Managing Soybean Insects

Many insects feed on soybeans and can threaten yield and/or quality. However, the frequency and severity of pest damage vary considerably between production areas--even within and between fields-- and from season to season. (In Texas, the Gulf Coast and Lower Rio Grande Valley counties are most likely to experience economic losses.) Therefore, it is important to inspect plants regularly and base control decisions on established economic thresholds or action levels.

The term integrated pest management (IPM) applies to a philosophy used in the design of insect, mite, dis-ease and weed control programs. IPM encourages the use of the most ecologically sound combination of effective pest suppression techniques. The IPM concept assumes that pests can be tolerated to some degree unless they cause economic loss. The first line of defense against them is prevention through the use of good agronomic practices or cultural methods that discourage pest population development. Control measures are implemented only when pest populations reach levels at which crop damage could result in losses greater than the cost of the treatment. This is called the economic threshold level or action level. Regular field scouting helps determine if and when that level is reached. Precise timing and execution of each production operation is essential. In short, IPM strives to optimize rather than maximize pest control efforts.

The economic thresholds or action levels presented in this publication should be used only as rules of thumb. Several factors affect the level of damage soybean plants can tolerate before the cost of a control tactic (such as the use of an insecticide) becomes profitable. These factors include the anticipated market value of the crop, anticipated yield, and the cost of the treatment. In general, when the market value of soybeans is high and/or the cost of control is low, economic threshold levels may actually decrease (fewer pests or pest damage can be tolerated). Threshold levels presented here may also change with the growing season, the presence of different pests, the type of damage, plant growth stage, and general plant vigor.

Some soybean varieties suffer more damage from certain pests (particularly caterpillars) than others. Other varieties are resistant to or tolerant of several of the major defoliating pests. Data on the yield potential for various soybean varieties in different areas of the state are available from your county Extension agent.

The Early Soybean Production System (ESPS) is a relatively new and popular method of growing soybeans in Texas. The ESPS, as practiced on the Upper Gulf Coast and in northeast Texas, relies on planting early-maturing soybeans (Maturity Groups IV and V) in April and harvesting in September. In the conventional system, later maturing soybeans (Maturity Groups VI, VII and VIII) are planted in May and June and harvested in October and November. Generally, soil moisture is lowest on the Gulf Coast and in northeast Texas in July and August when conventionally grown soybeans are in the crucial pod-fill stage of development. ESPS soybeans are usually beyond the pod-fill stage at this time. Adequate soil moisture allows ESPS soybeans to fill properly. Insect damage also is affected by plant maturity. For instance, defoliating caterpillars usually attack conventionally grown soybeans from late August to mid- September when ESPS soybeans are close to maturity and unattractive to insects. ESPS soybeans usually avoid defoliator damage, but are often subject to stink bug infestations earlier in the season, beginning at bloom. For more information on the ESPS, obtain the Early Soybean Production System Handbook from your county Extension agent.

Insect populations in soybean fields can change rapidly. Growers should check fields at least once and preferably twice a week to determine the species present, the pest density, and the amount of damage. Plant damage estimates are also useful in making management decisions.

Ground cloth method: This technique is primarily used to survey for stink bugs and caterpillars, but it is also useful for determining numbers of other species before and after pesticide applications. This method uses an off-white cloth measuring 36 x 42 inches. Staple a thin strip of wood, approximately 1 inch wide, to each short side of the cloth. Select a random site in the field and unroll the cloth from one row over to the next row. Mark off 18 inches on each row bordering the cloth and vigorously shake all the plants within that area. Two 1.5-row-foot sections (3 feet total) will be sampled simultaneously for insects. Count the number of insects that fall on the cloth. Repeat the process in at least ten locations in the field (30 feet of row sampled) and total the counts to get the number of each species per 30 row feet. If the results show that populations are close to threshold levels, or if the field is very large, sample more areas to increase confidence in the results. This method is not useful in drilled or broadcast-planted soybean fields. When the soil is wet another method may be more convenient.

