Expanded Corn Insect Pest Info
This document is intended to help consultants and producers make preliminary decisions about insect management options. The information in this publication is thought to be correct at the time of writing, however labels frequently change without much warning. It is impossible to include all of the usage, safety and precautionary statements for any given product in this type of publication. Users should check labels carefully before applying to ensure the product(s) under consideration can and will be applied legally. Remember that contamination of the treated crop or commodity can occur through illegal use. K-State entomologists assume no responsibility for product performance, personal injury, property damage, or other types of loss resulting from the purchase, handling or use of the pesticides listed.
Except where indicated, the insecticides listed are intended for use on field corn. (Producers should check current labels before treating popcorn, seed corn, silage or other types of corn to verify that the insecticide is labeled for that crop and purpose.) The first word(s) refer to the common chemical name of the active ingredient, followed in parentheses by the most commonly used trade name(s).
Occasionally, specific formulations are listed for a particular use. The mention of commercial products does not imply approval to the exclusion of other similar products. The economics associated with achieving control should be considered in any pest management decision. However, because costs vary greatly over time and among sources and are influenced by factors beyond the scope of this publication, product cost, in general, was not considered a reason for either including or omitting specific insecticides from these recommendations. We recommend that producers compare price, safety and availability of products.
The preharvest interval (PHI) refers to the time that must elapse between application and harvest. The interval is often different for forage use than grain harvest. Waiting intervals must still be followed even when use of the commodity is not specified. The waiting interval does not signify how long an insecticide will provide control following application.
The restricted entry interval (REI) specifies the time that must elapse before people can safely return to work in treated fields without the use of protective clothing and (or) equipment. Look for this information within the agricultural use requirements section of the label.
A number of insecticides are classified as restricted use pesticides. Individuals (private or commercial) must be certified by the Kansas Department of Agriculture before purchasing or using restricted use products. Some pesticide uses may be permitted by means of State of Kansas Special Local Needs (SLN) labels. The law requires users to possess this label before applying a SLN product.
As with all pesticides, the user bears responsibility for correct use. If there is any question about the intended use, contact the manufacturer of the product, K-State Research and Extension, or the Kansas Department of Agriculture before applying. Always read and follow label directions carefully. Never use a pesticide when the validity of the label or the intended use is in doubt.
Soil Insects and Crop-Management
Planting-time corn insect management in Kansas is concerned with evaluating the damage potential of one or more insect species that spend at least a portion of the damaging stage within the soil profile. Effective sampling of populations may be impractical, so decisions often must be made without knowing how serious a threat any given species may be on a field-by-field basis. In addition to masking populations, the soil serves as a protective blanket for the insects. This means that correcting a below ground problem that has developed to economically damaging proportions with a “rescue treatment” is seldom possible (with the exception of black cutworm infestations).
Understanding why the problem develops depends upon an adequate knowledge of both biology and ecology of the pest and crop. For instance, some problems only develop or are antagonized by specific rotations. Corn rootworms became a major pest once the availability of relatively cheap forms of nitrogen fertilizer made continuous corn possible. In comparison, rootworm larval damage is seldom a problem in Kansas if corn is rotated with another crop each year.
Corn rootworm beetles lay most of their eggs in corn fields from late summer through early fall. The larvae of the corn rootworm feed almost exclusively on the roots of corn (field corn, popcorn or sweet corn). By planting corn in a field every other year, growers avoid the expense of a planting-time corn rootworm insecticide.
In continuous corn production, corn rootworm planting-time insecticides typi¬cally have been used as insurance against economic damage that otherwise might be inflicted on the current corn crop. However, simply because a field has been in continuous corn production, corn rootworm insecticides are NOT mandatory. This publication is designed to help producers identify where the risk of damage is low enough that treatment should not be necessary. In particular, corn rootworm adult scouting techniques have proven very useful in establishing the potential for damaging rootworm larval populations the next year.
Product Placement
Equipment Calibration and Maintenance
This is an area producers frequently overlook. Remember that when changing products, applicators should be recalibrated. Two 15G products (15 percent active ingredients, 85 percent inactive carrier such as a clay or corn-cob grits) may look very much alike but often have very different flow rates.
A potentially more serious oversight develops when changing from one concentration of active ingredient to another. Changing from a 10G product (10 percent active ingredient) to a 20G product (twice as concentrated at 20 percent active ingredient) or vice versa can cause severe problems resulting from too much or too little product applied. Crop damage or inadequate protection can result in addition to unnecessary expense, illegal pesticide residues, and violating the label requirements, which carry the force of federal and state law.
