Use formulations that are prepared as seed treaters. Seed treatments See label On seed should be considered for fields that do not receive a soil insecticide See label On seed at planting. Sod webworm Lorsban 4E Vi-l Broadcast At time of initial attack. Southwestern diazinon 14G 1-2 corn borer **Dyfonate 20G 1 **Furadan 15G, 4F 1 Lorsban 15G, 4E 1 *Penncap-M 1 *Pydrin 0.1-0.2 On foliage Direct granules over row. Apply when 25% of the plants have egg masses or larvae on leaves. Early-planted corn usually escapes damage. Sprays are most effective when directed over the row, rather than broadcast. Spider mites Cygon V2 diazinon spray Vi **Di-Syston 15G 1 ethion spray 1 **Thimet 20G 1 Trithion 1 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. Symphylans **Counter 15G *Dyfonate 4E Lorsban 15G Lorsban 4E **Mocap lb 2 1-1 '/2b 1-2 It- Band, furrow Broadcast-PPIc Band Broadcast-PPIc Band At planting. Thr malathion 1 On foliage When severe wilting and yellowing of leaves are noticed. White grubs **Counter 15G Lorsban 15G Lorsban 4E **Thimet 20G lb l-2b 2 lb Band, furrow Furrow Broadcast-PPP Band At planting. Wireworms **Counter 15G **Furadan 15G Lorsban 15G Lorsban 4E **Mocap 15G **Thimet 20G lb lb 2b 2 lb lb Band, furrow Band, furrow Band, furrow Broadcast-PPIc Band Band At planting. Woollybear caterpillars None labeled Silk clipping caused by caterpillars does not generally warrant control. * Use restricted to certified applicators only. ** Granular formulations of Counter, Di-Syston, Dyfonate, Furadan, Mocap, and Thimet released for shipment by the manufacturer after September 1, 1985, are restricted. a See Table 13 for insecticide restrictions. b Based on 40-inch row spacing. Increase rates for narrow rows. c PPI Pre-plant incorporated. d PRE Preemergent application. e PE Postemergent application. 14 Table 6. Soybeans Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Bean leaf beetle *Ambush, *Pounce Cygon Lorsban 4E Orthene *Penncap-M *Pydrin Sevin 0.05-0.1 '/2 Vi V* V* 0.1 1 On foliage Before bloom: when defoliation reaches 30%, at least 1 cotyledon per foot of row is destroyed, and there are 5 or more beetles per foot of row. Bloom to pod fill: when defoliation reaches 20% and there are 16 or more beetles per foot of row. Seed maturation: when 5 to 10% of the pods are damaged, the leaves are green, and there are 10 or more beetles per foot of row. Blister beetles Cutworms Sevin 1 On foliage When defoliation reaches 30% before bloom and 20% between bloom and pod fill. On foliage Damage occurs when larvae feed on pods. Apply control if populations exceed 1 per foot of row. Corn earworm *Ambush, * Pounce 0.1 *Lannate, *Nudrin >/2 Orthene 1 *Pydrin 0.1-0.2 Sevin bait Lorsban 4E *Pydrin 1-2 1 0.1-0.2 Broadcast Broadcast Broadcast Scout as plants are emerging. Treat if 20% of plants are cut and stand has gaps of one foot or more and cutworms are present. Grasshoppers Cygon *Furadan 4F Lorsban 4E Orthene *Penncap-M *Pydrin Sevin '/8-'/4 '/4-'/2 %M '/4-3/4 0.1-0.2 Vt-V/i On foliage When migration into fields begins and defoliation or pod feeding reaches economic levels. When defoliation reaches 30% before bloom and 20% between bloom and pod fill. The higher rates are suggested for control of adult grasshoppers. Green clover- worm * Ambush, *Pounce Dipel, Thuricide, Bactur, SOK (Ba- cillus thuringiensis) Lorsban 4E Orthene *Penncap-M *Pydrin Sevin 0.05-0.1 See label Vi Vt 0.05-0.1 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 20% defoliation to justify treatment. Japanese beetle *Penncap-M * Pounce *Pydrin Sevin 3/4-l 0.05-0.1 0.1-0.2 