Vertical beat sheet method: The vertical beat sheet is another method of sampling insect populations. This device is constructed of galvanized metal flashing, or similarly stiff material, 36 inches wide and crimped to provide a beating surface 34 inches tall and a collecting trough 4 inches wide. The trough is positioned at the base of row-planted soybean plants and arthropods are removed along 36 inches of row by shaking and beating the foliage against the vertically positioned surface. Dislodged arthropods slide into the trough where they can be counted in the field or poured into a container to be counted elsewhere. This method does not require kneeling down between the rows, and can be used to sample weedy fields, fields with standing water in the rows, and narrow-row or drill-planted soybean fields. Economic threshold levels developed for this sampling method are for rowplanted soybeans only and should not be used if row spacing is less than 30 inches.

Sweep net method: A standard 15-inch-diameter sweep net is often used for sampling insects on soybeans. Make ten consecutive (180-degree) sweeps while walking through the field, swinging the net from side to side across the row with each step. Then identify and count insects as they are removed from the net. Repeat the sampling procedure in at least ten random sites and total the counts of each species per ten sweeps to determine the number of insects per 100 sweeps. Increasing the number of samples taken from a field increases the accuracy of the population estimates. If the population estimates are close to threshold levels, or if the field is large, sample more areas to increase the accuracy of the results. Economic threshold levels developed for this sampling method are for row-planted soybeans only and should not be used if row spacing is less than 30 inches. The sweep net, however, is one of the few methods of sampling arthropods in drill- or broadcast-planted soybean fields.

Plant damage: Insects damage soybean plants in four ways. Soil insects can feed on germinating seedlings or roots, causing the plants to lose vigor, wilt or die. Above ground, stems can be damaged by tunneling larvae or girdled by the threecornered alfalfa hopper. Foliage can be damaged by chewing caterpillars and beetles, or by the feeding of mites, aphids and thrips. Finally, pods can be hollowed out by corn earworms and seed deformed and discolored by stink bug sucking damage. Estimating the level of insect damage is essential in determining the need for control measures.

Insects that feed on seedlings are important only if stands are damaged to the extent that yields are reduced. Six to eight healthy seedlings per row foot are sufficient for optimum yields. Uniform loss of seedlings is not as detrimental as the loss of all seedlings in portions of a row.

Threecornered alfalfa hoppers girdle the main stems of soybean plants. This damage first appears as slight indentations and later as swellings encircling the entire main stem. Randomly selected row-foot sections, at several locations in the field, should be examined for fresh damage early in the season (3- to 10-inch plants).

Foliage loss from the feeding of caterpillars and beetles is estimated visually. Examine randomly picked individual leaflets and estimate the percent leaf surface missing from each. Select an equal number of leaves from all levels of the plant canopy. Add these estimates together and divide by the total number of leaflets examined to determine the percent defoliation for the different areas of the sampled field. Research has shown that slight leaf-feeding injury may actually increase the yield of late maturity group soybeans. Beyond an initial 10 percent leaf surface loss, however, every additional 10 percent loss can decrease yield by 2 bushels per acre. Yield loss from defoliation depends on the soybean growth stage.

Pod damage is not sampled directly. Insects that cause pod damage are sampled using sweep net or ground cloth techniques.

From seed germination to harvest, a soybean crop is under constant attack from a variety of insects. Soybean plants can compensate for substantial levels of insect injury, and yield can even improve with low levels of injury. Losses depend greatly upon the stage of plant growth, so pest economic thresholds vary with the stage of plant development.

Soybean growth stages are designated by the letter V for vegetative or R for reproductive. There are two types of stem growth and flowering in soybeans. In the indeterminate stem type, grown mainly in the northern U.S., the terminal bud continues vegetative growth during most of the season. The plant develops a sparse but even distribution of pods on all branches. In the determinate stem type, grown mainly in the southern U.S., the terminal bud stops vegetative growth when it becomes a flower. Plants develop a dense cluster of pods at the terminal.

