9.2 IPM Principles and Tactics

Integrated pest management (IPM) is the Core answer to “when do I spray?” 40 CFR 171.103(c) requires commercial applicators to demonstrate practical knowledge of the principles and practices of pest control, not merely how to empty a tank. National Core and the U.S. Environmental Protection Agency describe IPM as a decision process that combines biological, cultural, physical/mechanical, and chemical tools to keep pests below damaging levels while reducing unnecessary risk to people, nontarget organisms, and the environment. IPM is not an organic-only certification and it is not a ban on pesticides. Labeled chemicals remain legal and often necessary in Oklahoma wheat, cotton, pasture, turf, structural Category 7A, stored-product, and public-health work. The exam failure is spray first, identify later.

Chemical control is still IPM when you use it after identification and a threshold, at a labeled site and pest, often together with non-chemical tactics, and not as the only mortality source year after year. Public-health mosquitoes and a German cockroach in a food-handling account can justify fast chemical suppression. They still do not justify skipping sanitation, habitat reduction, or a label check.

The decision order

Use this order on Core scenarios:

1. Prevention — stop the pest from arriving, reproducing, or finding food, water, and shelter.
2. Monitoring — scout and identify using Section 9.1 methods.
3. Thresholds — compare counts to an economic, aesthetic, or public-health action level.
4. Tactics — choose cultural, mechanical/physical, biological, and, when justified, chemical tools, often in combination.

Chemical tools sit in the program. Training language that says “last among equally effective options” means: do not burn a chemistry, a beneficial complex, and a neighbor’s drift complaint if mowing, exclusion, or a variety change would have held the pest below threshold. It does not mean you must watch a pecan crop infested after circle traps have already triggered, or watch Palmer amaranth go to seed, while you wait for a romantic non-chemical miracle.

Cultural tactics

Cultural practices make the crop or site a worse place for the pest to live.

Host-plant resistance is a plant-breeding or variety trait: wheat less prone to a disease, cotton that reduces feeding by certain insects, turf species that tolerate insect feeding better. It is biology you use so you spray less often. It is not a claim that a study guide, a brand, or a training course is an official replica of an exam blueprint. Scouting does not stop because a variety has an insect trait; Oklahoma cotton work still checks squares and bolls.

Crop rotation breaks weed, insect, and disease cycles. Palmer amaranth in continuous cotton or soybean sees the same canopy and the same herbicide habits. A rotation that changes planting date, residual herbicide options, and crop competition is a cultural tactic with a resistance benefit (Section 9.3). Oklahoma’s wheat–cotton–pasture mix is a real IPM landscape. A custom applicator may treat true armyworm in wheat in spring, stink bugs or bollworm in cotton in summer, and pasture broadleaves on the same farm’s upland. Rotation only works if the next crop is in the plan, including pasture-herbicide persistence that can injure a later broadleaf (Chapter 5). Cotton planted into wheat residue, which OSU has studied for Palmer management, is cultural plus chemical: residue and a preemergence herbicide are not “organic theater”; they are how you stop living on postemergence glyphosate.

Planting date, row spacing, fertility, and irrigation change canopy and pest timing. Over-fertilized, wet turf holds foliar disease. Lodged wheat holds armyworms. Mowing height on Oklahoma bermudagrass, zoysiagrass, and athletic turf is a cultural lever. Scalping stresses grass, opens the stand to weeds, and can worsen some insect and disease problems. Raising height within the species’ range thickens turf so crabgrass invasion and armyworm feeding are easier to tolerate. Mowing does not replace a labeled insecticide when soap-flush counts blow a threshold, but treating armyworms on a scalped, starved stand without fixing height is treating a symptom you keep recreating.

Sanitation in Category 7A is the difference between a gel-bait program that works and a weekly fog that does not. German cockroaches need crumbs, grease, and water. A restaurant that leaves standing water in a dish pit, cardboard under a prep table, and a leaking soda machine will refill from the same harborage after a pyrethroid space spray. Sanitation versus spray is a Core contrast: clean and dry first, then bait or crack-and-crevice where insects still live. The same idea is grain sanitation and exclusion at elevators before a rodenticide; destroying mosquito larval habitat (containers, ruts, clogged ditches) in Category 8 before fogging a neighborhood; and removing johnsongrass seed heads and Palmer escapes before they replenish the seed bank.