Normal wear also can alter the output of an applicator over time. The frequency of recalibration varies with the individual situation and level of use, but in all instances, recalibration should be performed on at least annually. One study found that more than half of planters surveyed had at least one insecticide applicator delivering 20 percent more or less insecticide than ideal.
A Word About Seed Treatments
Seed treatment insecticides can be categorized into two major groups: contact seed treatments (diazinon, lindane and permethrin) and systemic seed treatments. A contact insecticide, usually applied as a planter box application, is used to control insects that come in contact with or feed on the planted seed. This type exhibits no action against pests feeding on other plant parts.
Systemic seed treatments (clothianidin, fipronil, imidacloprid and thiamethoxam) are applied by commercial seed-treating establishments to protect against damage caused by most seed attacking insects and some soil insects. They also work systemically to provide early season protection against certain aboveground early season foliage feeding insect pests. Check with local seed suppliers to determine the availability of these products on hybrids in question.
Using Insecticides Safely
Injury or death can result from swallowing, inhaling or prolonged skin contact with insecticides. The risk of injury from ingestion is greatest among pets, livestock and young children. Skin absorption and sometimes inhalation usually pose the greatest risk to users. Handle all pesticides with care and use them only when needed. Avoid spilling concentrates on the skin or clothing.
If a spill occurs, remove contaminated clothing immediately, and wash with soap and water. If in the eyes, flush with water for 15 minutes and seek prompt medical attention. If exposed and in need of medical treatment, take the pesticide label with you. For poison control information call 800-332-6633 or the new nationwide number 800-222-1222.
Wear protective equipment (respirators, clothing, etc.) as specified on the label. Bathe and change clothing frequently. Launder contaminated clothing separately.
Protect fish, wildlife and other nontarget organisms. Do not dispose of unused pesticides where the runoff may contaminate streams, lakes, or drinking water supplies, nor apply in a manner that could pollute such sites.
Consider the presence of honeybees before applying insecticides. Application to blooming-stage legumes can usually be avoided. Avoid drift to beehives or adjacent blooming crops. Notify the bee owner before applications are made in the general vicinity. Applying treatment late in the day when bees are not foraging may help to reduce the risk.
Read the label carefully. It is a legal document. It tells what, where, how and when the product can be used.
Worker Protection Standard
The Worker Protection Standard (WPS) is a series of federal regulations pertaining to pesticides used in agricultural plant production on farms, forests, nurseries, and greenhouses. You must comply with these regulations if you are an agricultural pesticide user and/or an employer of agricultural workers or pesticide handlers. For details, consult the U.S. Environmental Protection Agency publication, The Worker Protection Standard for Agricultural Pesticides—How to Comply, What Employers Need to Know. This publication is available at your local K-State Research and Extension office.
Insecticide Safety
Injury or death can result from swallowing, inhaling or prolonged skin contact with insecticides. The risk of injury following ingestion is greatest among pets, livestock and young children. The greatest risk among users usually results from skin absorption, and sometimes inhalation. Practice handling all pesticides with care and use them only when needed. Wear protective equipment (respirators, clothing, etc.) as specified on the label. Bathe and change clothing frequently. Launder contaminated clothing separately from other articles in the wash. Avoid spilling concentrates on the skin or clothing. If a spill occurs, remove contaminated clothing immediately and wash with soap and water. If material gets into the eyes, flush them with clean water for 15 minutes and seek prompt medical attention. If exposed and in need of medical treatment, take the pesticide label with you.
In Case of Emergency
For poison control information call the Mid-America Poison Control Center, University of Kansas Medical Center, 39th & Rainbow Blvd., Kansas City, KS. 66103, 800-332-6633 or 913-588-6633. There is also a new nationwide number: 800-222-1222.
Protect fish, wildlife and other non-target organisms. Do not dispose of unused pesticides where the runoff may contaminate streams, lakes, ponds or drinking water supplies, or apply in a manner that could pollute such sites. Consider the presence of honeybees before applying insecticides. Avoid drift to beehives or adjacent blooming crops. Notify bee owners before applications are made in the general vicinity. Applying treatment late in the day when bees are not foraging may help reduce the risk.
Read the label carefully. It is a legal document. It tells what, where, how and when the product can be used. It is against the law to use a pesticide in a manner inconsistent with the label.
Page last updated 11/05/2013 by J.P. Michaud.