1 On foliage When defoliation reaches 20% during bloom and pod fill. Loopers * Ambush, *Pounce Orthene *Pydrin Thuricide, Dipel, Bactur, SOK (Ba- cillus thuringiensis) 0.05-0.1 On foliage '/2-1 0.1-0.2 See label When defoliation reaches 30% before bloom and 20% between bloom and pod fill. Mexican bean beetle * Ambush, *Pounce Cygon *Furadan 4F Lorsban 4E Orthene *Penncap-M *Pydrin Sevin 0.05-0.1 Vi Vi Yt '/2 Vt 0.05-0.1 1 On foliage When defoliation reaches 30% before bloom and 20% between bloom and pod fill. Potato leafhopper *Ambush, *Pounce Cygon *Penncap-M *Pydrin Sevin 0.05-0.1 Vi Vs 0.05-0.1 1 On foliage When leafhoppers are numerous and the edges of the leaves appear burned. 15 Table 6. Soybeans (continued) Insect Insecticide* Pounds of active ingredient per acre Placement Timing of application, comments Saltmarsh caterpillar ♦Ambush 0.05-0.1 *Lannate, *Nudrin V2 Lorsban 4E V2 *Pvdrin 0.05-0.1 On foliage When defoliation reaches 30% before bloom and 20% between bloom and pod fill. Seedcorn maggot diazinon diazinon + lindane See label See label On seed On seed At planting time. Use formulations that are prepared as seed treaters. Spider mites Cygon Lorsban 4E Vi V2 *Penncap-M V2 Trithion '/2-3/4 Stink bugs Lorsban 4E 1 Orthene y*-\ *Penncap-M i/2-% *Pydrin 0.1-0.2 Sevin 1-11/2 On foliage As needed on field margins or entire field. On foliage When adult bugs or large nymphs reach 1 per foot of row during pod fill. Thistle caterpillar Sevin 2 On foliage When defoliation reaches 30% before bloom and 20% between bloom and pod fill. Thrips *Penncap-M Sevin '/2-3/4 1 On foliage If seedlings are being seriously damaged and some plants are being killed. Webworms Sevin 1 On foliage When defoliation reaches 30% before bloom and 20% between bloom and pod fill. Whitefly None labeled High infestations are occasionally present on double-crop soybeans, but are rarely economic. Woollybear caterpillars Lorsban 4E * Pounce *Pydrin '/2-1 0.1 0.1 When defoliation reaches 30% before bloom and 20% between bloom and pod fill. Sprays of Ambush or Penncap-M may also be effective. * Use restricted to certified applicators only. a See Table 13 for insecticide restrictions. Spraying blossoming soybeans can be extremely hazardous to bees. Coordinate with local beekeepers before applying sprays. Beekeepers' names and colony locations may be obtained from your County Extension Office. Table 7. Alfalfa and Clover To avoid injury to bees, do not spray alfalfa during bloom or if weeds are blooming. Insect Insecticideab Pounds of active ingredient per acre Placement Timing of application, comments Alfalfa weevil (spring treat- ment for larvae) *Furadan 4F Imidan Lorsban 4EC malathion + methoxychlor * Penncap-M *Supracide V4-V2 1 1 2 qt. per acre '/2 Vt 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 immediately. Do not apply sprays during bloom. Instead, cut and remove the hay. Two treatments may be necessary on first cutting. Watch regrowth for signs of damage, and treat if feeding damage is apparent. Alfalfa weevil adults *Furadan 4F Imidan Lorsban 4EC * Penncap-M l/2-l 1 1 % As a stubble spray. 