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Types of insect control can be categorised into

• Cultural
• Mechanical/Physical
• Biological
• Genetic
• Chemical

Cultural

This includes the use of various farm practices which directly or indirectly reduce pest populations. e.g. crop rotation, ploughing, planting time, pruning, thinning etc.

Mechanical/Physical

This includes the simple fly swat, fly screen and mosquito nets, light traps ('zappers'), exclusion methods such as packaging and sealing (e.g.  against storage pests), sifting and separation in flour mills and the use of temperature, humidity and gas regimes against storage and museum pests. It also includes drainage against mosquitoes and removal of bushes against tse tse flies (q.v.)

Biological

This includes the application of available predators, parasites or diseases, either natural, introduced or commercially available.

e.g. Introduction of Australian ladybirds to USA citrus, spray applications of bacterial diseases against caterpillars.

Genetic

This includes male sterilisation techniques, selective breeding and genetic modification.

Male sterilisation techniques involve the mass rearing of a pest, laboratory sterilisation of males and their release into the wild with the purpose of swamping the wild male population leading to infertile egg laying. For this strategy to work, the females need to mate only once and not to be able to select against the sterile males.

This method worked extremely well with screw worm, leading to its complete eradication in USA (see specific pests).  However, the same method did not work on sheep blow fly in Australia (which see) as the females selected against the sterilised males.

Chemical

Chemical control includes both behaviour modifiers and insecticides.

Behaviour modifiers

1. Attractants - cause insects to move towards their source
   1. Pheromones - secreted by insect, species specific - may be used to lay trails, or for aggregation, swarming, alarm or sexual attraction.
   2. Food and oviposition attractants. E.g. Qld fruit fly is attracted to NH_{3 ,} flavouring essences and protein sources
2. Antifeedants - prevent an insect from feeding and it starves
3. Antioviposition chemicals - females won't lay eggs.
4. Repellents - e.g. personal fly repellents

USE OF ATTRACTANTS

1. Monitoring of pest situation.
   Traps give an early warning system in quarantine situations and are used in crops to monitor pest intensity to indicate when to apply insecticides e.g. coddling moth control.
2. Direct control
   • When baits are combined with a lethal trap or insecticide -> direct kill  e.g. dark pots against fruit fly in orchards.
   • Mating disruption occurs when the environment is saturated with mating pheromone so that the male is confused and cannot find a mate. (used in control of oriental fruit moth).

LIMITATIONS OF ATTRACTANTS

Development of workable pheromone mixtures, traps and application methods is time consuming and costly. It requires -

1. Knowledge of physiology of pest for design of traps - size, shape, material, trap opening, the density of traps required and their positional placement in the crop.
2. Development of a substrate which will release the pheromone in a controlled, consistent rate.
3. Knowledge of the active ingredients in a pheromone - the optimal concentration of each component and whether this changes over time.
4. Financial investment - These chemicals also need to be registered, requiring lots of data. Since these cannot be patented, there is little money to be made from their commercial development and so it is usually left to government agencies.

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