Threecornered alfalfa hopper. This insect can be found in soybean fields from the seedling stage through maturity. During the seedling stage its feeding causes girdled main stems; in later growth stages petioles are girdled. Plants damaged in early growth stages may not be noticed until they are much older and heavier. Because of the damaged stems, plants may lodge when stressed by wind, rain or cultivation equipment. The restricted flow of nutrients in girdled plants can reduce the number of pods produced. However, this type of damage rarely reduces yield because healthy plants adjacent to damaged plants compensate by producing higher yields. This is a phenomenon known as “plant stand compensation.” Main stem girdling is difficult to prevent with insecticide applications. A better management strategy for this type of damage is to manipulate seeding rates in order to obtain at least six undamaged plants per foot of row.

Saltmarsh caterpillar. These large, hairy, yellow caterpillars occasionally move into fields from weed hosts early in the season. When numerous, their damage may cause some loss in plant stands near field margins. Spot or perimeter treatments may be required if infestations threaten stands.

Woolly bear caterpillar. These are hairy, black and red caterpillars that cause damage similar to the saltmarsh caterpillar.

Armyworm and beet armyworm. Armyworms are conspicuously striped caterpillars that may occur locally in high numbers. Often they develop in pastures or roadside vegetation and march en masse into fields, eating as they go. They also can develop where moths lay eggs in the field. Young caterpillars feed close together, causing localized skeletonization and defoliation damage.

1Fehr, W. R. and C. E. Caviness. 1977. Stages of soybean development. SR80, Iowa State University. The most modern refinement of this system is described in Ritchie, S. W., J. J. Hanway, H. E. Thompson and G. O. Benson. 1989. How a soybean plant develops. SR53, Iowa State University.

Beet armyworms are green to brown with pale stripes along their sides, and a conspicuous black mark on each side of the body above the second pair of true legs. They prefer broad-leaved plants such as soybeans, and are generally more difficult to kill than armyworms because they are tolerant to certain insecticides.

Armyworms and beet armyworms in the Gulf Coast region of Texas rarely cause sufficient damage to warrant treatment. However, in the Texas Panhandle the beet armyworm is the primary foliar feeding caterpillar pest in soybeans.

Lesser cornstalk borer. Seedlings may be damaged by the lesser cornstalk borer. Larvae tunnel into the stem at the soil line, restricting the flow of nutrients to the upper portion of the plant and causing it to wilt and die. The very active, bluish-green caterpillars have brown stripes and are found inside the stem or in a silken tube just below the soil surface adjacent to the stem. These pests are usually found only in well drained, sandy soils; they thrive under dry conditions. Irrigation reduces potential damage. It is important to apply insecticide after planting before extensive stem damage has occurred

Cutworm. Larvae girdle soybean seedlings below the cotyledons, reducing plant stand. Larvae may also feed on foliage. As soybeans can withstand substantial stand reduction without a reduction in yield, control of cutworms is necessary only when unusually large populations occur.

Threecornered alfalfa hopper. Petiole girdling by adults and nymphs during the blooming and pod-filling stages can reduce yields.

Foliage feeding pests. Various caterpillars (including armyworms and beet armyworms), beetles and grasshoppers feed on soybean foliage. Because all cause defoliation, they are grouped together for damage estimation purposes. These pests can occur throughout the year, but are most significant from blooming to pod fill when defoliation can cause yield reductions (see Plant damage, p. 4). Infestations may develop very rapidly and completely defoliate soybean fields. Controlling these pests is complicated when several species are involved. Insecticide applied early in the season may cause resurgent populations, making it necessary to treat again (particularly when growing conventional varieties, groups VI-IX).

Velvetbean caterpillars, green cloverworms, soybean loopers, and cabbage loopers are the most common and severe defoliators of Texas soybeans. Velvetbean caterpillar moths migrate into Texas each year in large numbers, and caterpillar populations can build up rapidly. The larvae are green to brown with stripes along their sides, and have four pairs of abdominal prolegs. Although they are relatively easy to control with insecticides, populations often go undetected until significant damage has occurred. Green cloverworms have three pairs of abdominal prolegs and often require control in the Upper Gulf Coast area. Loopers are green caterpillars with two pairs of abdominal prolegs and a single pair of prolegs at the end of the body; they are sometimes marked with black. The soybean looper occasionally becomes abundant earlier in the season than other loopers, and populations are often composed of all sizes. It is not easy to see the differences between looper species, except at the pupal stage. Soybean loopers pupate in silk-like cocoons attached to the undersides of leaves. The pupae are white, cream or pale green in color. Cabbage looper pupae are brown and pupation occurs at the soil surface.

