Managing Insect PestOutbreaks

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Managing Insect PestOutbreaks

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There are over one million known species of insects and most of them cause no harm to humans and the environment. Many insects are classified as important to our existence and provide environmental benefits such as pollination of plants and aeration of soils.However, some insects are classified as pests.

There are insects of public health importance, some that cause wood and structural damage, and some which are nuisance pests. A very small percentage of insects are considered to be economically important pests. This class of insect pests,specifically related to agriculture, causes billions of dollars of losses annually to the US economy.

In agriculture, insect pests damage crops by attacking seeds, chewing plant foliage, sucking sap, boring, and tunneling in stems and branches, and transmitting diseases. Further damage can occur when crops are harvested and stored because they are subject to damage by storage insect pests.Insect pest outbreaks are common in agriculture.

What is an Insect Pest Outbreak?

An insect pest outbreak is a large and sporadic population of insect pests. They occur when the pest population rises significantly above its general equilibrium level and becomes a threat to human interests and endeavors. Four common scenarios lead to insect pest outbreaks:

  1. Environmental change – Insect populations have a large gene pool and a high reproductive rate which allows them to adapt and exploit changing conditions in the natural environment. Changes in climate, habitat, or community structure may provide an insect population with a reproductive opportunity that enables a rapid increase in population. Monoculture cultivation of crops and housing of livestock in modern rearing facilities are common practices in the US that lead to periodic insect outbreaks.
  2. Introduction from abroad – International travel and trade is an opportunity for the spread of insects from one part of the world to another. In their new niche, the insects will take the absence of parasites and predators as an opportunity to increase their population and outcompete or displace native insects.
  3. Destruction of natural enemies – Pest populations can reach outbreak levels if their parasites and predators are suppressed or eradicated. When pesticides are used to control a pest population, they may kill or repel beneficial insects. Thereafter, when the effects of the pesticide wear off, a resurgence in the pest population may lead to an insect outbreak.
  4. Development of resistance – Insect pests can develop resistance to the control tactic being used, which is usually insecticide. Unless the control tactic is varied, the insect population may reach outbreak proportions quickly.

How can an insect outbreakbe prevented?

An orderly process of decision-makingmust be used when devising insect control plans, especially when attempting to manage a new and unfamiliar insect problem. The steps are:

  1. Detection – Keeping a watchful eye for insects that are likely to be troublesome is an important first step. Early detection of an insect infestation helps prevent irreparable damage before it is too late.
  2. Identification – Accurate identification of an insect is necessary for control measures to be effective. Misidentification may impair control and lead to an insect outbreak.
  3. Biology and habits – Knowledge of seasonal life cycle attributes of an insect pest within a habitat is important to pinpoint the most effective time for treatment. By understanding the biology of the insect pest, the insect’s life cycle’s most vulnerable stages can be determined which will help direct the control effort to obtain the most effective and economical control.
  4. Economic significance – Before control efforts are initiated, a reasonable determination must be made whether it is necessary to control the targeted insect pest. There needs to be a return on the investment in controlling the insect pest.
  5. Selection of control method – The proper method or combination of methods should be selected to provide effective, practical, economical, and safe control of the insect pest. Control methods include:
    • Cultural control – e.g., use of crop rotation, tillage methods, and resistant or tolerant varieties.
    • Mechanical control – e.g., use of screens, traps, light, and sound.
    • Biological control – e.g., use of parasites, predators, diseases, male sterility, temperature, and moisture.
    • Chemical – e.g., use of insecticides and other chemical compounds that kill, repel, attract, and disrupt the growth and development of insects.
    • Integrated control – using a combination of all possible compatible techniques to manage insect populations at subeconomic levels, e.g. using an artificial or natural biological method in combination with a selective chemical and cultural control method.
  6. Application – The control methods selected must be applied appropriately and timely to be effective and safe. If chemicals are applied, the applicator must read and follow the instructions on the labels ofall chemicals used. Applying insecticide with an adjuvant to increase control efficacy. For example:
    • SilEnergy nonionic wetting and penetrating surfactant may be included in the pesticide spray mixture to improve insect control. SilEnergyhelps to decrease surface tension resulting in better coverage and increased pesticide absorption into the plant.
  7. Evaluation–An important step in insect control is determining whether the control operation was successful. This can be accomplished by making comparisons of before and after treatments were applied. For example, using insect counts and comparative damage ratings.
  8. Recording–A record of insect management provides a basis to gain from past experiences.

If the insect pest is well-known, some of the preceding steps can be skipped.

Managing insect outbreaks requires proper planning and control of insect pests once they are detected and properly identified.


Brewer International has been a leader in land and water chemistry since the 1980s and for over 40 years has proudly served its national and regional distributors.

Our products are used widely across the United States in agriculture, aquatics, forestry, rights of way, and land management.

Our customers trust our dedication to quality ingredients, tried and true formulas, and positive outcomes.

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