Whole Document Navigator (Click Here)    ---------------------------------- Top of Document Description of Soil Pests -Cucumber Beetles (or Southern Corn Rootworm) -Cutworms -Grubs -Lesser Cornstalk Borers -White-fringed Beetles -Wireworms -Other Soil Pests Description of Foliage, Stem and Above Ground Plant Feeders. -Fall Armyworms -Others Description of Ear Feeders -Corn Earworms -Fall Armyworm -Stink Bugs -Rice Weevils Field Inspection of Field Corn -Sampling -Thresholds -Aflatoxin Control of Insect Pests Additional Information Footnotes Disclaimer Copyright Infomation

Insect Management in Field Corn ¹

Richard Sprenkel ²

Field corn has a number of pest insects. There are some serious soil pests that attack the crop as well as some insects that attack the foliage and tassels creating a great deal of damage.

The pests that attack the ears and its parts are perhaps the most important since damage at this stage comes at a time when the grower has a maximum dollar input in the crop.

Although an enumeration of all the pests of corn would create a long list, there are several that are encountered by the Florida grower more frequently and more attention will be given to these insects.

Description of Soil Pests

Cucumber Beetles (or Southern Corn Rootworm)

There are several species of cucumber beetles (banded, striped, spotted) that attack field corn. The adult beetles feed on the foliage, but the major source of damage is brought about by yellowish-white fragile larvae (worm shaped grubs) that tunnel and attack the roots of the plant. The lower part of the stalk is often bored into by the grub. The small thin worm is difficult to extract from the plant due to its fragility and care must be taken in dissecting or cutting apart infested plant tissue.

Control of the worm is difficult and application of insecticides must be made at planting time or shortly thereafter if this pest is a suspect. Use of the contact insecticides/nematicides (Counter) at planting time usually does a good job of controlling the corn rootworms.

Once the plant is infested, little can be done to control the pest. The cucumber beetle larvae are more severe on wet soils than on those with higher clay content, or where corn is strip tilled into living mulch.

Cutworms

The cutworm has always been a serious pest of young field corn seedlings. The worms are stout and dark colored.

CREDITS: University of Georgia

Figure 1. Cutworm with damaged young corn plant.

During the day they stay just below the soil surface under trash or in cracks in the soil around the plant. Most damage is done at night when they climb the plants and feed on the foliage; however, they will cut plants off at the soil surface. The "dirty looking" worm can often be found close to the plant upon which it has previously fed. It is generally located from just under the soil surface to several inches deep. The worm rolls into a ball when disturbed.

The cutworms can generally be controlled by baits which give more satisfactory results when applied late in the afternoon. Cutworms attack nearly all plants except those with hard woody stems. However, good cutworm control can be obtained by using sprays that are directed at the base of the plant.

Grubs

The common grubworm is an occasional pest of corn. Like the mole cricket, damage is due to the tunneling of the grub. Plant damage is further magnified by the grub feeding on the roots of the plant.

The grub is identified by a brown head, six prominent legs and a smooth shiny body with the rear end purple to black in color due to the body contents showing through the skin. Most vegetables, field or cultivated plants are attacked.

The adults or May beetles are nocturnal and probably do little or no economic damage. The grubs can live approximately three years in the soil and therefore emergence of adults is often heavier in certain years than in others. Recommended control for the grub is the same as for the wireworm.

Lesser Cornstalk Borers

This small larva is one of the most serious soil pests of corn. The caterpillar reaches a maximum of 1/2-5/8 inch in length when full grown. The worms have alternate narrow bands of purplish-wine and aqua blue colors encircling their bodies and the worms wiggle actively when disturbed.

CREDITS: R. Bessin, University of Kentucky

Figure 2. Lesser cornstalk borer with damaged corn plant.

The borer usually makes its entry by drilling into the main stem of the plant just below the soil surface. The worm then eats its way up and down the corn seedling. It constructs a sticky silken tube that will be found dangling from the corn root. The fragile tube is attached at the point of entry and is about 3/4-1 inch in length and is covered with soil particles. The borer can often be found inside the tube if the infested plant is gently spaded out of the soil and the plant carefully shaken to remove loose soil.

The lesser cornstalk borer builds up on grass and sod crops and prefers hot dry weather and sandy soil. Land intended for corn that has existing grass crops should be plowed thoroughly or killed 3 - 4 weeks in advance of planting. Since the pest prefers hot weather, the later corn is planted in the season the greater will be the risk of encountering the lesser cornstalk borer. If corn can be irrigated, this operation can be a good cultural control technique in reducing the pest.

If chemicals are to be used, timing can be critical. The contact insecticides/nematicides (Counter, Force, and Fortress) applied at planting reduce populations. Other chemicals more specific to lesser cornstalk borer should also be applied at planting time or immediately after the pest appears and reaches damaging populations.