Armyworm. All three armyworm species feed on all growth stages of the soybean plant. Army-worms feed mainly on leaves, but also on pods.

Stink bugs. The southern green stink bug and brown stink bug are the most common species along the Gulf Coast of Texas, although occasionally other species such as the green stink bug are found. Adult stink bugs usually move into fields when soybeans begin to flower. Both adults and nymphs feed by inserting their mouthparts into the beans inside the pods. They also feed on stems, foliage and blooms. Pod feeding may reduce yield and quality of the soybeans, delay maturity (green bean effect), and increase the incidence of yeast spot seedling disease. Large numbers of nymphs can develop during the pod filling period. Because adult females deposit eggs in clusters, nymphs are extremely aggregated. Accurate sampling methods (such as the sweep net method described earlier) are required to estimate average field populations.

Corn earworm. This pest is also known as the cotton bollworm and soybean podworm. Female moths lay eggs on the terminal leaves of soybean plants. Larvae feed for a few days and then move down the plant to feed on developing soybeans. Occasionally, corn earworms are detected during vegetative growth stages. Large populations during the pod-filling stage can reduce yield. Infestations are most common where alternate hosts such as corn, sorghum and cotton are grown nearby.

Soybean stem borer. These long-horned beetles are occasional pests of soybeans in the Texas High Plains. Adults are 3/8 inch long, charcoal gray beetles with long antennae. The larvae are cream-colored, legless grubs. Larvae tunnel soybean stems in July and August, eventually girdling plants at the base. Plants may lodge and become difficult to harvest. Peak girdling activity occurs during September and October. Soybeans should be harvested as soon as possible to minimize losses to the stem borer.

Occasional early-season defoliators include cutworms, garden webworms, southern corn rootworm, and banded cucumber beetles Their feeding rarely becomes serious enough to warrant treatment. Several grasshopper species occasionally move into the margins of fields bordered by weedy areas, and at times they require spot treatments. Recently, large numbers of the bean leaf beetle were found in northeast Texas. Populations generally peak in the summer and early fall. Blister beetle larvae are considered beneficial because they destroy grasshopper eggs; however, the adult beetles defoliate soybeans by feeding on leaves, blooms, tender stems, and young pods. Other pests such as thrips, whiteflies and spider mites can damage foliage but rarely require treatment.

The term “biological control” refers to the suppression of pests by their natural enemies. Biological control tactics include the conservation, augmentation and importation of natural enemies. Conservation is the preservation of natural enemies that are already present. The best way to conserve natural enemies is to avoid using insecticides unnecessarily. Augmentation is the mass culturing and periodic release of a natural enemy. Many species of beneficial insects are sold for pest control in soybeans. However, the effectiveness of augmentation in soybeans is unknown and the Texas Agricultural Extension Service cannot provide guidelines for using this method. Importation is the introduction of non-native natural enemies. This method has been effective when an exotic pest has entered Texas without the natural enemies that help control the pest in its native country.

Natural enemies of insects that attack soybeans include spiders, lacewings, lady beetles, ground beetles, rove beetles, syrphid flies, flower flies, hover flies, true bugs (including minute pirate bugs, big-eyed bugs, assassin bugs and damsel bugs), predatory mites, and even fire ants. However, many important natural enemies are rarely seen, such as parasitic wasps and flies, nematodes, and pathogenic bacteria and fungi.

Generally, pesticides kill natural enemies as well as target pests. Once natural enemies have been destroyed, there is no natural (biological) proteciton against insect pests until natural enemy populations recover. This can cause outbreaks of secondary pests or rapid resurgence of pests that were initially suppressed by the pesticide treatment. Pest insects also can develop resistance to pesticides. Using nonchemical control methods, or pesticides that kill only the target pest, protects natural enemies. Insecticide applications should be avoided unless economically damaging levels of harmful pests are detected.