16 Table 7. Alfalfa and Clover (continued) Insect Insecticide3,6 Pounds of active ingredient per acre Placement Timing of application, comments Aphids Cygon *Furadan 4F *Lannate, *Nudrin Lorsban 4EC malathion *Penncap-M V* V* V2 1 On foliage When aphids average 100 or more per sweep and lady beetle larvae and adults, parasites, and diseases are not abundant. *Supracide V2 Avoid treatments when plants are blooming. Blister beetles Sevin 1 On foliage Although blister beetles rarely cause economic damage to alfalfa, their presence in hay could injure horses if the horses ingest the beetles. Clover leaf weevil malathion 1 On foliage When larvae are numerous (5 or more per crown) and leaf feeding is noticeable, usually in early to mid-April. Cutworms Dylox Lorsban 4EC Sevin 1/2-1 1 l'/2 On foliage As needed on regrowth of second cutting. Fall armyworm Dylox *Lannate, *Nudrin Lorsban 4EC 1 Vt 1 On foliage Usually in late summer or early fall on new seedlings or established stands. Grasshoppers Cygon diazinon '/2 *Furadan 4F '/8->/4 Lorsban 4EC lA-lA *Penncap-M V*-V4 Sevin L-1V2 Leafhoppers Cygon *Furadan 4F Lorsban 4EC '/2-1 * Pen neap- M '/2-3/4 Sevin 1 *Supracide Yt On foliage When grasshoppers are small and before damage is severe. The higher rates are suggested for control of adult grasshoppers. Avoid treatments when plants are blooming. On foliage Treatment is justified at these combinations of alfalfa height and leafhopper numbers: Alfalfa height Leafhoppers (inches) per sweep 0-3 0.2 3-6 0.5 6-12 1.0 12 or taller 1.5 Avoid treatments when plants are blooming. Plant bugs Cygon Dylox *Furadan 4F Lorsban 4EC *Penncap-M Sevin V4-V2 On foliage When tip damage is obvious and nymphs and adults are numerous. 1 1 '/2-1 [/i-3A 1 Avoid treatments when plants are blooming. Spittlebug Imidan Lorsban 4EC malathion + methoxychlor malathion *Penncap-M 1 '/2-l 2 qt. per acre 1 '/2-3/4 On foliage When spittle masses are found and nymphs average more than 1 per stem. Avoid treatments when plants are blooming. Webworms Dylox malathion + methoxychlor Sevin 1 2 qt. per acre 1 On foliage If damage appears. * Use restricted to certified applicators only. a See Table 13 for insecticide restrictions. b 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. c Young, tender, rapidly growing alfalfa may show some phytotoxic symptoms when treated with Lorsban 4E. Spraying blossoming alfalfa can be extremely hazardous to bees. Coordinate with local beekeepers before applying sprays. Beekeepers' names and colony locations may be obtained from your County Extension Office. 17 Table 8. Grain Sorghum Pounds of active ingredient Insect Insecticide3 pe r acre Placement Timing of application, comments Chinch bug Lorsban 4Eb Sevin 1 2 At plant base Use only ground equipment and apply 20 to 40 gallons of finished spray per acre. Corn earworm Tannate, *Nudrin Sevin '/2 1-2 Over row When there is an average of 2 worms per head. Corn leaf aphid Cygon Lorsban 4Eb malathion l Over row Corn leaf aphids rarely cause economic damage unless populations are heavy and drouth conditions exist. Cutworms Lorsban 15G Lorsban 4Eb lc Band 1 Broadcast At planting. When seedling plants are being cut. Fall armvworm *Lannate, *Nudrin !/2 Lorsban 4Eb 1 Sevin 1 Vi Over row When there is an average of 2 worms per head. Leaf feeding or whorl damage is seldom economic. Grasshoppers Cygon Lorsban 4Eb Sevin '/4-!/2 '/2-l'/2 Over row As needed. The higher rates are suggested for control of adult grasshoppers. Greenbug Cygon diazinon spray Lorsban 4Eb malathion lA-Vt lA V4-V4 1 Over row When greenbug damage is sufficient to cause death of more than 2 normal-sized leaves before the hard-dough stage. CAUTION: Some sorghum varieties are sensitive to organophosphate insecticides. Counter 15G Furadan 15G Thimet 20G 1-2C lc lc Band Band, furrow Band At planting. Sorghum midge diazinon spray *Lannate, *Nudrin Lorsban 4Eb V* V* Over row Apply during bloom when 50% of heads have begun to bloom and there are 1 or more midge adults (flies) per head. White grubs *Counter 1-2C Band