Corn plantings are usually infested in irregular "size" and shaped patterns in the field with young plants suddenly dying as if they have "damping off" disease. Corn plants that survive attack often produce suckers and the plant becomes stunted in height and "bushy" in appearance.

White-fringed Beetles

This insect is a pest of crops grown in the western and northern parts of the state. It attacks over 360 species of plants which include field and vegetable crops.

The adult beetle is about 1/2 inch long and is grey in color with faint white stripes on its sides. Adults feed on the leaves of plants, but the critical damage is caused by the grub-like legless larvae about 3/8-1/2 inch in length which feed on the lower part of the plant stem and root. The grub's damage is confined to plant parts below the soil surface as the grub does not climb or feed on the foliage.

The adult is unable to fly and the spread of the insect is brought about by the beetle's walking 1/2-3/4 mile per year or being moved by man, equipment, etc.

Wireworms

These "worms" are the larval stage of the click beetles. They are quite slender, yellowish in color with visible body segmentation.

CREDITS: R. K. Sprenkel, University of Florida

Figure 3. Wireworm (click beetle larvae).

Their bodies are hard and "slick" feeling. Wireworms vary in size from 1/2 up to 2 inches in length.

These worms live in the larval stage for several years depending on the species. They can inhabit the soil to a depth of up to 5 feet and are very difficult to find.

No good sampling technique exists for determining the wireworm populations. The soil can be dug up and sifted through 1/8 to 1/4 inch mesh screen to see if wireworms are present, but this is a very laborious task and can be dangerously misleading. Wireworms can also be "baited" with ears of corn that have been shucked. This can be done by placing the ears randomly on the soil surface in a field being readied for planting. If wireworms are present they may be attracted to the corn ear and can be seen feeding on the seed after several days.

These methods are only indications and can be very misleading. It is important to keep crop history records on fields since the life cycle of this pest is such that if they were experienced in the past several years, then they could very well still be present in the larval stage.

Wireworms can be reduced by flooding, frequent and deep plowing, and by chemical means.

Wireworms have a tendency to build up on grass and sod crops. Growing corn behind these crops can often lead to problems unless the plants are killed several weeks in advance of planting.

It is difficult to control wireworms with chemicals after the crop is planted. If the worms are suspected or if they are present, then preplant insecticide treatments may be applied. Once the seeds are in the ground the damage is done before the grower is aware of it.

Wireworms damage corn by eating into the seed and consuming the endosperm. Wireworms will also eat into the root and feed up or down the main stem or root and kill the seedling. The symptoms are: poor stand, weak seedlings, or seedlings that look good and suddenly die.

Use of the contact soil insecticides/nematicides usually has a suppressive effect on wireworm populations.

Other Soil Pests

Other soil insects that attack the seed or underground parts are numerous. However, flea beetles, billbugs, ants (in conjunction with corn root aphids), and even termites are often reported to damage corn. Thorough preparation of soil before planting, or killing the crop 3 - 4 weeks ahead of planting, particularly after sod and grass crops, destruction of previous season's crop residues well in advance of planting and use of contact nematicides/ insecticides generally are thought to be good practices for Florida grown corn.

Description of Foliage, Stem and Above Ground Plant Feeders.

Fall Armyworms

The fall armyworm is probably the most damaging foliage feeder of corn grown in Florida. The migrating moths lay egg masses of 100-150 eggs generally on the undersurface of the corn leaves. The buff colored egg masses hatch within a few days and numerous larvae move over the corn plants.

CREDITS: R.K. Sprenkel, University of Florida

Figure 4. Fall armyworm egg mass on corn leaf.

The larvae will go from one plant to another and seem to first locate in tight leaf axils or whorls. Young plants can be devastated by whorl feeding.

CREDITS: R.K. Sprenkel, University of Florida

Figure 5. Fall armyworm damage.

A large majority of the so-called budworms in Florida grown corn are fall armyworms. The larval stage reaches approximately 1 1/2 inches in length within 14-21 days, then it drops from the plant and pupates in the soil.

The fall armyworm moth migrates in large numbers and each female can lay 1000-1500 eggs. Therefore, corn under attack has the potential of having thousands of worms appearing at once.

Fall armyworms are variably colored but are generally brownish-grey to green in color. The head capsule is usually shiny dark brown to black in color and the front of the head has a white or yellow colored inverted "Y". The fall armyworm also will feed on the leaves, tassels and the ears of the corn. Little can be done to control migrating pests. Chemical control is very difficult to obtain due to the following:

1. The females lay covered egg masses;
2. The egg masses are located on the undersides of the leaves;
3. The young larvae often seek out the tight crevices of the plants or feed deep in the whorls.