Bacillus thuringiensis (Biobit^�, DiPel^�, Design^�, Agree^� and others) is a biological insecticide labeled for control of several foliage-feeding larvae in soybeans. It is not recommended where heavy populations develop during the pod-filling period. This insecticide will not control defoliating beetles, grasshoppers or pod-feeding stink bugs. Using Bacillus thuringiensis requires a different approach to insect management. It is relatively slow acting, much more effective on small worms than large ones, and performs better when applied in large volumes of water per acre (10 to 15 gallons by ground application and 5 to 8 gallons by air) to ensure thorough plant coverage.

Biological insecticides generally suppress pest species without disrupting beneficial species that contribute to natural control. But to be used effectively, there must be regular, careful field monitoring and accurate analysis of the potential for plant damage. Precise application (timing, rate and coverage) is required. Application equipment must be clean so that there is no residue of conventional insecticide that may harm beneficial insects or the biological control organisms being applied.

Virus products (Spod-X^�LC, Gemstar^�LC) are very specific insecticidal viruses. They do not persist long in the field so correct timing of applications is important. The products do not affect beneficial insects.

Diflubenzuron (Dimilin^�) is a compound that prevents certain caterpillars from forming a new exoskeleton (skin) after molting. It is referred to as a “chitin synthesis inhibitor.” If pest populations are extremely large (two to three times higher than the threshold) and/or other pests are present (stink bugs, other caterpillar species, etc.) low rates of conventional insecticides may need to be used with diflubenzuron.

Pest thresholds for using biological insecticides may be lower than those for conventional chemical insecticides.

Spray applications are most effective, but they should not be made when wind velocity exceeds 15 miles per hour. Nozzle size and number, ground speed, and pump pressure influence the rate of output per acre. Always calibrate the sprayer carefully to ensure that the recommended rate is applied. For ground applications, one nozzle per row may be desirable on larger plants to obtain thorough coverage. For best results with aerial applications, flag swaths so they meet or overlap. Do not fly higher than 15 feet above the plant canopy to reduce drift and maximize coverage. When making any insecticide application, follow label directions. For calibration and safety information refer to B-1648, “Using Pesticides--Private Applicator Manual: General” (Texas Agricultural Extension Service).

Pollination is extremely important in producing many crops such as alfalfa, clover, vetch and cucurbits. Where pollinating insects are required for flower fertilization, the crop producer, insecticide applicator and beekeeper should cooperate closely to minimize bee losses. The following guidelines will reduce bee losses:

Policy for Making Chemical Control Suggestions

The information and suggestions in this publication reflect currently available management options. Our management suggestions are a product of research and are believed to be reliable. However, it is impossible to eliminate all risk. Conditions or circumstances which are unforeseen or unexpected may result in less than satisfactory results even when these suggestions are used. The Texas Agricultural Extension Service will not assume responsibility for risks.

Suggested pesticides must be registered and labeled for use by the Environmental Protection Agency and the Texas Department of Agriculture. The status of pesticide label clearances is subject to change and may have changed since this publication was printed. County Extension Agents and appropriate specialists are advised of changes as they occur.

The USER is always responsible for the effects of pesticide residues on livestock and crops, as well as for problems that arise from drift or movement of pesticides to the property of others. Always carefully read and follow the instructions on the product label.

This publication is based on a previous publication by Bastiaan M. Drees and Michael O. Way. The authors are grateful for the assistance of John A. Jackman, Bastiaan M. Drees, Roy Parker and Noel Troxclair.

Illustrations on page 5 are by James A. Kalisch and John Kalish. They are from Handbook of Soybean Insect Pests (1994) published by the Entomological Society of America, and are reprinted with permission.

¹Mexican bean beetle, Japanese beetle, thrips, lygus bug, seedcorn maggot, white grub, wireworm, aphid, leafhopper, cucumber beetle, alfalfa caterpillar, woolly bear caterpillar, painted lady (thistle caterpillar), garden webworm, silver-spotted skipper and two-spotted spider mite are not included in this guide, as they have not been found to be pests of Texas soybeans. The Mexican bean beetle and Japanese beetle have not been found in sufficient numbers to affect soybean production in Texas.