At planting. Wireworms *Counter 1-2C Band At planting. Webworms *Lannate, *Nudrin V2 Lorsban 4Eb 1 Sevin 1-2 Over row When 5 or more larvae per head are found. Yellow sugar- cane aphid Cygon Lorsban 4Eb 14 V4-V2 Over row Treatment should be applied at first sign of damage to seedling sorghum; 5 to 10 aphids per leaf. * Use restricted to certified applicators only. a See Table 13 for insecticide restrictions. b To avoid phytotoxicity, do not treat plants that are under extreme heat and drouth stress. c Based on 40-inch row spacing. Increase rates for narrow rows. Table 9. Small Grains (Barley, Oats, Rye, Wheat) Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Army worm Dylox l/s-\ *Lannate, *Nudrin !4-/4 *Penncap-M V2-V4 Sevin 1 On foliage When there are 6 or more armyworms per linear foot of row and before extensive head cutting occurs. Do not use Dylox or Penncap-M on rye. Cereal leaf beetle *Furadan 4F *Lannate malathion Sevin Vi V4-V2 1 1 On foliage When there are one or more small larvae per stem or flag leaf. Apply Furadan before heads emerge from the boot. Fall armyworm Dylox Sevin 1 On foliage During fall when damage to new growth is apparent. Do not use 1-1 14 Dylox on rye. 18 Table 9. Small Grains (Barley, Oats, Rye, Wheat) (continued) Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Grasshoppers Cygon *Furadan 4F malathion *Penncap-M Sevin Vs l '/4-»/4 V2-V/2 On foliage During fall when damage is apparent, treat field borders and noncrop areas to stop migration. The higher rates are suggested for control of adult grasshoppers. Do not apply Penncap-M to rye. Greenbug, English grain aphid, oat bird- cherry aphid Cygon malathion * Penncap-M ■/4-y8 1 On foliage Aphids damage plants indirectly by transmitting disease. Once yellow- ing is noticeable, it is usually too late to treat. Use Cygon on wheat only. Do not apply Penncap-M to rye. Variegated cutworm Dylox l/2-l As needed. Do not use Dylox on rye. Wheat stem maggot None No chemical control. Damage shows as white heads when field is stil green. * Use restricted to certified applicators only. 3 See Table 13 for insecticide restrictions. Table 10. Grass Pasture Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Armyworms Dylox malathion * Penncap-M Sevin 1 VA >/2-3/4 1 On foliage As needed. Sevin and Dylox may be applied without removal of grazing livestock. Do not apply when weeds are blooming. Grasshoppers diazinon spray malathion * Penncap-M Sevin '/2 1 !/2-l'/2 On foliage As needed. The higher rates are suggested for control of adult grasshoppers. Do not apply when weeds are blooming. * Use restricted to certified applicators only. a See Table 13 for insecticide restrictions. Table 11. Noncrop Areas Insect Insecticide3 Pounds of active ingredient per acre Placement Timing of application, comments Grasshoppers diazinon malathion * Penncap-M *Pydrin !/2 On foliage When grasshopper nymphs average 15 to 20 per square vard along 1 roadsides and fence rows. The higher rates are suggested for control '/4-3/4 of adult grasshoppers. Do not spray areas adjacent to water or where 0.05-0.1 runoff is likely to occur. Applv treatments while hoppers are small Sevin V2-W2 and before they migrate into row crops. To avoid injury to bees, do not apply sprays to noncrop areas if weeds are blooming. * Use restricted to certified applicators only. 3 See Table 13 for insecticide restrictions. 