It appears that corn that is planted early in the season coupled with the selection of a variety that matures as quickly as possible is one of the best control measures that can be practiced since fall armyworms begin to migrate when weather warms up and become more numerous as the weather gets hotter.

Others

Other foliage feeders such as beet armyworm, corn earworm, southern armyworm, yellow-striped armyworm, true armyworm (armyworm), aphids (plant lice), chinchbugs, grasshoppers, numerous types of beetles and mites may attack the cornplant. These aforementioned pests can cause problems under the proper conditions but their attack is usually less intense or frequent than the fall armyworm.

Description of Ear Feeders

Corn Earworms

The corn earworm is probably the most prominent pest of the ear. The female lays her eggs one at a time usually on the developing silks. Upon hatching the small larvae feed on the silk and will enter the tip of the ear where they will feed on developing kernels. In most cases the larval entry is at the silk end of the ear and feeding is confined to a large extent at the tip end of the ear.

The corn earworm will reach 1 1/2 inches in length in about 14-21 days. The larvae are found in a variety of colors such as several shades of green, brown, tan, yellow, pink and when small may appear almost black in color.

CREDITS: R. K. Sprenkel, University of Florida

Figure 6. Corn earworm larvae.

The head capsule is generally yellow to orange in color. The corn earworm like the fall armyworm curls into a ball when disturbed.

The corn earworm seldom enters the ear from its sides as does the fall armyworm. Early planted, early maturing corn is recommended in order to escape the heavier pest populations that occur as the weather becomes warmer. Chemical control is effective only when the timing of application kills the larvae before it enters the confinement of the ear.

Fall Armyworm

Fall armyworm larvae also feed on the developing kernels. The caterpillar may enter the ear from the sides as well as from the tip .When populations are heavy it is not unusual to find several worms within a single ear.

Stink Bugs

Stink bugs are frequently found in large numbers feeding on developing ears of corn.

CREDITS: University of Florida

Figure 7. Stink bug on corn husk.

The nymphs (immature stage) as well as the adults pierce the shuck and feed on the developing kernels. Activity is most concentrated from the time kernels begin to form through the milk stage of development. Feeding can occur through the hard dough stage. Damage may appear as missing or shrunken kernels. Severe damage causes curved ears to form.

CREDITS: R.K. Sprenkel, University of Florida

Figure 8. Corn ear damaged by stink bugs.

Heavy populations can reduce not only yields but also the quality of the grain.

Rice Weevils

The adult rice weevil is about 1/16 inch in length and is dark brown to nearly black in color. The females chew slight cavities in the kernels of grain, deposit an egg, and then seal the hole. The female can lay 300-400 eggs. The eggs hatch into a white legless grub which feeds on the interior of the corn kernels.

The weevils can infest corn in the field and can attack the kernels after the corn has reached the hard dough stage as well as continue the attack in storage. Harvesting corn as soon as moisture content will allow is recommended in order to avoid weevil infestations. The longer grain is allowed to go unharvested, the more chance of weevil outbreak.

Field Inspection of Field Corn

Sampling

Corn should be monitored on a weekly basis throughout the growing season for the major foliage-feeding pests. Samples should be selected at random and be representative of the field being monitored.

A sample consists of examination of five consecutive corn plants. The first plant should be selected at random.

Before tasseling, check both leaf surfaces and the stalk from the top of the plant to the ground level paying particular attention to the uppermost leaves. Examine the silks and ears carefully after the plants have reached the reproductive stage.

The number of samples to be taken is determined by the size of the field. Normally, one sample should be taken for every two acres of field size. At least 20 samples should be taken regardless of field size. Each week the location of samples should be different. One way of doing this is to enter the field at a different point and walk a different route each week.

Generally, no more than 20-25% of the samples should be taken at the edge of the field. However, a few sites should be taken on the edge 10-15 rows of each field to check for those pests that may be migrating into the field (grasshoppers, armyworms, and stink bugs).

Soil-inhabiting insects in corn present special sampling problems. Because of their feeding or hiding below the soil surface, sampling procedures have not been developed which give a true measure of the size of the pest population. However, wireworms and lesser cornstalk borers can be sampled by digging a 6-8 inch deep trench along one foot of row when the corn is in the seedling stage. Wireworms can be located by sifting the soil through a coarse screen. Lesser cornstalk borers can be found by carefully digging up the plants along the trench and examining the roots for the silken tubes and larvae.

Cutworms are usually monitored by the damage they do. The number of cut corn plants in each sample (five plants) should be noted. If cut plants are found, check the top two inches of soil extending four inches from both sides of row where the sample was taken. Cutworms normally spend the day just under the soil surface or under debris close to their feeding sites.

Since white grubs take several years to develop, they may be present in a field when corn is planted. The presence of white grubs is easiest to check immediately following the tillage operations used to prepare the seed bed (plowing, disking, etc.). Check the top two inches of soil in several 3 ft. x 3 ft. areas throughout the field for the white grubs.