²Often a complex of caterpillar defoliators, including loopers, velvetbean caterpillar and green cloverworm, attack soybeans. Because damage by these species is similar and additive, use the same economic threshold for the insect complex. Treat when defoliation by this complex exceeds 40 percent prebloom, 20 percent during bloom and pod fill, and 35 percent from pod fill to harvest.

³To convert lbs./acre to kg/hectare use the formula: lbs./acre = kg/hectare
0.892

⁴An “X” indicates that restrictions on livestock grazing or feeding are not mentioned on the product label.

Carbaryl--Do not apply a combination of carbaryl and 2,4 DB herbicides to soybeans. Use lower rates for light to moderate populations and smaller instars and to provide maximum survival of beneficial insects and spiders. Use higher rates for heavy populations and larger instars. For grasshopper control, use the lower rate for nymphs on small plants or sparse vegetation in wasteland, rangeland, ditchbanks, rights-of-way, pastures, hedgerows and roadsides. Use the higher (1.5 lbs. AI/acre) rate for adult grasshoppers or applications to dense vegetation. Also labeled for cucumber beetles, alfalfa caterpillar, leafhoppers, thrips, webworms and painted ladies (thistle caterpillars)

Chlorpyrifos--Apply as broadcast spray using either aerial or ground equipment. Reapply as necessary to maintain control. On determinate soybeans, do not make more than one application after pod set. Also labeled for spider mite control (0.25 to 0.5 lb. AI/acre). When mites and eggs are in large numbers, apply a second spray 3 to 5 days after initial treatment to control newly hatched nymphs. Lorsban may also be applied through sprinkler irrigation systems. Do not apply more than 3 lbs. AI chlorpyrifos per acre per season, nor apply the last two treatments closer than 14 days apart.

Diflubenzuron--See discussion in "Biological insecticides." For aerial application, apply when larvae are small (less than 1/2 inch). Apply in sufficient (1 to 3 gals. per acre) water to achieve uniform coverage of foliage. For ground application, apply recommended rate in 9 to 35 gals. of water per acre to achieve uniform coverage. Do not make more than two applications per season. From 3 to 5 days may be required before populations are reduced. Do not rotate crops other than soybeans or cotton until 6 months following last application. Do not apply to lakes, streams, ponds or other bodies of water.

Es-fenvalerate--Do not feed or graze livestock on treated plants. Do not exceed 0.2 lb. AI per acre per season. When applying in nonvoliatile vegetable oils use a total spray volume of 1 or more quarts.

Methomyl--Also labeled for thrips. For aerial application of Lannate^� LV as a low-volume spray, ensure that equipment is capable of delivering small spray droplets for thorough coverage, and that equipment is adjusted to distribute spray uniformly over the spray swath. Apply when wind, temperature and humidity will allow spray to be delivered to the target area. Make sure local regulations do not prohibit low-volume aerial sprays. Apply in a minimum total spray volume of 0.53 gal. per acre. Water or once-refined vegetable oil may be used as the spray carrier. Continue to apply at 5- to 7-day intervals or as needed to maintain control.

Methyl parathion--Do not apply more than twice per growing season. Products containing methyl parathion are also registered for use on thrips, garden webworms, two-spotted spider mites, leafhoppers, and silver-spotted skippers.

Permethrin--Apply by air or ground. Do not apply more than 0.4 lbs. AI per acre per season. Apply Pounce^� 25 WP in a minimum of 1 gal. finished spray per acre by air or 5 gallons with ground equipment. When applying Pounce^� 3.2EC in nonvolatile vegetable oil, apply in a minimum of 1 qt. total volume per acre using equipment calibrated to give adequate coverage. When applying in water by aircraft, 1 qt. of oil may be substituted for 1 qt. water per gallon of finished spray.

Thiodicarb--Apply in a minimum finished spray volume of 2 gals. per acre by air or 5 gals. per acre by ground. Use lower rates for low to moderate populations and maximum protection of beneficials. Refer to product label for special instructions for cutworm applications.

