Key Terms

IPM: Integrated pest management. Integrated pest management (IPM) is an ecosystem-based strategy that focuses on long-term prevention of pests or their damage through a combination of techniques such as biological control, habitat manipulation, modification of cultural practices, and use of resistant varieties. Pesticides are used only after monitoring indicates they are needed according to established guidelines, and treatments are made with the goal of removing only the target organism. Pest control materials are selected and applied in a manner that minimizes risks to human health, beneficial and nontarget organisms, and the environment. Source: University of California IPM Program

Economic threshold (ET): The number of arthropods (per sample) at which action should be taken to avoid experiencing monetary loss or reaching the economic injury level.

Economic injury level (EIL): The number of arthropods (per sample) at which action should be taken to avoid experiencing monetary loss or reaching the economic injury level.

The number of arthropods whose resulting injury is greater than the cost to manage them.  The EIL is most commonly expressed as EIL = C/(VIDK) where:

C = cost of insect control

V = value of a unit of the crop?(ie. lb cured leaf)

I = injury units per insect

D = damage (proportion of yield lost) per injury unit

K = proportionate reduction in injury (efficacy of the selected control)

Sample: Sampling methods vary depending on the crop.  The economic thresholds in tobacco are based on a sample of10 stops in a small field (10 acres or less).  In larger fields, add two stops for each additional 4 acres or split the field into smaller areas and make a separate decision for each area. Five (5) plants are examined at each stop, and all insects and insect damage are counted.  Stops should be randomly distributed throughout the field and not concentrated near borders.  Pests are often much more numerous on field margins, and some may justify border treatments. Determine stops before entering the field to avoid basis.

Monitoring: Sampling over time.  Tobacco fields should be sampled at least biweekly, ideally weekly.  Data should be recorded to allow for comparison between samples.OMRI:The Organic Materials Registry Institute.  Agrochemicals (fertilizers, fungicides, herbicides, insecticides, and other materials) must be approved by OMRI in order to be used in USDA certified organic production.

North Carolina Agricultural Chemicals Manual: An annually updated compendium of the pesticides registered and recommended for use on agricultural crops in North Carolina.  This publication can be found online here.

Polyphagous: Refers to insects whose diets include many potential hosts that are not closely related (ie. an insect that feeds on cotton and tobacco).

Oligophagous: Refers to insects whose diets include hosts of more than one species but these species are closely related (ie. an insect which feeds on tomato and tobacco).

Monophagous: Refers to an insect which feeds only on 1 species.

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