Thresholds

Fall Armyworm - Before tasseling 5% of the plants with egg masses or newly hatched larvae or 50% of plants with small worms in the whorls.

Wireworms - 20,000 per acre (approximately 1 per 2 sq ft of soil area).

Lesser Cornstalk Borer - 10% of seedlings with damage and worms present.

Cutworms - 10% of seedlings cut and cutworms present.

White Grubs - 1 per square yard at the time of land preparation.

Corn Earworm - 50% of the plants with small worms in the whorls. Chemical control has not been shown to be feasible to control corn earworms or fall armyworms after they have entered the ear.

Corn Leaf Aphid - Treatment may be justified when there are 50 or more aphids on 50% or more of the plants and damage is evident.

Stink Bug - For corn in the early silk through milk stage, treatment may be justified when there is 1 stink bug per 5 plants. From the end of milk through the hard dough stages treatment may be justified when there is an average of one stink bug per plant. Only stink bugs 1/4 inch or longer should be considered when determining thresholds.

Grasshoppers - Defoliation of 30% or more may justify treatment. Treatment may also be justified if 20% or more of the plants have feeding damage on green silks.

Chinch Bugs - Treatment is usually justified when there are 100 or more chinch bugs per plant and wilted leaves are evident.

Southern Corn Rootworm - Treatment may be justified if 10% of the plants show damage due to larval feeding (stunted, lodge or killed). Treatment for adults may be justified if green silks are trimmed back to 1/2 inch or less and there are 5 or more spotted cucumber beetles per plant.

Aflatoxin

Aflatoxin is a very dangerous toxin given off by a fungal pathogen that occurs frequently in field corn grown under Florida conditions. Insects that feed on the corn ear open avenues of entry for the fungus. Control of ear feeders by planting early and harvesting on time is thought to reduce the risk of this disease.

Control of Insect Pests

Suggested chemical control recommendations for the major corn insect pests in Florida are presented in Table 1 .

The use of trade names in this publication is solely for the purpose of providing specific information. It is not a guarantee or warranty of the products named and does not signify that they are approved to the exclusion of others of suitable composition. It is impossible to relate to the user all the warnings and limits to use that are printed on the label. Therefore it is the responsibility of the user to read and understand the label. Many questions arise as to waiting periods if corn is to be used for forage rather than for grain. Also the question arises as to what type animals may be fed treated forage. The following list was prepared to answer some of these questions but is not a substitute for reading the labels.

RUP=Restricted Use Pesticide

Ambush: RUP Do not apply more than 0.6 lb ai/a/season. Allow a minimum of 6 days between treatments. Toxic to fish.

Asana XL: RUP Do not exceed 0.25 lb ai/a/season.

Capture 1.15G: RUP Do not exceed 0.3 lb ai/season. Do not harvest within 30 days.

Comite: Do not apply more than 1 time per season or harvest within 30 days following application.

Counter: RUP Do not graze or cut for forage within 30 days of treatment. Do not exceed 6.5 pounds of Counter CR per acre.

Dimethoate: Do not make more than 3 applications/year. Do not feed or graze within in 14 days of last application. Do not apply to corn during pollen-shed period.

Force: RUP Do not apply more than one application/crop. Rotational crops may be planted no sooner than 30 days after application. Must be incorporated into soil.

Fortress: RUP Do not make more than one application/year. Crop rotational intervals: corn- anytime; other crops- 30 days.

Furadan 4F: RUP Do not make more than 2 foliar applications/season or one if also used as a soil treatment. This is the only formulation registered for use in Florida. Note: Carbofuran (Furadan) is a chemical which can travel (seep or leach) through soil and can contaminate ground water which may be used as drinking water. Carbofuran has been found in ground water as a result of agricultural use. Users are advised not to apply carbofuran where the water table (ground water) is close to the surface and where the soils are very permeable, i.e., well-drained soils such as loamy sands. Your local agricultural agencies can provide further information on the type of soil in your area and the location of ground water.

Lannate LV: RUP No more than 2.25 lb ai/a/crop. Maximum of 10 applications/crop.

Lannate SP 90 %: RUP No more than 2.25 lb ai/a. Maximum of 10 applications/crop.

Lorsban: RUP (EC only) Do not apply more than 15 pt 4 EC or 13 lbs 15 G /a.

Mocap: RUP To be applied from preplant to layby. Do not apply as furrow treatment or allow Mocap to contact the seed. Make only one application/season.

Penncap - M: RUP Do not apply more than 12 pt/a/year. Do not apply during pollen shed if bees are foraging in area to be treated.

Phorate: RUP Do not graze or cut for forage within 30 days of treatment. Do not make more than 1 application over the plant. Do not apply under prolonged drought conditions. Do not use in-furrow application.

