Mode-of-Action Explorer
Find a chemistry by target site. The organising question is the IRAC mode-of-action group: products in the same group are, for resistance purposes, the same tool.
19 rows listed — showing all.
| IRAC group | Class | Target site | Example active ingredients | Typical uses | Resistance notes |
|---|---|---|---|---|---|
| 1A | Acetylcholinesterase inhibitors — carbamates | Acetylcholinesterase (AChE) | Carbaryl, propoxur | Crack-and-crevice and perimeter uses (varies by label) | Target-site AChE insensitivity and metabolic resistance documented in several pests. |
| 1B | Acetylcholinesterase inhibitors — organophosphates | Acetylcholinesterase (AChE) | Chlorpyrifos (restricted uses), malathion | Agricultural and public-health uses; many former indoor uses withdrawn | Long resistance history; regulatory restrictions have reduced urban use. |
| 2B | GABA-gated chloride channel blockers — phenylpyrazoles (fiproles) | GABA-gated chloride channel; also glutamate-gated chloride channels (GluCl) | Fipronil | Ant and cockroach baits; non-repellent liquid termite soil treatment; social transfer | Resistance reported but less widespread than pyrethroids; stewardship by placement. |
| 3A | Sodium channel modulators — pyrethroids | Voltage-gated sodium channel (held open) | Permethrin, cyfluthrin, deltamethrin, lambda-cyhalothrin | Broad structural, perimeter and fabric uses | Widespread kdr + metabolic resistance, esp. bed bugs, German cockroaches, flies. |
| 4A | Nicotinic acetylcholine receptor competitive modulators — neonicotinoids | Nicotinic acetylcholine receptor (nAChR) | Imidacloprid, dinotefuran, thiamethoxam | Baits (ant/cockroach/fly), systemic agricultural uses | Resistance documented in several agricultural pests; pollinator profile drives regulation. |
| 5 | Nicotinic acetylcholine receptor allosteric modulators, Site I — spinosyns | nAChR (allosteric, Site I — a different site from Group 4A) | Spinosad, spinetoram | Ant and fly baits; stored-product and agricultural uses per label | A distinct target site from the neonicotinoids, so a genuine rotation partner — not the same tool as Group 4A. |
| 6 | Glutamate-gated chloride channel (GluCl) allosteric modulators — avermectins | Glutamate-gated chloride channels | Abamectin | Ant and cockroach baits; agricultural uses per label | Slow action permits social transfer in baiting; resistance documented in some agricultural pests. |
| 7A | Juvenile hormone analogues (IGRs) — subgroup 7A | Juvenile hormone receptor pathway | Methoprene, hydroprene | Flea, cockroach, stored-product and mosquito-larva control | Slow action; resistance uncommon but stage-specific — adults unaffected directly. |
| 7B | Juvenile hormone analogue (IGR) — subgroup 7B | Juvenile hormone receptor pathway | Fenoxycarb | Flea and stored-product uses per label | Stage-specific like the other juvenile-hormone analogues; combined with sanitation and adulticides. |
| 7C | Juvenile hormone analogue (IGR) — subgroup 7C | Juvenile hormone receptor pathway | Pyriproxyfen | Cockroach, flea and mosquito-larva control per label | Potent at very low rates; also sterilises exposed adult females of some species. |
| 8C | Miscellaneous non-specific (multi-site) inhibitors — fluorides | Multi-site, respiratory/metabolic (gas) | Sulfuryl fluoride | Whole-structure fumigation by licensed specialists only | No residual; last-resort use; dosage and exposure per label tables. See Chemistry for the safety apparatus. |
| 8D | Miscellaneous non-specific (multi-site) inhibitors — borates | Multi-site; ingested borate disrupts gut and metabolic function | Boric acid, borax, disodium octaborate | Baits, dusts in wall voids, and wood treatments per label | A stomach poison, not a desiccant: slow, no knockdown, and persistent while dry. Biochemical resistance is uncommon. |
| 11A | Microbial disruptors of insect gut membranes — Bacillus thuringiensis | Gut cell membranes (crystal toxins activated in the alkaline gut) | Bt israelensis (mosquito and black-fly larvae), Bt kurstaki (caterpillars, agricultural) | Larviciding of standing water; agricultural caterpillar control per label | Strain-specific: the strain on the label decides the target. Resistance documented in a few agricultural pests. |
| 13 | Uncouplers of oxidative phosphorylation via disruption of the proton gradient — pyrroles | Mitochondrial proton gradient (uncoupler, via an active metabolite) | Chlorfenapyr | Cockroach, termite and bed bug uses per label | Pro-insecticide: the insect's own enzymes convert it to the uncoupling metabolite. Valued as a non-pyrethroid rotation option. |
| 15 | Inhibitors of chitin biosynthesis (affecting CHS1) — benzoylureas | Chitin synthase 1; the new cuticle fails at moulting | Hexaflumuron, noviflumuron, diflubenzuron | Termite baiting systems; stored-product and agricultural uses per label | Slow and moult-linked — exactly why these are the chemistry of termite baits: foragers share bait before it kills. |
| 22A | Voltage-dependent sodium channel blockers — oxadiazines | Voltage-gated sodium channel (blocked, not held open) | Indoxacarb | Cockroach and ant baits | Pro-insecticide activated by insect enzymes; a blocker, mechanistically opposite to the Group 3A modulators and a useful rotation partner. |
| 24A | Mitochondrial complex IV electron-transport inhibitors — phosphides | Cytochrome c oxidase (complex IV), via phosphine gas | Phosphine (generated from aluminium or magnesium phosphide) | Fumigation of stored commodities and structures by licensed specialists only | Phosphine resistance is documented in stored-product beetles and moths — one reason commodity fumigation is monitored, not assumed. |
| 28 | Ryanodine receptor modulators — diamides | Ryanodine receptor; uncontrolled calcium release paralyses muscle | Chlorantraniliprole | Termite, ant and agricultural uses per label | A muscle target, not a nerve-channel target; resistance management still applies — rotate groups. |
| — (physical) | Desiccant dusts (physical mode — outside the numbered IRAC scheme) | Cuticle waterproofing destroyed → water loss. Silica gel acts by sorption of cuticle lipids; diatomaceous earth by abrasion plus sorption | Silica gel (amorphous silica), diatomaceous earth (label grades only) | Wall voids, harbourage, bed bug programmes | Physical mode: biochemical resistance unlikely; must stay dry. The two dusts are not interchangeable — their mechanisms differ. |
Notes: group numbers and subgroup letters follow the IRAC Mode of Action Classification. Group 7 splits into 7A (methoprene, hydroprene), 7B (fenoxycarb) and 7C (pyriproxyfen); Group 8 holds the multi-site inhibitors, including fumigant fluorides (8C) and borates (8D). Only the desiccant dusts sit outside the numbered scheme, because their mode is physical. Example ingredients illustrate the class and are not recommendations. Fumigant and restricted-use products are for licensed professionals only.