Tralomethrin--For aerial applications, use a minimum of 1 gal. of water per acre or 1 qt. of at least once-refined crop oil per acre. For ground applications, use a minimum of 5 gals. of water per acre for thorough coverage of the foliage.

Additional Insecticide Products Registered For Use On Soybeans (Note: The information below is presented for completeness of available product information only. This listing does not constitute a recommendation for use of these products in Texas soybean production.)

Carbofuran (Furadan^� 4F) -- Labeled for grasshopper control as a foliar application using 1/4 to 1/2 pt. in 20 or more gals. of water per acre. Do not apply within 21 days of harvest and do not graze or feed foliar-treated forage to livestock or cut for silage or hay.

Ethyl phosphosphorodithioate (Di-Syston^�15%) -- Labeled for aphids, leafhoppers, mites, thrips (except flower thrips), and Mexican bean beetle. Place granules in a 4-inch band over the seed furrow behind the planter shoe and in front of the press wheel, or in a band on each side of the seed furrow at planting time. 6.7 lbs./acre. Allow at least 75 days between application and harvest for forage or hay.

Malathion (Malathion ULV Concentrate) -- Labeled for grasshopper and green cloverworm control at a rate of 8 fl. oz. per acre, undiluted. Do not harvest or graze for 7 days following application.

Methoxychlor (Methoxychlor 4L) -- Labeled for velvetbean caterpillar, blister beetles, garden webworm, leafhopper and fall armyworm at a rate of 1 to 3 qts. per acre, with a pre-harvest interval of 7 days.

Neem oil (Trilogy^�) -- Labeled as a broad-spectrum miticide/insecticide/fungicide.

Permethrin plus methyl parathion (Pounce^� Plus Methyl Parathion 2-5EC) -- Labeled for control of cabbage looper, corn earworm, soybean looper, velvetbean caterpillar, bean leaf beetle, alfalfa looper and garden webworm at 6.4 to 12.8 fl. oz. per acre and for stink bug and threecornered alfalfa hopper at a rate of 12.8 fl. oz. per acre. This product is convenient when a complex of pests occurs that does not respond to the ingredients in this product applied separately. Application may be made with air or ground equipment. Use a minimum of 1 gal. of water per acre with aircraft or 5 gals. of water per acre with ground equipment. Do not make more than two applications per season. Do not apply within 40 days of harvest. Do not feed or graze soybean forage. Do not plant rotational crops within 60 days of last application.

Phorate (Thimet^� 15G and 20G) -- Labeled for the early season control of thrips, mites and other insects as an at-plant application at a rate of 12 oz. (Thimet 15G) and 9.0 oz. (Thimet 20G) per 1000 feet of row.

N-methyl carbamate (Slam^�) -- Labeled for control of diabroticine beetle adults. Apply 0.5-0.75 lb/acre. 0 days pre-harvest interval.

Conversion table: Pounds of active ingredients (AI) per acre to amount of formulation per acre. For additional conversions use these formulas:

lb. AI per acre � lb. formulation per gal. = gal. formulation per acre; lb. AI formulation per acre � % AI formulation per acre � 100 = lb. formulation per acre