Pounce: RUP Do not apply more than 0.6 lb/ai/a/season. Allow a minimum of 6 days between treatments.

Sevin: Repeat applications as needed up to a total of 4 times but not more often than once every 14 days. Observe bee caution. No more than 8 qt/a/crop. For 80 WSP formulation, do not apply more than 10 lb/a/crop.

Telone II: RUP Early entry is restricted for 5 or more days. Oral and posted warnings are required. Also use is restricted in certain Florida counties.

Tracer: Do not apply more than 6 oz/a/year or 1.88 lb ai/a/year. Do not apply within 28 days of grain or 7 of forage harvest.

Warrior Z : RUP Do not apply more than 0.12 lb ai/ac (0.96 pts/a) /crop.

Additional Information

Corn Insect Pests http://www.isis.vt.edu/~fanjun/ text/Link_pest11.html.

Crop Data Management Systems (Label Search) http://www.cdms.net/manuf/manuf.asp.

Higley, L. and D. Boethel Eds. 1994. Handbook of Soybean Insect Pests. Entomological Society of America, Handbook Series, 144 pp.

Steffey, K., M. Rice, J. All, D. Andow, M. Gray, J. Van Duyn. Eds. 1999. Handbook of Corn Insects. Entomological Society of America, Handbook Series, 174 pp.

Tables

Table 1.

