Eight Years of Pest Control Chemistry: Organophosphates Nearly Gone
Key result: Between 2016 and 2023, California structural pest control applications grew 33 percent. Insect growth regulator applications grew 268 percent and neonicotinoids 168 percent. Pyrethroids grew more slowly than the market, fipronil fell 13 percent, and organophosphates other than acephate fell 96 percent, nearly to zero.
Reading the industry’s chemistry by what it does, not what it weighs
Our analysis of what structural pest control applies tracked chemistry in pounds, and found every category volatile with no clean trend. Pounds are dominated by fumigation and by a few heavy compounds. Counting applications instead, the number of times each active ingredient was used, shows how the day-to-day work has changed.
We read every California Pesticide Use Report archive from 2016 to 2023, eight complete years, and summed the reported application counts for every active ingredient used in structural pest control. Over the period, total structural applications rose from 14,172,516 to 18,815,415, so a class has to grow faster than 33 percent to gain share.
The winners and the losers
| Class | Applications, 2016 | Applications, 2023 | Change |
|---|---|---|---|
| Insect growth regulators | 367,835 | 1,353,277 | +268% |
| Neonicotinoids | 1,034,040 | 2,774,121 | +168% |
| Rodenticides | 1,689,613 | 3,042,550 | +80% |
| All structural applications | 14,172,516 | 18,815,415 | +33% |
| Pyrethroids | 8,197,083 | 10,477,743 | +28% |
| Fipronil | 1,110,616 | 963,104 | −13% |
| Organophosphates and carbamates | 102,659 | 88,370 | −14% |
| Botanical pyrethrins | 559,211 | 279,458 | −50% |
Source: California Department of Pesticide Regulation, Pesticide Use Reports 2016 to 2023, site code 10, application counts by active ingredient summed by class. A product with two active ingredients counts once in each ingredient’s class. Class membership is listed in the methods. Author calculation.
What it means. Three classes gained share: insect growth regulators, neonicotinoids and rodenticides. Pyrethroids, still the bulk of the work, grew a little slower than the market, falling from 57.8 to 55.7 pyrethroid ingredient-applications per 100 structural applications. Fipronil’s share fell from 7.8 percent of applications to 5.1 percent.
What limits it. Classes are defined by active ingredient, and some products combine classes. The counts are applications as businesses report them on monthly summaries.
Growth regulators and neonicotinoids
| Active ingredient | Class | 2016 | 2020 | 2022 | 2023 |
|---|---|---|---|---|---|
| Pyriproxyfen | Growth regulator | 164,638 | 313,411 | 508,661 | 999,259 |
| Novaluron | Growth regulator | 8,381 | 73,999 | 153,135 | 167,972 |
| Dinotefuran | Neonicotinoid | 247,350 | 740,975 | 1,257,372 | 1,371,182 |
| Clothianidin | Neonicotinoid | 9,261 | 31,021 | 43,837 | 423,184 |
| Thiamethoxam | Neonicotinoid | 98,566 | 196,183 | 316,841 | 313,035 |
| Imidacloprid | Neonicotinoid | 621,077 | 726,139 | 672,336 | 635,893 |
Source: as above.
What it means. The neonicotinoid growth is not imidacloprid, which was flat across the eight years. It is dinotefuran, up 5.5 times, and in 2023 clothianidin. Pyriproxyfen roughly doubled in 2023 alone. Much of that one-year jump traces to a single product: Vendetta Nitro, a cockroach gel bait combining clothianidin and pyriproxyfen, went from 19,452 applications in 2022 to 390,499 in 2023, as our product ranking shows. Clothianidin’s rise that year was 379,347 applications.
What limits it. One product can move a class in a single year, so the 2023 figures for clothianidin and pyriproxyfen should not be read as a durable trend on their own. Dinotefuran’s rise is spread across eight years and many reports.
