Insecticide#Organochlorine compounds

In 2016 insecticides were estimated to account for 18% of worldwide pesticide sales.{{Cite journal |last=Delso |first=N. Simon |date=2015 |title=Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites |journal=Environmental Science and Pollution Research |volume=22 |issue=1 |pages=5–34 |bibcode=2015ESPR...22....5S |doi=10.1007/s11356-014-3470-y |pmc=4284386 |pmid=25233913}} Worldwide sales of insecticides in 2018 were estimated as $ 18.4 billion, of which 25% were neonicotinoids, 17% were pyrethroids, 13% were diamides, and the rest were many other classes which sold for less than 10% each of the market.{{Cite journal |last=Sparks |first=Thomas C |date=2024 |title=Insecticide mixtures—uses, benefits and considerations |url=https://doi.org/10.1002/ps.7980 |journal=Pest Management Science |doi=10.1002/ps.7980 |pmid=38356314 |via=Wiley}}

Insecticides are most usefully categorised according to their modes of action. The insecticide resistance action committee (IRAC) lists 30 modes of action plus unknowns. There can be several chemical classes of insecticide with the same mode or action. IRAC lists 56 chemical classes plus unknowns.

The mode of action describes how the insecticide kills or inactivates a pest.

{{main|pesticide#Development of new pesticides}}Insecticides with systemic activity against sucking pests, which are safe to pollinators, are sought after,{{Cite journal |last=Sparks |first=Thomas |date=August 2022 |title=Innovation in insecticide discovery: Approaches to the discovery of new classes of insecticides |journal=Pest Management Science |volume=78 |issue=8 |pages=3226–3247 |doi=10.1002/ps.6942 |pmid=35452182 |s2cid=248322585}}{{Cite journal |last=Sparks |first=Thomas |date=May 2023 |title=Insecticide discovery–"Chance favors the prepared mind" |journal=Pesticide Biochemistry and Physiology |volume=192 |pages=105412 |doi=10.1016/j.pestbp.2023.105412 |pmid=37105622 |bibcode=2023PBioP.19205412S |s2cid=257790593}}{{Cite journal |last=Umetsu |first=Noriharu |date=May 2020 |title=Development of novel pesticides in the 21st century |journal=Journal of Pesticide Science |volume=45 |issue=2 |pages=54–74 |doi=10.1584/jpestics.D20-201 |pmc=7581488 |pmid=33132734}} particularly in view of the partial bans on neonicotinoids. Revised 2023 guidance by registration authorities describes the bee testing that is required for new insecticides to be approved for commercial use.{{Cite web |date=11 May 2023 |title=Bees and pesticides: updated guidance for assessing risks |url=https://www.efsa.europa.eu/en/news/bees-and-pesticides-updated-guidance-assessing-risks |access-date=26 Nov 2023 |website=European Food Safety Authority}}{{Cite journal |last=Adriaanse |first=Pauline |date=11 May 2023 |title=Revised guidance on the risk assessment of plant protection products on bees (Apis mellifera, Bombus spp. and solitary bees) |journal=EFSA Journal |volume=21 |issue=5 |pages=7989 |doi=10.2903/j.efsa.2023.7989 |pmc=10173852 |pmid=37179655}}{{Cite web |date=28 June 2023 |title=How We Assess Risks to Pollinators |url=https://www.epa.gov/pollinator-protection/how-we-assess-risks-pollinators |website=United States Environmental Protection Agency}}{{Cite web |title=Managing Pesticide Risk to Insect Pollinators; Laws, Policies and Guidance |url=https://www.oecd.org/chemicalsafety/risk-mitigation-pollinators/laws-policies-guidance.htm |access-date=28 Nov 2023 |website=Organisation for Economic Cooperation and Development}}