19 Table 12. Sunflowers Grasshoppers *Furadan 4F Lorsban 4E *P\ drin Sevin Pounds of active ingredient Insect Insecticide3 per acre Placement Timing of application, comments Armyworm Sevin 1 Vl-2 Over row When defoliation reaches 25%. Cutworms Sevin Lorsban 4E l'/a 1-1V4 Over row When 10% of the seedlings are damaged. Fall armyworm Sevin 1 l/j-2 Over row When defoliation reaches 25%. Vt-Vi 0.1-0.2 1-1 Vi Over row When defoliation reaches 25%. Stem w-eevil *Furadan 4F Lorsban 4E Sevin *Supracide '/2-3/4 1-2 Vi Over row When there are 2 or more beetles per plant. Sunflower beetle *Furadan 4F Lorsban 4E *Pydrin Sevin Vi-1/* '/2-S/4 0.05-0.1 1-2 Over row When defoliation reaches 25%. Sunflower moth larvae *Furadan 4F Lorsban 4E *Pydrin *Supracide Vi Vi-% 0.1-0.2 Vi Over row Apply nrst treatment when a field has reached 20 to 25% bloom and moths are present. * Use restricted to certified applicators only. a See Table 13 for insecticide restrictions. Spraying blossoming sunflowers can be extremely hazardous to bees. Coordinate with local beekeepers before applying sprays. Beekeepers' names and colony locations may be obtained from your County Extension Office. Table 13. Limitations in Days Between Application of the Insecticide and Harvest of Crop and Restrictions on Use of Insecticides for Field Crop Insect Control (These are only guidelines — read the label for more detailed information) (Blanks denote that the product may not be labeled or suggested for that specific use in Illinois) Worker re-entry time (days)3 Field corn Grain Ensilage Grain Sorghum Forage crops Alfalfa Clover Pasture * Ambush (permethrin)ab Broot (trimethacarb) *Counter (terbufos) Cygon (dimethoate)b Diazinon Dipel {Bacillus thuringiensis) A 90 B 14,E B B A 90 30,C 14,E 10 B D 28,E 7 10,F 7 *Di-Syston (disulfoton)ab *Dyfonate (fonofos)b Dylox (trichlorfon) Ethion *Furadan (carbofuran)ab 1 14c 40 30 G 50, H 30,I,J 40 30 G 50, H 30.IJ 75 0,G K 0, Imidan (phosmet) **Lannate (methomyl)ab Lorsban (chlorpyrifos) Malathion Methoxvchlor 14 B 35, L 5 14 3 14, L 5 14 60, M 7 7,F 0 21, N 0 7 *Mocap (ethoprop) **Nudrin (methomyl)ab * Pay-Off (flucythrinate) *Penncap-M (microencapsulated methyl parathion)a,b * Pounce (permethrin)a,b *Pydrin (fenvalerate)ab B B 28,P 12 A 21,Q B 3 28, P 12 A 21,Q 14 0 15 15 Sevin (carbaryl) *Supracide (methidathion)ab *Thimet (phorate) Trithion (carbophenothion)ab 0 30.S B 0 30,S 21,T 21 3 10, R 20 Table 13. Limitations (continued) Worker re-entry time (days)a Barley Oats Rye Wheat Soybeans Sunflowers *Ambush (permethrin)ab 60, L Cygon (dimethoate)b 60 21 Dipel, Thuricide, Bactur, SOK. 0 (Bacillus thuringiensis) Dylox (trichlorfon) 21 21 21 *Furadan (carbofuran)ab 14c V V V 21,W 28,X **Lannate (methomyl)ab 7 7 7 7 14 Lorsban (chlorpyrifos) 28,Y 42, Z Malathion 7 7 7 7 0 **Nudrin (methomyl)ab 7 7 7 7 14 Orthene (acephate) 14, AA *Penncap-M (microencapsulated 15 15 15 20,BB methyl parathion)a,b *Pounce (permethrin)ab 60.U *Pydrin (fenvalerate)ab 21.CC 28.CC Sevin (carbaryl) 21, DD 0 60 *Supracide (methidathion)ab 2 50.AA Trithion (carbophenothion)ab 7,AA Read the label for more detailed information. A. Apply prior to ear formation. Ear formation occurs when polli- nation is completed as evidenced by initiation of brown silk. B. No specific restriction when used as recommended. C. Only 1 postemergence incorporated treatment or 1 cultivation- time treatment may be used in addition to treatment at planting time. D. Only one application per year may be used. E. Make no more than 3 applications per year. Do not apply to sorghum after heading. F. Apply only once per cutting; do not apply during bloom. G. Three applications may be made per season on corn, and 3 applications may be made per cutting of alfalfa or grasses. Can be applied up to harvest. H. Do not