5.3 IPM Steps and Pesticide Resistance

Why spraying first is the exam trap

A Gwinnett lawn looks off-color. A Tift County cotton consultant sees stippled leaves. A Chatham County truck gets a call that "the mosquitoes are terrible." The wrong General Standards answer in every one of those stories is the same: mix a broad-spectrum product immediately. That answer skips Rule 40-21-3's pests domain (you never recognized the organism or its biology), skips most of Chapter 1's applied methods, and skips integrated pest management (IPM).

Chapter 1 defines IPM as a strategy that uses a wide range of tactics and reduces reliance on pesticides as the only method. The goal is to prevent pests from reaching economically or aesthetically damaging levels with the least risk to the environment. Economic damage is yield, grade, or quality in cotton, peanuts, pecans, and peaches. Aesthetic damage is how a turf stand, ornamental bed, or right-of-way looks to the people who pay for it. Public-health mosquito work adds disease risk that is not a crop yield and not a golf-green color.

Spraying first fails that definition for concrete reasons you should be able to recite:

• You may treat the wrong organism (fungicide on TSWV; insecticide on dollar spot; adult fog on a larval bucket).
• You may treat the wrong stage (foliar spray for white grubs; a contact herbicide on johnsongrass rhizomes).
• You may kill natural enemies and create a secondary pest (cotton mites after a pyrethroid).
• You apply selection pressure that breeds resistance (Palmer amaranth and the "just use more" reflex).
• You may violate the label if the site or pest is not listed — the label chapter comes next; IPM does not waive it.

IPM is not a promise that you will never use a pesticide. It is a promise that chemical control, when used, sits after identification, monitoring, and a management goal, and beside biological, mechanical, cultural, physical, genetic, and regulatory tools.

The five IPM components (Core Manual Chapter 1)

Memorize the five components in order. Older short lists that collapse IPM into "scout, spray, write it down" are not the 2nd-edition Chapter 1 sequence Georgia manuals follow.

1. Identify the pest and understand its biology. Section 5.1. Key pests, occasional pests, and secondary pests live here. If you cannot name the organism, you do not have an IPM program; you have a guess.
2. Monitor the pest to be managed. Scouting, traps, mosquito landing counts or larval dips, weed mapping, disease weather watchers, degree-days where your category uses them. Monitoring is repeated. One windshield tour of a pecan orchard is not a monitoring program. Rule 40-21-5 application records ask for target pest — you cannot honestly fill that field if you never monitored.
3. Develop the pest management goal. This is where thresholds live. The goal may be suppress, prevent, or, in regulatory programs, eradicate. It is not "zero insects on every cotton leaf" and not "brown turf is always a pesticide emergency."
4. Implement the integrated pest management program. Combine compatible methods from Section 5.2. Hit the susceptible stage. Use pesticides when the goal and the label say they are needed, not because the tank is already filled from the last job.
5. Record and evaluate results. Did the tactic work? Did mites flare? Did the right-of-way rhizomes return? Evaluation feeds next week's decision. Georgia contractors record all applications; commercial applicators not on a contractor record RUP and state-restricted uses. The pests domain still cares that evaluation exists even when a particular job used only cultural sanitation.

Action thresholds versus aesthetic thresholds

Chapter 1's management-goal step is where turf companies and cotton consultants part ways, and the exam will make you say so out loud.

An economic injury level is the pest density at which damage equals the cost of control. An economic threshold or action threshold is a lower density at which you act so you never reach that injury level. In agronomic cotton and peanuts, that math is why you scout plant bugs, worms, weeds, and leaf spot instead of treating because a neighbor sprayed. Pecans and peaches use the same idea with orchard-specific counts, trap captures, and disease models: you are protecting nuts and fruit as commodities, not keeping a lawn camera-ready.

An aesthetic threshold is based on appearance, not bushels. A putting green, a Gwinnett HOA lawn, and a campus ornamental bed will trigger treatment at pest levels that would be ignored in a peanut field. That is not sloppy agronomy. It is a different management goal. It is also why Category 24 work can be pesticide-heavy if the contract defines "damage" as any blemish — IPM still requires identification and monitoring; it does not require you to pretend a lawn is a cotton crop. Conversely, a hay field or a low-visibility right-of-way interior may tolerate weed or insect levels a golf green cannot. Rights-of-way add safety and line-of-sight goals that are neither yield nor curb appeal: brush on a curve is a different threshold than a few winter annuals behind a fence.

Mosquito programs (Category 41, and government 31) use public-health and nuisance triggers: species, stage, landing rates, larval presence, and disease surveillance. Those are not peanut action thresholds and not HOA aesthetic thresholds. Source reduction and larval control still sit earlier in IPM than a default adulticide.

Write this contrast in one line: cotton and peanuts act on scouting economics; turf often acts on appearance; neither goal authorizes spraying before identification.

Pesticide resistance: rotate mode of action, do not pour more

Rule 40-21-3 General Standard 5. Pesticides includes "factors which influence effectiveness or lead to such problems as resistance to pesticides." Chapter 1's effectiveness section is where Core Manual students meet the definition.

Resistance is a heritable change in a pest population: individuals that survive a pesticide pass that ability on. It is not a clogged nozzle, not a rain-fastness miss, and not "the product got weak in the jug." Repeated use of the same mode of action selects those survivors. Georgia's loudest field example is herbicide-resistant Palmer amaranth in cotton and peanuts. Insect and mite resistance, fungicide resistance in pecan scab or peanut leaf spot, and mosquito adulticide resistance are the same evolutionary story in other categories.

What the exam will not accept as a resistance plan:

• Use more product or a higher-than-label rate
• Spray more often with the same chemistry
• Switch to a "hotter" product that has the same mode of action
• Abandon scouting because "nothing works unless we drench it"

What Chapter 1 and resistance-management programs do accept:

• Rotate modes of action (insecticide, herbicide, and fungicide grouping systems exist so you rotate sites of action, not brand names or signal words)
• Use labeled rates — rates that are too low can select resistance; rates above the label are illegal and not a resistance cure
• Use tank mixes of different modes of action only when the labels allow the mix
• Keep non-chemical tactics in the program so every generation is not screened with the same chemistry (cultivation, sanitation, thresholds, biological conservation)
• For Bt crops, follow refuge and trait-stewardship rules so susceptible insects are not eliminated from the landscape; keep scouting for pests the trait does not cover

Host resistance can itself be overcome if you treat the trait as a permanent chemical. That is why Section 5.2's Bt cotton example returns here: genetic control is an IPM tactic that still needs resistance management.

Close the chapter the way the sitting will close a pests item: identify, monitor, set the correct kind of threshold, combine methods, record what happened, and when you do use a pesticide, change the mode of action — do not turn up the volume.