Insecticides may be systemic or non-systemic (contact insecticides).{{cite journal |last1=Zhang |first1=Y |last2=Lorsbach |first2=BA |last3=Castetter |first3=S |last4=Lambert |first4=WT |last5=Kister |first5=J |last6=Wang |first6=N |date=2018 |title=Physicochemical property guidelines for modern agrochemicals |journal=Pest Management Science |volume=74 |issue=9 |page=1979-1991 |doi=10.1002/ps.5037 |pmid=29667318 |s2cid=4937939}}{{cite journal |last1=Hofstetter |first1=S |date=2018 |title=How To Design for a Tailored Subcellular Distribution of Systemic Agrochemicals in Plant Tissues |url=https://backend.orbit.dtu.dk/ws/files/167227061/Rev_Hofstetter_et_al_intracellular_localization_of_agrochemicals.pdf |journal=J. Agric. Food Chem. |volume=66 |issue=33 |pages=8687–8697 |doi=10.1021/acs.jafc.8b02221 |pmid=30024749 |bibcode=2018JAFC...66.8687H |s2cid=261974999}} Systemic insecticides penetrate into the plant and move (translocate) inside the plant. Translocation may be upward in the xylem, or downward in the phloem or both. Systemicity is a prerequisite for the pesticide to be used as a seed-treatment. Contact insecticides (non-systemic insecticides) remain on the leaf surface and act through direct contact with the insect.

Insects feed from various compartments in the plant. Most of the major pests are either chewing insects or sucking insects.{{Cite web |last=Cloyd |first=Raymond A. |date=10 May 2022 |title=Insect and Mite Pests Feeding Behaviors and Plant Damage |url=https://gpnmag.com/article/dr-bugs-insect-and-mite-pests-feeding-behaviors-and-plant-damage |access-date=3 November 2024 |website=Greenhouse Product News}} Chewing insects, such as caterpillars, eat whole pieces of leaf. Sucking insects use feeding tubes to feed from phloem (e.g. aphids, leafhoppers, scales and whiteflies), or to suck cell contents (e.g. thrips and mites). An insecticide is more effective if it is in the compartment the insect feeds from. The physicochemical properties of the insecticide determine how it is distributed throughout the plant.

The best known organochloride, DDT, was created by Swiss scientist Paul Müller. For this discovery, he was awarded the 1948 Nobel Prize for Physiology or Medicine.{{cite web |editor=Karl Grandin | title=Paul Müller Biography | url=http://nobelprize.org/nobel_prizes/medicine/laureates/1948/muller-bio.html | work=Les Prix Nobel | publisher=The Nobel Foundation | year=1948 | access-date=2008-07-24}} DDT was introduced in 1944. It functions by opening sodium channels in the insect's nerve cells.{{Cite journal |author=Vijverberg |title=Similar mode of action of pyrethroids and DDT on sodium channel gating in myelinated nerves |journal=Nature |volume=295 |issue=5850 |pages=601–603 |year=1982 |display-authors=1 |bibcode=1982Natur.295..601V |last2=Van Den Bercken |first2=Joep |doi=10.1038/295601a0|pmid=6276777 |s2cid=4259608 }} The contemporaneous rise of the chemical industry facilitated large-scale production of chlorinated hydrocarbons including various cyclodiene and hexachlorocyclohexane compounds. Although commonly used in the past, many older chemicals have been removed from the market due to their health and environmental effects (e.g. DDT, chlordane, and toxaphene).{{Cite web |date=Sep 2002 |title=Public Health Statement for DDT, DDE, and DDD |url=https://www.atsdr.cdc.gov/ToxProfiles/tp35-c1-b.pdf |url-status=live |archive-url=https://web.archive.org/web/20080923121618/http://www.atsdr.cdc.gov/toxprofiles/tp35-c1-b.pdf |archive-date=2008-09-23 |access-date=Dec 9, 2018 |website=atsdr.cdc.gov |publisher=ATSDR}}{{Cite web |date=Apr 18, 2012 |title=Medical Management Guidelines (MMGs): Chlordane |url=https://www.atsdr.cdc.gov/MMG/MMG.asp?id=349&tid=62 |access-date=Dec 9, 2018 |website=atsdr.cdc.gov |publisher=ATSDR}}