make more than 1 application after ear formation. Do not feed treated foliage to livestock. I. Do not make a foliar application if Furadan 15G was applied at more than 8 ounces per 1,000 linear feet of row (6.7 pounds per acre with 40-inch row spacing) at planting. Do not make more than 2 foliar applications of Furadan 15G per season. J. Do not make more than 2 applications of Furadan 4F per season at the l'/2-2 pint use rate. Do not make more than 4 applications per season at the 1 pint use rate. Do not apply on seed corn less than 14 days prior to detasseling or rogueing. If prolonged, intimate contact will result, do not reenter treated field within 14 days of application without wearing proper clothing. K. Make no more than 2 applications per season. Do not apply more than once per cutting. Do not use more than 1 pint per acre in the second application. Apply only to fields planted to pure stands of alfalfa. When using no more than lA pound per acre, allow 7 days between application and harvest. When using Vt to V2 pound per acre, allow 14 days between application and harvest. When using V2 to 1 pound per acre, allow 28 days between application and harvest. Do not move bees to alfalfa fields within 7 days of application. L. For soil insect control, do not exceed the equivalent of 16 ounces of Lorsban 15G per 1,000 feet of row or 13.5 pounds of Lorsban 15G per acre per crop season. For foliar insect control, do not exceed the equivalent of 16 ounces of Lorsban 15G per 1,000 feet of row or 13 pounds of Lorsban 15G per acre per crop season. Do not apply more than a total of 15 pints of Lorsban 4E per acre per season. Do not allow livestock to graze in treated areas nor harvest treated corn silage as feed for meat or dairy animals within 14 days after last treatment. Do not feed treated corn fodder to meat or dairy animals within 35 days after last treatment. M. The treated crop is not to be used for forage, fodder, hay, or silage within 30 days after application of 1 pint of Lorsban 4E per acre or within 60 days after application of rates above 1 pint per acre. Do not treat sweet varieties of sorghum. Do not apply more than 3 pints of Lorsban 4E per acre per season. N. Do not apply more than once per cutting. Do not cut or graze treated alfalfa within 14 days after application of 1 pint of Lorsban 4E per acre, nor within 21 days after application of rates above 1 pint per acre. Do not make more than 4 applications per year. P. Do not apply by air. Do not make more than 2 applications per season. Q. Do not exceed 1.0 pound of active ingredient per acre per season. R. Make no more than 1 foliage and 1 stubble application per alfalfa cutting. S. Do not make more than one application over the plant. T Do not make more than one application per season. U. Do not graze or feed soybean forage or hay. Do not make more than 2 applications per season. V. Apply before heads emerge from boot. Do not make more than 2 applications per season. Do not feed treated forage to livestock. 21 Table 13. Limitations (continued) W. Do not use Furadan 4F as a foliar application if Furadan 10G, Furadan 15G, Furadan 4F was applied to soybeans at planting time. Do not make more than 2 foliar applications per season. Do not graze or feed foliar-treated forage to livestock or cut for silage or hay. X. No more than 4 applications per season. Y. Do not apply more than 6 pints of Lorsban 4E per acre or 3 pounds of chlorpyrifos (active ingredient) per acre per season. Do not apply last 2 treatments closer than 14 days apart. Do not allow livestock to graze in treated areas