Trade Name (Common Name)	lb ai/a	Formulation/a	a/ga/ or lb	Min Days to Harvest and Restrictions
APHIDS
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21-corn leaf aphid, oat bird-cherry aphid
Dimethoate 4 EC (dimethoate)	0.33-0.5	0.67-1 pt	12-8	14 Do not apply if bees are visiting the area
Lannate 2.4 LV (methomyl)	0.23-0.45	0.75-1.5 pt	10.7-5.3	3-forage; 21-ear,fodder
Lannate SP 90 % (methomyl)	0.23-0.45	0.25-0.5 lb	4-2	3-forage; 21-ear, fodder
Lorsban 4 E (chlorpyrifos)	0.5-1	1-2 pt	8-4	14-graze, silage; 35-grain, fodder
Methyl 4 EC (methyl parathion)	0.25	0.5 pt	16	12-corn leaf aphid Do not apply during pollen shed.
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21 For suppression only.
ARMYWORM (See also: Beet Armyworm, Fall Armyworm)
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30-grain, fodder
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21 For true armyworm.
Bacillus thuringiensis	See various brand labels.
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21, 0-for green forage
Lannate SP 90 % (methomyl)	0.23-0.45	0.25-0.5 lb	4-2	3-forage; 21-ear, fodder
Lorsban 4 E (chlorpyrifos)	0.5-1	1-2 pt	8-4	14-graze, silage; 35-grain, fodder
Lorsban 15 G (chlorpyrifos)	6-8 oz/1000 ft row (post plant)
Methyl 4 EC (methyl parathion)	0.25	0.5 pt	16	12 Do not apply during pollen shed.
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	30-
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
Tracer (spinosad)	0.031-0.094	1-3 oz	128-43	28-grain, fodder; 7-forage
Warrior T (cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
BEAN BEETLES
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21, 0-for green forage
Dimethoate 4 EC (dimethoate)	0.33-0.5	0.67-1 pt	12-8	14 Do not apply if bees are visiting the area.
Warrior T (cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
BEET ARMYWORMS
Lannate 2.4 LV (methomyl)	0.45-0.5	1.5 pt	5.3	3-forage, 21-ear, fodder
Lannate SP 90 % (methomyl)	0.23	0.5 lb	2	3-forage; 21-ear, fodder
Lorsban 4 E (chlorpyrifos)	0.5-1	1-2 pt	8-4	14-graze, silage; 35-grain, fodder
Tracer (spinosad)	0.062-0.094	2-3 oz	64-43	28-grain, fodder; 7-forage
Warrior T (cyhalothrin)	0.03	3.84 oz	33.3	21
BILLBUGS
See Maize Billbug for treatment
BUDWORMS
Budworms are composed of Fall Armyworms and Corn Earworms. Refer to those for treatment.
CEREAL LEAF BEETLES
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
CHINCH BUGS
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Counter CR (terbufos)	1.3 max	4.5-6 oz/1000 ft row		30 Apply at planting.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting. For suppression only.
Lorsban 4 E (chlorpyrifos)	0.5-1	1-2 pt	8-4	14-graze, silage; 35-grain, fodder
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		Banded at planting.
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
Warrior Z (lambda cyhalothrin)	0.03	3.84 oz	33.3	21
CORN BORERS (See also: European Corn Borers)
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30-grain or fodder
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21 For southwestern corn borer.
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30-grain or fodder
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
CORN EARWORMS
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30 grain or fodder
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21 Begin treatments at or before silking.
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Lannate 2.4 LV (methomyl)	0.23-0.45	0.75-1.5 pt	10.7-5.3	21-fodder, ears; 3-forage
Lannate SP 90% (methomyl)	0.23-0.45	0.25-0.5 lb	4-2	21-fodder, ears; 3-forage
Lorsban 4 EC (chlorpyrifos)	0.75-1	1.5-2 pt	5.3-4	14-graze,silage; 35-grain, fodder
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30-grain or fodder
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
Tracer (spinosad)	0.062-0.094	2-3 oz	64-43	28-grain, fodder; 7-forage
Warrior Z (lambda cyhalothrin)	0.015-0.025	1.92-3.2 oz	66.7-40	21
CORN ROOTWORM (See: Cucumber Beetles)
CUCUMBER BEETLES
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30-grain or fodder
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Capture 1.15G (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row	2.5-2	30 Band over open seed furrow at planting. Must be incorporated.
Capture 2 EC (bifenthrin)	0.006	6.4-8 oz/1000 ft row		30
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting or cultivation.
Dimethoate 4 EC (dimethoate)	0.33-0.5	0.67-1 pt	12-8	14 Do not apply if bees are visiting the area.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting or within 30 days of emergence.
Fortress 5 G (chlorethoxyfos)	3-4.5 oz/1000 ft row for (larvae)
Lannate 2.4 LV (methomyl)	0.23-0.45	0.75-1.5 pt	10.7-5.3	21-fodder, ears
Lannate SP 90% (methomyl)	0.22-0.45	0.25-0.5 lb	4-2	3-forage
Lorsban 4 E (chlorpyrifos)	0.5-3.0	6 pt (PPI-larvae), 1-2 pt	8-1.3	14-graze, silage; 35-grain, fodder
Methyl 4 EC (methyl parathion)	0.25	0.5 pt	16	12 Do not apply during pollen shed.
Mocap EC (ethoprop)	1.4 oz/1000 ft row for (larvae)
Mocap 10 G (ethoprop)		10.5 oz/1000 ft row		Apply at planting.
Phorate 20 G (phorate)		6 oz/1000 ft row		Apply at planting.
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30-grain or fodder
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