Organophosphates are another large class of contact insecticides. These also target the insect's nervous system. Organophosphates interfere with the enzymes acetylcholinesterase and other cholinesterases, causing an increase in synaptic acetylcholine and overstimulation of the parasympathetic nervous system,{{cite journal |vauthors=Colović MB, Krstić DZ, Lazarević-Pašti TD, Bondžić AM, Vasić VM |date=May 2013 |title=Acetylcholinesterase inhibitors: pharmacology and toxicology |journal=Current Neuropharmacology |volume=11 |issue=3 |pages=315–35 |doi=10.2174/1570159X11311030006 |pmc=3648782 |pmid=24179466}} killing or disabling the insect. Organophosphate insecticides and chemical warfare nerve agents (such as sarin, tabun, soman, and VX) have the same mechanism of action. Organophosphates have a cumulative toxic effect to wildlife, so multiple exposures to the chemicals amplifies the toxicity. In the US, organophosphate use declined with the rise of substitutes.{{Cite journal | doi = 10.1126/science.341.6147.730 | title = Infographic: Pesticide Planet | journal = Science | volume = 341 | issue = 6147 | pages = 730–731 | year = 2013 | pmid = 23950524| bibcode = 2013Sci...341..730. }} Many of these insecticides, first developed in the mid 20th century, are very poisonous.{{Cite web |date=Aug 1996 |title=Toxicological Profile for Toxaphene |url=https://ntp.niehs.nih.gov/ntp/htdocs/chem_background/exsumpdf/toxaphene_508.pdf |access-date=Dec 9, 2018 |website=ntp.niehs.nih.gov |publisher=ATSDR |pages=5}} Many organophosphates do not persist in the environment.

Pyrethroid insecticides mimic the insecticidal activity of the natural compound pyrethrin, the biopesticide found in Pyrethrum (Now Chrysanthemum and Tanacetum) species. They have been modified to increase their stability in the environment. These compounds are nonpersistent sodium channel modulators and are less toxic than organophosphates and carbamates. Compounds in this group are often applied against household pests.{{Cite journal| last1=Class |first1=Thomas J. |last2=Kintrup |first2=J. | title=Pyrethroids as household insecticides: analysis, indoor exposure and persistence | journal=Fresenius' Journal of Analytical Chemistry |volume=340 | issue=7|pages=446–453 | year=1991 |doi=10.1007/BF00322420 |s2cid=95713100 }} Some synthetic pyrethroids are toxic to the nervous system.{{Cite book |last=Soderlund |first=David |title=Hayes' Handbook of Pesticide Toxicology |publisher=Academic Press |year=2010 |isbn=978-0-12-374367-1 |editor-last=Kreiger |editor-first=Robert |edition=3rd |pages=1665–1686 |chapter=Chapter 77 – Toxicology and Mode of Action of Pyrethroid Insecticides |oclc=918401061 |name-list-style=vanc}}

Neonicotinoids are a class of neuro-active insecticides chemically similar to nicotine.(with much lower acute mammalian toxicity and greater field persistence). These chemicals are acetylcholine receptor agonists. They are broad-spectrum systemic insecticides, with rapid action (minutes-hours). They are applied as sprays, drenches, seed and soil treatments. Treated insects exhibit leg tremors, rapid wing motion, stylet withdrawal (aphids), disoriented movement, paralysis and death.{{cite web|url=http://edis.ifas.ufl.edu/pi117|title=Pesticide Toxicity Profile: Neonicotinoid Pesticides|first=Frederick M.|last=Fishel|date=9 March 2016|access-date=11 March 2012|archive-date=28 April 2007|archive-url=https://web.archive.org/web/20070428035003/http://edis.ifas.ufl.edu/PI117|url-status=dead}}Imidacloprid, of the neonicotinoid family, is the most widely used insecticide in the world.{{cite book |last=Yamamoto |first=Izuru |title=Nicotinoid Insecticides and the Nicotinic Acetylcholine Receptor |publisher=Springer-Verlag |year=1999 |isbn=978-4-431-70213-9 |editor-last=Yamamoto |editor-first=Izuru |location=Tokyo |pages=3–27 |contribution=Nicotine to Nicotinoids: 1962 to 1997 |oclc=468555571 |editor2-last=Casida |editor2-first=John |editor2-link=John E. