Apply cultural and biological control practices whenever possible to prevent pest populations from reaching damaging levels. In many situations, cultural practices, such as crop rotation, resistant cultivars, tillage and fertility management, and early harvest, can reduce the intensity of pest attack and also increase the crop's ability to withstand insect feeding. Parasites, predators, and disease pathogens are natural enemies of insect pests, which are present in virtually every field situation. A number of parasitic species have been imported, released, and established in Maryland and other Mid-Atlantic states to control some of the major insect pests. Some species have been successful in establishing repeating generations, some have to be re-released annually, and others have not been successful. USDA-APHIS, along with several cooperating states, is working toward developing new parasite species that may someday further the biological control effort. The goal of any management program is to maximize the impact of these local and introduced natural enemies and avoid applications of disruptive insecticides unless they are absolutely necessary. Keep in mind that low population levels of host insects are required to maintain these beneficial organisms. Simply stated: no food, no beneficials. In this section, major cultural and biological control methods are described for individual pests and marked with this special symbol:
1.Accurately identify the pest. A prerequisite to all pest management decisionmaking is correct identification of the problem. Often, damage is evident in a field but no insect pest can be found. Learn to recognize the symptoms of insect feeding to identify the problem if the insect is not present. Consult a crop advisor or your county Extension educator for help if you have questions.
2.Understand the pest and crop dynamics to properly evaluate the consequences of the situation. Decisionmaking guidelines are provided in this section for most insect pests. They include information regarding the biology of the pest, its potential risk to the crop, and the best management strategy. The best strategy often differs from one pest species to another and among fields.
3.Monitor to detect a problem before damage reaches an advanced stage. Frequent and regular field inspections must be conducted to determine the density and development of insect pest populations. Sampling information is given in this section for each insect pest. If growers do not have the time to regularly monitor their crops, they can hire a professional scout or certified crop advisor. Contact your county Extension educator for information on the availability of pest management services and for information regarding where to obtain special sampling equipment, such as sweep nets and shake cloths.
4.Another way to monitor the adult stage (moth) of certain insect populations is with black light traps and pheromone traps. These devices are used to determine when an insect pest becomes active, when to start looking for the insect in the field, and whether there is enough moth activity to cause economic problems. To get specific moth activity information in Maryland, call toll-free the following data phones, which are updated twice weekly during the growing season by the Maryland Department of Agriculture. For data relating to the Eastern Shore and southern Maryland, call 800-492-2105; for information relating to central and western Maryland, call 800-492-2106. For Delaware trap data, call 302-451-8851 for weekly updates of average daily catches of corn borer and corn earworm.
4.Apply control measures only if the insect population level exceeds the treatment threshold. Do not apply controls simply because a neighbor does or there is a reported threat of a pending pest outbreak. Populations of most insect pests vary widely from field to field. The most basic concept in pest management is that control action is not justified unless the expected losses exceed the cost of control. The decisionmaking guidelines in this section include treatment thresholds that help growers decide if insecticide applications or other management actions are needed to avoid economic loss. Treatment thresholds are generally expressed as a numerical count of a given insect stage or as a damage level based on a recommended sampling procedure. A threshold is only a guide or starting point that approximates the population density that will cause economic injury if left uncontrolled. It is not written in stone. Control decisions also are based on the field history, presence of natural enemies, crop stage and vigor, cultivar, weather conditions, and other factors. Growers may have to adjust thresholds to fit their specific field situations.
5.If an insecticide treatment is required, apply the right material at the proper time with the appropriate application method. Often, failure to control an insect or mite pest is blamed on the product when the cause lies elsewhere. The most common reasons for control failures include improper timing of applications (usually applied late when the pests are too large or numerous); making applications with an insufficient volume of diluted spray (commonly occurs with aerial application during hot, dry conditions); clogged or poorly arranged nozzles or granular distributors; high pH and/or mineral content of the spray water, which can rapidly degrade most chemicals; and selecting the wrong insecticide.
6.Follow up all pest control actions to evaluate results. Evaluation is often omitted on the assumption that the treatment has done its job. This step is necessary to determine whether the insecticide or nonchemical measure has suppressed the pest population enough to prevent economic loss. It also provides information regarding the need for additional control actions and ways that the control actions can be fine-tuned to make them more suitable for the particular field situation.
7.Sampling and decisionmaking guidelines and information about current pest activity are provided in weekly IPM newsletters and reports, Extension leaflets and fact sheets, telephone recordings, radio talks, newspapers, and websites. These publications and information sources furnish more up-to-date facts on insect occurrence, the need for and timing of insecticide applications, and suggestions for more effective control. Contact your county Extension educator or state pest management specialist if you want to receive IPM information. Access pest and crop management information directly at the PestNet website at http://www.mdipm.umd.edu/ and at the Delaware Weekly Crop Update website at http://www.udel.edu/IPM/. For Virginia data on corn earworm, consult the Virginia Corn Earworm Advisory at any local Extension office for weekly updates, or call 757-657-6450, ext. 126, or check the IPM website at http://IPM-WWW.ento.vt.edu:8000/nipmn/VA-IPM/updates.html.
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