Inside the pyrethroids: a quiet replacement
| Pyrethroid | 2016 | 2023 | Change |
|---|---|---|---|
| Lambda-cyhalothrin | 650,217 | 1,702,976 | +162% |
| Alpha-cypermethrin | 0 | 541,951 | new from 2021 |
| Prallethrin | 160,597 | 459,489 | +186% |
| Bifenthrin | 2,793,632 | 3,521,513 | +26% |
| Deltamethrin | 1,387,368 | 1,851,078 | +33% |
| Permethrin | 813,708 | 506,470 | −38% |
| Beta-cyfluthrin | 740,171 | 559,016 | −24% |
| Cyfluthrin | 872,330 | 252,184 | −71% |
| Gamma-cyhalothrin | 108,026 | 25,890 | −76% |
Source: as above.
What it means. The pyrethroid total grew modestly, but its membership turned over. Cyfluthrin lost 71 percent of its applications and permethrin 38 percent, while lambda-cyhalothrin more than doubled and alpha-cypermethrin went from no recorded use to more than half a million applications within three years of first appearing.
What limits it. We do not know why products were switched; price, label changes, resistance management and distributor relationships are all possible, and the reports record none of them.
The organophosphate exit
| Active ingredient | 2016 | 2019 | 2023 |
|---|---|---|---|
| Propoxur (carbamate) | 16,525 | 4,079 | 314 |
| Malathion | 4,254 | 974 | 0 |
| Chlorpyrifos | 3,816 | 5,143 | 36 |
| All organophosphates and carbamates except acephate | 25,679 | 11,276 | 1,132 |
| Acephate | 76,980 | 125,540 | 87,238 |
Source: as above.
What it means. Outside acephate, the older organophosphate and carbamate insecticides have all but left California structural pest control, down 96 percent in eight years to 1,132 applications. Acephate is the exception and held steady. Botanical pyrethrins also halved over the period.
What limits it. These were already small. Their disappearance changes little in the total but marks the end of a chemistry era in this market.
Something new: a fungus
Beauveria bassiana strain GHA, a fungus that infects insects and is registered as a biological pesticide, did not appear in structural use at all from 2016 to 2018. It was recorded in 4,802 applications in 2019 and 109,386 in 2023. It remains under 1 percent of structural applications.
Checks on the trends
1. Complete eight-year series
Result. All eight archives from 2016 to 2023 were read in full, 58 county files each. Including 2017 and 2019 fills the gaps in our earlier six-year series.
2. Endpoints against the path
Method. Checked whether each headline change is a steady trend or an artifact of the two end years.
Result. Neonicotinoids and insect growth regulators rose in most years; botanical pyrethrins and cyfluthrin fell in every year. Clothianidin’s and pyriproxyfen’s 2023 jumps are single-year steps driven by one product and are reported as such. Acetamiprid spiked to 223,967 applications in 2020 and fell back, which is why it is not described as a trend.
3. Rodenticides
Result. The rodenticide rise is explained in our report on California’s rodenticide ban: second-generation anticoagulants fell 85 percent in 2021 and were replaced, not removed.
Related research: registrant shares, 2016 to 2023.
Download the data
The tables in this report are published as CSV files under a Creative Commons Attribution 4.0 licence. You may republish, remix and build on them, including commercially, with attribution to The Pest Control Brief and a link to this page.
- Applications by chemical class with 2016 index, 2016 to 2023 (CSV, 56 rows)
- Applications, pounds and reports for 73 active ingredients, 2016 to 2023 (CSV, 584 rows)
How to cite this report
The Pest Control Brief, “Eight Years of Pest Control Chemistry: Neonicotinoids and Growth Regulators Up, Organophosphates Nearly Gone”, 2 October 2026. https://thepestcontrolbrief.com/pest-control-chemistry-trends/
References
- California Department of Pesticide Regulation. Pesticide Use Report annual archives, 2016 to 2023. files.cdpr.ca.gov/pub/outgoing/pur_archives/. Accessed 2 October 2026.
- California Department of Pesticide Regulation. PUR field definitions, readme_excel.xlsx, supplied inside the 2023 archive. Defines the application count for non-agricultural monthly summary reports.
- The Pest Control Brief. The 15 products behind half of California’s pest control. thepestcontrolbrief.com/most-used-pest-control-products. Source of the Vendetta Nitro figures.
How the classes were built
Scope. Every Pesticide Use Report record with site code 10, Structural Pest Control, 2016 to 2023.