nor otherwise feed treated soybean forage to meat or dairy animals within 14 days after application. Do not feed straw from treated soybeans to meat or dairy animals within 28 days after application. On determinate soybeans do not apply more than one application after pod set. Z. Do not apply more than 9 pints of Lorsban 4E per acre per season. Do not allow livestock to graze in treated areas. AA. Do not graze or feed treated crop to livestock. BB. Do not make more than 2 applications per season. CC. Do not feed or graze livestock on treated plants. Do not exceed 0.8 pound active ingredient per acre per season. DD. Do not make more than 2 applications after grain heads emerge from boot. * Use restricted to certified applicators only. ** Liquid formulations are restricted. a Workers should be warned in advance of treatments. Workers may not enter fields treated with the insecticides without wearing protec- tive 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. Protective clothing includes a hat, long-sleeved shirt, full length pants, and shoes and socks. b Sprays to be applied only by experienced operators wearing proper protective clothing. c Do not apply Furadan 4F on seed corn less than 14 days prior to detasseling or rogueing. If prolonged intimate contact will result, do not reenter field treated with Furadan 4F within 1 4 days of application without wearing proper protective clothing. Table 14. Relative Toxicities of Commonly Used Agricultural Insecticides Toxicity to mammals3 Toxic ity to Acute Acute Trade name Chemical name oral dermal Birds Fish Bees *Ambush permethrin low low low very high high Broot trimethacarb moderate low *Counter terbufos high high high very high Cygon dimethoate moderate moderate moderate very low high Diazinon diazinon moderate moderate high high high Dipel, Bactur, Topside, Bacillus thuringiensis very low very low very low very low very low Thuricide, ! >OK *Di-Syston disulfoton high high moderate moderate *Dyfonate fonofos high moderate moderate Dylox trichlorfon low low low very low low Ethion ethion high high low very low *Furadan carbofuran high moderate moderate moderate high Imidan phosmet moderate low low high **Lannate, ** = Nudrin methomyl high moderate low high Lorsban chlorpyrifos moderate moderate moderate very high high Malathion malathion low low low moderate high Methoxychlor methoxychlor low low very low very high low * Methyl parat hion methyl parathion high high moderate very low high *Mocap ethoprop moderate high moderate moderate Orthene acephate moderate moderate moderate low high *Pay-Off flucythrinate moderate low low very high high *Penncap-M microencapsulated methyl parathion moderate low moderate very low high * Pounce permethrin low low low very high high *Pydrin fenvalerate moderate low low very high very high Sevin carbaryl low low very low very low high *Supracide methidathion high moderate moderate high high *Thimet phorate high high moderate very high moderate Trithion carbophenothion high high high very high moderate * Use restricted to certified applicators only. ** Liquid formulations are restricted. a Relative toxicities based on acute oral and acute dermal LD50 values of technical insecticide. Toxicities of formulated materials vary. Always read the label before applying insecticides. 22 NOTES 23 UNIVERSITY OF ILLINOIS-URBANA Q.630.7IL6C C001 CIRCULAR URBANA, ILL. 899 REV 1985 3 0112 019532255 Prepared by Kevin L. Steffey, Donald E. Kuhlman, and Stephen P. Briggs, Extension Entomologists. 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. 12M— 10-85— 62690— Ct