Mechanical and physical tactics

Mechanical/physical tools kill or exclude without a pesticidal active ingredient:

• Cultivation, hoeing, and hand-roguing Palmer amaranth escapes before female plants seed.
• Mowing johnsongrass before viable seed, knowing rhizomes remain.
• Traps: pecan weevil circle traps for timing, armyworm pheromone or sweep counts, cockroach sticky traps as monitors (they are not always stand-alone control), rodent snap traps placed and checked so nontargets are not an afterthought.
• Exclusion: door sweeps, screens, sealing utility penetrations for 7A insects and rodents; mosquito screens; keeping dumpsters away from kitchen doors.
• Mulch, landscape fabric, and physical barriers in ornamental beds.
• Vacuum, heat, or cold in some structural accounts—only where they actually fit the pest and the site.

These tactics still require identification. Cultivating a perennial johnsongrass patch can spread rhizomes. Vacuuming German cockroaches without fixing grease lines is a photo-op. A circle trap that is never checked is not monitoring.

Biological tactics

Biological control uses living antagonists: predators, parasitoids, pathogens, or grazing animals in some vegetation systems.

Cotton and pecan spider mite management often depends on predatory mites and insects. A broad-spectrum pyrethroid that hammers a bollworm flight but erases predators is a chemical tactic with a biological cost you will pay in miticide later. Conserving beneficials—choosing more selective products when they still meet the threshold, avoiding extra tank-mix partners, leaving unsprayed borders where the label and the crop allow—is IPM.

Bt (Bacillus thuringiensis) foliar products and some cotton insect traits are biological or host-plant tools that still carry IRAC groups and resistance rules. If the product is registered as a pesticide, it is a pesticide. Do not call a jug “biological” because the marketing sounds green. Read the label.

Pasture grazing and competitive forage stands are biological-plus-cultural tools against some weeds; they do not make an unlabeled pasture herbicide legal on cotton.

Chemical tactics inside IPM

When you do use a pesticide:

• The pest and site must be labeled (Section 9.1; Chapter 4).
• The type of pesticide must match the organism (Chapter 5).
• Time the application to the vulnerable stage (small Palmer, pecan weevil adults before eggs are in the nut, armyworm larvae still in the canopy, cockroach baits where nymphs feed).
• Use the labeled rate. Cutting rates is not IPM and is a resistance problem in Section 9.3.
• Combine with cultural and mechanical tools so chemistry is not the only mortality.

Oklahoma pasture herbicide, cotton insecticide, turf caterpillar product, 7A gel bait, rodent bait in a tamper-resistant station, and Category 8 larvicide are all chemical IPM tools when they follow that order. IPM does not mean the organic aisle. It means you can explain why this product, this day, this rate, after prevention and scouting.

Recordkeeping of scouting

IPM collapses without notes. Oklahoma commercial and noncommercial applicators already keep pesticide activity records for at least two years at the principal business location (2 O.S. § 3-83; contents in OAC 35:30-17-21). Scouting records are not a substitute for those legal application records. They are how you justify why an application happened: pest name, density, threshold used, life stage, and which non-chemical steps you already took. A 7A route sheet that only says “sprayed” cannot support a bait rotation or a health-department complaint. A cotton consultant’s square-inspection notes are how you avoid treating below threshold when beneficials are already crashing worms. Circle-trap counts in a pecan grove are how you avoid a calendar spray in a drought year when adults have not emerged.

Write the field or account, date, method, count, stage, and decision (treat, wait, sanitation only). That notebook is also how Section 9.3 resistance rotation stays honest: you cannot “rotate modes” if nobody recorded which IRAC, HRAC, or FRAC group went out last time.

Wheat–cotton–pasture, urban 7A sanitation versus fog, and turf mowing height are three Oklahoma pictures of one rule: prevent and monitor first; use chemistry as a programmed tactic, not as a reflex.