Unit. The application count field, summed by active ingredient, then by class.
Classes. Pyrethroids: bifenthrin, deltamethrin, lambda- and gamma-cyhalothrin, alpha-, zeta- and cypermethrin, permethrin, cyfluthrin and beta-cyfluthrin, esfenvalerate, fenvalerate, prallethrin, phenothrin, tetramethrin, etofenprox, imiprothrin, cyphenothrin, allethrins, tau-fluvalinate, fenpropathrin, transfluthrin, metofluthrin and resmethrin, where present. Neonicotinoids: imidacloprid, dinotefuran, thiamethoxam, clothianidin, acetamiprid. Insect growth regulators: pyriproxyfen, novaluron, hydroprene, methoprene and S-methoprene, noviflumuron, hexaflumuron, diflubenzuron. Organophosphates and carbamates: acephate, chlorpyrifos, malathion, diazinon, propoxur, bendiocarb, carbaryl, trichlorfon. Rodenticides: the eleven compounds in our rodenticide report. Botanical pyrethrins kept separate from synthetic pyrethroids.
Limitations. Multi-ingredient products count once per ingredient, so class totals cannot be summed to the all-applications total. About 12 percent of licences state no application count on some reports. California only.
Last reviewed: 2 October 2026.
For trade and environmental reporters
Most quotable statistics
- Neonicotinoid applications in California structural pest control rose 168 percent from 2016 to 2023, against 33 percent for all applications.
- Insect growth regulator applications rose 268 percent, led by pyriproxyfen.
- Dinotefuran applications rose 5.5 times, from 247,350 to 1,371,182, while imidacloprid was flat.
- Older organophosphates and carbamates fell 96 percent, to 1,132 applications in 2023; acephate held steady.
- Cyfluthrin applications fell 71 percent while lambda-cyhalothrin rose 162 percent.
Caveats that travel with them
California structural pest control only. Applications, not pounds. Single products can move a class in a single year.
Press summary
The chemistry of professional pest control in California has shifted toward neonicotinoids and insect growth regulators, according to an eight-year analysis of state pesticide use reports by The Pest Control Brief. Between 2016 and 2023, structural applications grew 33 percent, but neonicotinoid applications grew 168 percent, driven by dinotefuran, and insect growth regulators 268 percent. Pyrethroids remained the majority of the work but lost a little share, with cyfluthrin and permethrin replaced by lambda-cyhalothrin and alpha-cypermethrin. Fipronil’s share fell from 7.8 to 5.1 percent of applications, and older organophosphate and carbamate insecticides fell 96 percent.
Headlines editors could use
- Pest control’s chemistry is shifting to neonicotinoids and growth regulators
- Neonicotinoid use in California pest control up 168 percent in eight years
- The organophosphate era of pest control is nearly over
- Inside the pyrethroids: the quiet product swap in pest control
Questions about the trends
Are pest control companies using more neonicotinoids?
In California structural pest control, yes. Neonicotinoid applications rose from 1,034,040 in 2016 to 2,774,121 in 2023, mainly dinotefuran and, in 2023, clothianidin.
Which pest control chemicals are growing fastest?
Insect growth regulators, up 268 percent from 2016 to 2023, and neonicotinoids, up 168 percent, against 33 percent for all applications.
Are pyrethroids declining?
No, they grew 28 percent, slightly slower than the market. Some individual pyrethroids fell sharply, including cyfluthrin and permethrin, while others rose.
Do exterminators still use organophosphates?
Very little, apart from acephate. Other organophosphates and carbamates fell from 25,679 applications in 2016 to 1,132 in 2023.
Is fipronil use falling?
Slightly. Fipronil applications fell 13 percent from 2016 to 2023, and its share of all structural applications fell from 7.8 to 5.1 percent.
What is an insect growth regulator?
An insecticide that disrupts insect development rather than killing adults directly. Pyriproxyfen and novaluron are the most used in California structural pest control.
Are biological pesticides growing?
From a small base. Beauveria bassiana, an insect-infecting fungus, went from no recorded structural use in 2016 to 109,386 applications in 2023.
Where can I get the yearly figures?
Class totals and 73 individual active ingredients, eight years each, are in the CSV files above.