CUTWORMS
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30-grain or fodder
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21
Baythroid 2 (cyfluthrin)	0.13-0.025	0.8-1.6 oz	160-80	21; 0-for green forage
Capture 1.15G (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row	2.5-2	30 Band over open seed furrow at planting. Must be incorporated.
Capture 2 EC (bifenthrin)	0.005-0.006	6.4-8 oz 1000 ft row	0.1-0.19	30 Apply in seed furrow. Must be incorporated.
Counter CR (terbufos)		6 oz/1000 ft row		30 Aapply at planting. For suppression only.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting.
Fortress 5 G (chlorethoxyfos)		3-3.75 oz/1000 ft row		Apply in furrow at planting.
Lannate 2.4 LV (methomyl)	0.45	1.5 pt	5.3	21-fodder, ears; 3-forage
Lorsban 4 EC (chlorpyrifos)	0.75-1	1.5-2 pt	5.3-4	14-graze,silage; 35-grain, fodder
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row
Mocap EC (ethoprop)		1.4 oz/1000 ft row		Apply at planting.
Mocap 10 G (ethoprop)		10.5 oz/1000 ft row		Apply at planting.
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30-grain or fodder
Sevin 80S (carbaryl)	1.8	2.5 lb	0.4	48-grain, fodder; 14-forage,silage
Sevin XLR Plus (carbaryl)	2	2 qt	2	48-grain, fodder; 14-forage,silage
Warrior Z (lambda cyhalothrin)	0.015-0.025	1.92-3.20 oz	66.7-40	21
EUROPEAN CORN BORERS
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30-grain or fodder
Asana XL (esfenvalerate)	0.04-0.05	7.8-9.6 oz	16-13	21
Bacillus thuringiensis	See individual brand labels.
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45
Capture 1.15G (bifenthrin)	0.04-0.10	3.5-8.7 lb		30 Broadcast directing granules into whorl.
Furadan 4F (carbofuran) *See Carbofuran Note	0.75-1	1.5-2 pt	5.3-4	30
Lorsban 15 G (chlorpyrifos)	6-8 oz/1000 ft row (post plant)
Lorsban 4 EC (chlorpyrifos)	0.75-1	1.5-2 pt	5.3-4	14-graze,silage; 35-grain, fodder
Penncap-M (methyl parathion)	0.5-1.0	2-4 pt	4-2	12 Do not apply if bees are forageing in area to be treated.
Phorate 20 G (phorate)	1	5 lb	0.2	30-graze, forage; apply to whorl
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30-grain or fodder
Sevin XLR Plus (carbaryl)	1.5-2	1.5-2 qt	2.7-2	48-grain, fodder; 14-forage, silage
Sevin 80S (carbaryl)	1.5-2	1.87-2.5 lb	0.53-0.4	48-grain, fodder; 14-forage, silage
Tracer 4 (spinosad)	0.031-0.094	1-3 oz	128-43	28-grain, fodder;7-forage
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
FALL ARMYWORMS
Baythroid 2 (cyfluthrin)	0.044	2.8 oz	45	21; 0-for green forage
Capture 1.15G (bifenthrin)	0.04-0.10	3.5-8.7 lb		30 Broadcast directing granules into whorl.
Lannate 2.4 LV (methomyl)	0.23-0.45	0.75-1.5 pt	10.7-5.3	21-fodder, ears; 3-forage
Methyl 4 EC (methyl parathion)	0.25	0.5 pt	16	12 Do not apply during pollen shed.
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
Tracer 4 (spinosad)	0.031-0.094	1-3 oz	129-43	28-grain, fodder;7-forage
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
FIRE ANTS
Force 3G (chlorpyrifos)		4-5 oz/1000 ft row		Apply at planting. For suppression only.
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		14-silage, forage; 35-grain, fodder Banded at planting. For suppression only.
FLEA BEETLES
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30-grain or fodder
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Counter CR (terbufos)		6 oz/1000 ft row		30-apply at planting
Lannate 2.4 LV (methomyl)	0.23-0.45	0.75-1.5pt	10.7-5.3	21-fodder, ears; 3-forage
Lannate SP 90% (methomyl)	0.22-0.45	0.25-0.5 lb	4-2	3-forage
Lorsban 15 G (chlorpyrifos)	2	13.5 lb (PPI-larvae)	0.074	14-silage, forage; 35-grain, fodder
Lorsban 4 EC (chlorpyrifos)	0.75-1	1.5-2 pt	5.3-4	14-graze,silage; 35-grain, fodder
Penncap-M (methyl parathion)	0.5-0.75	2-3 pt	4-2.7	12 Do not apply if bees are foraging in area to be treated.
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30-grain or fodder
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
GRASSHOPPERS
Asana XL 0.66 EC (esfenvalerate)	0.03-0.05	5.8-9.6 oz	22-13	21
Baythroid 2 (cyfluthrin)	0.033-0.044	2.1 -2.8 oz	61-45	21; 0-for green forage
Dimethoate 4 EC (dimethoate)	0.5	1 pt	8	14
Furadan 4F (carbofuran) *See Carbofuran Note	0.125-0.25	0.25-0.5 pt	32-16	30
Lorsban 4 E (chlorpyrifos)	0.25-0.5	0.5-1 pt	16-8	14-silage; 35-grain,fodder
Methyl 4 EC (methyl parathion)	0.5	1.0 pt	8	12 Do not apply during pollen shed.
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
LEAFHOPPERS
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
LESSER CORNSTALK BORERS
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
Force 3G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting.
Lorsban 4 EC (chlorpyrifos)	1	2 pt	4	14-graze,silage; 35-grain, fodder
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		14-silage, forage; 35-grain, fodder Band at planting;
MAIZE BILLBUGS (Also called: Corn Billbugs, Billbugs, Southern Corn Billbugs)
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting or post emergence.
Force 3 G (terbufos)		4-5 oz/1000 ft row		Apply at planting. For suppression only.
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		14-silage, forage;35-grain, fodder Banded at planting time.
Lorsban 4 E (chlorpyrifos)	2	4 pt (PPI)	2	14-silage, forage; 35-grain, fodder