Insecticide and formulation	Pounds of active ingredients (AI) per acre converted to amount actual product per acre
carbaryl
Sevin^� 80S	0.5 lb. AI. = 0.63 lb./acre; 1.0 lb. AI = 1.25 lbs./acre; 1.5 lbs. AI = 1.87 lbs./acre; 2.0 lbs. AI = 2.5 lbs./acre
Sevin^� 50WP	0.5 lb. AI. = 1.0 lb./acre; 1.0 lb. AI = 2.0 lbs./acre; 1.5 lbs. AI = 3.0 lbs./acre; 2.0 lbs. AI = 4.0 lbs./acre
Sevin^� XLR Plus	0.5 lb. AI. = 0.5 qt./acre; 1.0 lb. AI = 1.0 qt./acre; 1.5 lbs. AI = 1.5 qts./acre; 2.0 lbs. AI = 2.0 qts./acre
chlorpyrifos
Lorsban^� 4E	0.25 lb. AI = 0.5 pt./acre; 0.5 lb. AI = 1.0 pt./acre; 0.75 lb. AI = 1.5 pts./acre; 1.0 lb. AI = 2.0 pts./acre
Lorsban^� 15G	5.7 lbs. AI = 38.0 lbs./acre
diflubenzuron
Dimilin^� 25W	0.03125 lb. AI = 2.0 oz./acre; 0.0625 lb. AI = 4.0 oz./acre
es-fenvalerate
Asana^� 1.9EC	0.0125-0.025 lb. AI = 0.85-1.7 fl. oz./acre; 0.025 0.05 lb. AI = 1.7-3.4 fl. oz./acre
methomyl
Lannate^� LV	0.13 to 0.25 lb. AI = 0.43 to 0.83 pts./acre; 0.38 lb. AI = 1.27 pts./acre; 0.5 lb. AI = 1.67 pts./acre; 1.0 lb. AI = 3.3
pts./acre
methyl parathion
Methyl Parathion 4E and
MP 4 EC	0.25 lb. AI = 0.5 pt./acre; 0.38 lb. AI = 0.76 pt./acre; 0.5 lb. AI = 1.0 pt./acre; 1.0 lb. AI = 2.0 pts./acre
Methyl Parathion 7.5	0.25 lb. AI = 0.27 pt./acre; 0.38 lb. AI = 0.41 pt./acre; 0.5 lb. AI = 0.53 pt./acre; 1.0 lb. AI = 1.1 pts./acre
Penncap-M	0.25 lb. AI = 1.0 pt./acre; 0.5 lb. AI = 2.0 pts./acre; 0.75 lb. AI = 3.0 pts./acre; 1.0 lb. AI = 4.0 pts./acre
permethrin
Ambush^� 25W and
Pounce^� 25WP	0.05 lb. AI = 3.2 oz./acre; 0.1 lb. AI = 6.4 oz./acre; 0.2 lb. AI = 12.8 oz./acre
Ambush^� 25W and
ounce^� 3.2EC	0.05 lb. AI = 2.0 fl. oz./acre; 0.1 lb. AI = 4.0 fl. oz./acre; 0.2 lb. AI = 8.0 fl. oz./acre
thiodicarb
Larvin^� 3.2	0.25-0.4 lb. AI = 10.0-16.0 fl. oz./acre; 0.45-0.75 lb. AI = 18.0-30.0 fl. oz./acre; 0.5-0.75 lb. AI = 20.0-30.0 fl. oz./acre
tralomethrin
Scout^�	0.014-0.017 lb. AI = 6.0-7.0 fl. oz./acre; 0.015-0.019 lb. AI = 6.4-8.0 fl. oz./acre
Scout^� X-tra^TM	0.012-0.016 lb. AI = 1.73-2.33 fl. oz./acre; 0.016-0.024 lb. AI = 2.33-3.33 fl. oz./acre

Educational programs of the Texas Agricultural Extension Service are open to all people without regard to race, color, sex, disability, religion, age or national origin.

Issued in furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of Congress of May 8, 1914, as amended, and June 30, 1914, in cooperation with the United States Department of Agriculture. Chester P. Fehlis, Deputy Director, Texas Agricultural Extension Service, The Texas A&M University System.

Fehr and Caviness (1977)1	Plant development
VE	Emergence
VC	Cotyledon + unfolding unifoliate leaves
V1	First node trifoliate leaves + photosynthesis
V2	Second node
V3	Third node
V4	Fourth node
V5	Fifth node
V6	Sixth node
V(n)	Nth node
R1	Beginning bloom
R2	Full bloom
R3	Beginning pod development
R4	Full pod
R5	Beginning seed
R6	Full seed
R7	Beginning maturity
R8	Full maturity leading to harvest


Soybean stem borer	Saltmarsh catarpillar	Banded cucumber beetle

Soybean thrips	Bean leaf beetle	Blister beetle



Southern green stinkbug	Beet Armyworm	Silver spotted skipper



Geeen clover worm	Velvet bean caterpillar	Three-cornered alfalfa hopper



Corn earworm	Fall armyworm	Black cutworm