7.5 The Six Pest Control Methods
Key Takeaways
- The six control methods are biological, chemical, cultural, genetic, mechanical or physical, and regulatory - integrated pest management combines them rather than choosing one.
- Biological control uses natural enemies - predators, parasitoids and pathogens - through conservation, augmentation or classical importation, and is the method most easily destroyed by unnecessary broad-spectrum insecticide applications.
- Cultural control changes the crop system so the pest is less favoured: rotation, planting date, tillage, sanitation, resistant varieties, row spacing, irrigation timing and destruction of crop residue.
- Genetic control includes resistant varieties, herbicide- and insect-tolerant traits, and sterile insect techniques; the trait is only durable if it is managed against resistance.
- Regulatory control is government action - quarantine, inspection, certification and eradication programs - and is the reason Arkansas licenses a regulatory pest control category.
7.5 The Six Pest Control Methods
Core Concept: Integrated pest management is not "use less pesticide." It is the deliberate combination of six control methods so that the chemical component is used where it is genuinely the best tool, at a time when it will work. An applicator who understands only chemical control is limited to one move.
1. Biological Control
Using natural enemies to suppress pest populations.
| Enemy type | How it works | Examples |
|---|---|---|
| Predators | Consume many prey over a lifetime | Lady beetles, lacewings, minute pirate bugs, predatory mites, spiders, ground beetles |
| Parasitoids | Lay eggs in or on a host; the developing larva kills it | Braconid and ichneumonid wasps, Trichogramma egg parasitoids, tachinid flies |
| Pathogens | Infect and kill the pest | Bacillus thuringiensis (Bt), entomopathogenic fungi such as Beauveria, nematodes, viruses |
Three deployment strategies:
- Conservation - protect the natural enemies already present. This is the cheapest and most important strategy, and it is exactly what an unnecessary broad-spectrum insecticide destroys. Secondary pest outbreaks and pest resurgence are the direct consequence.
- Augmentation - release additional natural enemies, either inoculative (small releases early) or inundative (mass release for immediate effect).
- Classical or importation - import and establish a natural enemy from the pest's native range, usually against an introduced pest, after extensive host-specificity screening.
Selectivity matters: choosing a narrow-spectrum or selective product, or an application timing that misses the natural-enemy window, preserves biological control while still hitting the target.
2. Chemical Control
Pesticides. Fast, flexible, and often the only option once a population exceeds the economic threshold. Its costs - resistance selection, non-target effects, drift and residue liability, worker exposure, cost per acre - are exactly why the other five methods exist. Chemical control belongs in the program when scouting shows the threshold has been reached and the other tools cannot act fast enough.
3. Cultural Control
Changing how the crop is grown so the environment is less favourable to the pest. In Arkansas row-crop systems this is where most of the durable gains live.
- Crop rotation - breaks host-specific pest and pathogen cycles and is central to nematode and soilborne disease management.
- Planting date - early or delayed planting can move the susceptible crop stage out of phase with peak pest pressure.
- Sanitation - destroy crop residue, control volunteers and weedy hosts on field margins, clean equipment between fields to avoid moving weed seed and soilborne pathogens.
- Tillage - buries residue and disrupts overwintering; note that tillage fragments and spreads creeping perennial weeds rather than controlling them.
- Water management - irrigation timing and drainage change disease pressure directly; in rice, flood depth and timing are themselves pest management tools.
- Row spacing and plant population - canopy closure suppresses late weed flushes but can raise humidity and disease pressure, so the two must be balanced.
- Fertility - a vigorous crop competes and tolerates injury better; excess nitrogen can increase susceptibility to some diseases and insects.
- Trap crops and border management - concentrate the pest where it can be treated on a small area.
4. Genetic Control
- Resistant or tolerant varieties - the highest-value, lowest-cost tool available, and one leg of the disease triangle removed outright.
- Transgenic traits - insect-protected (Bt) and herbicide-tolerant crops. Both require resistance management: structured refuges for Bt, and mode-of-action rotation and diversity for herbicide tolerance. Arkansas's Class H and Enlist rules are the regulatory face of this - herbicide-tolerant technology brought both weed control and a new drift problem.
- Sterile insect technique - mass-rear, sterilize and release males so matings produce no offspring, driving the population down over generations. Used historically in area-wide eradication programs.
5. Mechanical and Physical Control
- Exclusion - screens, barriers, row covers, door sweeps, caulking, pipe collars, fencing against deer and hogs.
- Trapping - both for monitoring (pheromone and sticky traps drive threshold decisions) and for control.
- Cultivation and hand removal - mechanical weed control, still the backstop against herbicide-resistant Palmer amaranth escapes.
- Physical environment manipulation - temperature (heat treatment, cold storage), humidity control, light traps, flooding, mowing.
6. Regulatory Control
Government action to prevent introduction and spread.
- Quarantines restricting movement of plants, soil, or equipment out of infested areas.
- Inspection and certification of nursery stock, seed and produce.
- Eradication and survey programs - the boll weevil eradication program is the Mid-South's landmark example.
- Restricted use classification and state class designations - Arkansas's Classes A through J are themselves a regulatory control.
This is why regulatory pest control is one of the Arkansas commercial applicator categories, and why regulatory pest control applicators are exempt from the financial responsibility requirement in 2 CAR Sec. 72-102(e).
Fitting Them Together
A worked Arkansas soybean example against Palmer amaranth:
- Cultural - narrow rows for faster canopy closure, a cover crop for suppression, destroy escapes before seed set, clean the combine between fields.
- Genetic - select a herbicide-tolerant trait package, but rotate the trait across seasons.
- Chemical - an overlapping residual program with multiple effective modes of action, applied on small weeds.
- Mechanical - hand-rogue survivors; a single female produces hundreds of thousands of seeds, so escapes are next year's problem.
- Biological - limited direct role against Palmer, but preserve it in the insect program so an insecticide-driven mite flare does not force additional passes.
- Regulatory - Arkansas class rules constrain which auxin chemistry is available and when.
No single leg carries the program. That is the point of integration.
A cotton grower applies a broad-spectrum insecticide for a light plant bug infestation below the economic threshold. Three weeks later spider mites explode across the field. Which control method was undermined, and what is the phenomenon called?
Which of the following is an example of cultural control rather than mechanical or genetic control?
Why is regulatory pest control treated as a distinct method, and how does Arkansas reflect it in licensing?