Lorsban 4 EC (chlorpyrifos)	1	2 pt	4	14-graze,silage; 35-grain, fodder
MITES
Comite 6 E (propargite)	1.6-2.5	2-3 pt	4-2.7	30 Apply when corn leaves are dry. For two-spotted spider mite.
Dimethoate 4 EC (dimethoate)	0.33-0.5	2/3-1 pt	12-8	14 For Banks grass mite and two-spotted spider mite.
Furadan 4 F (carbofuran) *See Carbofuran Note	1	2 pt	4	30 For suppression only.
Microthiol Disperss (sulfur)	6.4-8	8-10 lb	0.125-0.1	0 For Banks grass mite.
Phorate 20 G (phorate)		6 oz/1000 ft row	21.3	30 Apply at planting.
PICNIC BEETLES
Lannate 2.4 LV (methomyl)	0.23-0.45	3/4-1 1/2 pt	10.7-5.3	21-fodder, ear; 3-forage
SAP BEETLES
Sevin XLR Plus (carbaryl)	1-2	1-2 qt	8-4	48-grain, fodder; 14-grain, silage
Sevin 80S (carbaryl)	1-2	1.25-2.5 lb	0.8-0.4	48-grain, fodder; 14-grain, silage
SEED CORN BEETLES
Capture 1.15G (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row		30 Band over open seed furrow at planting. Must be incorporated.
Capture 2 EC (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row		30 Apply in seed furrow. Must be incorporated.
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting.
Lorsban 4 E (chlorpyrifos)	2	4 pt (PPI)	2	14-silage, forage; 35-grain, fodder
SEED CORN MAGGOTS
Capture 15G (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row		30 Band over open seed furrow at planting. Must be incorporated.
Capture 2 EC (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row		30 Apply in seed furrow. Must be incorporated.
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting.
Fortress 5 G (chlorethoxyfos)		3-3.75 oz/1000 ft row		Apply at planting.
Lorsban 4 E (chlorpyrifos)	2	4 pt (PPI)	2	14-silage, forage; 35-grain, fodder.
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		Banded at planting.
STALK BORERS
Ambush (permethrin)	0.1-0.2	6.4-12.8 oz	20-10	0-forage; 30 grain or fodder
Asana XL (esfenvalerate)	0.03-0.49	5.8-9.6 oz	22.1-13.3	21
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Lorsban 4 EC (chlorpyrifos)	1	2 pt	4	14-graze,silage; 35-grain, fodder
Pounce 3.2 EC (permethrin)	0.1-0.2	4-8 oz	32-16	0-forage; 30 grain or fodder
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
STINK BUGS
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Methyl 4 EC (methyl parathion)	0.25	0.5 pt	16	12 Do not apply during pollen shed.
SYMPHYLANS
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
Fortress 5 G (chlorethoxyfos)		3-3.75 oz/1000 ft row		Apply in furrow at planting.
Lorsban 4 E (chlorpyrifos)	1-2	2-4 pt (PPI)	4-2	14-silage, forage; 35-grain, fodder.
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		14-silage, forage; 35-grain, fodder.
Mocap EC (ethoprop)		1.4 oz/1000 ft row		Apply at planting.
Mocap 10 G (ethoprop)		10.5 oz/1000 ft row		Apply at planting.
THRIPS
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
WEBWORMS
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Lorsban 4 E (chlorpyrifos)	0.5-1	1-2 pt	8-4	14-silage, forage; 35-grain, fodder
Warrior Z (lambda cyhalothrin)	0.02-0.03	2.56-3.84 oz	50-33.3	21
WHITE GRUBS
Baythroid 2 (cyfluthrin)	0.025-0.044	1.6-2.8 oz	80-45	21; 0-for green forage
Capture 1.15G (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row		30 Band over open seed furrow at planting. Must be incorporated.
Capture 2 EC (bifenthrin)	0.005-0.006	6.4-8 oz 1000 ft row		30 Apply in seed furrow. Must be incorporated.
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting.
Fortress 5 G (chlorethoxyfos)		3-3.75 oz/1000 ft row		Apply in furrow at planting.
Lorsban 4 E (chlorpyrifos)	2	4 pt (PPI)	2	14-silage, forage; 35-grain, fodder.
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		14-silage, forage; 35-grain, fodder.
Mocap EC (ethoprop)		1.4 oz/1000 ft row		Apply at planting. For suppression only.
Mocap 10 G (ethoprop)		10.5 oz/1000 ft row		Apply at planting. For suppression only.
Phorate 20 G (phorate)		6 oz/1000 ft row
WIREWORMS
Capture 1.15G (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row		30 Band over open seed furrow at planting. Must be incorporated.
Capture 2 EC (bifenthrin)	0.005-0.006	6.4-8 oz/1000 ft row	0.1-0.19	30 Apply in seed furrow Must be incorporated.
Counter CR (terbufos)		4.5-6 oz/1000 ft row		30 Apply at planting.
Force 3 G (tefluthrin)		4-5 oz/1000 ft row		Apply at planting.
Fortress 5 G (chlorethoxyfos)		3-3.75 oz/1000 ft row		Apply in furrow at planting.
Lorsban 4 E (chlorpyrifos)	2	4 pt (PPI)	2	14-silage, forage; 35-grain, fodder
Lorsban 15 G (chlorpyrifos)		8 oz/1000 ft row		14-silage, forage; 35-grain, fodder
Mocap EC (ethoprop)		1.4 oz/1000 ft row		Apply at planting.
Mocap 10 G (ethoprop)		10.5 oz/1000 ft row		Apply at planting.
Phorate 20 G (phorate)		6 oz/1000 ft row		30 Apply at planting.

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Footnotes

1. This document is ENY401 (IG060), one of a series of the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date: October, 1993. Revised: December 2005. Visit the EDIS Web Site at http://edis.ifas.ufl.edu.

2. Richard Sprenkel, professor, Department of Entomology, North Florida Research and Education Center--Quincy; Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, 32611.

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Copyright Information

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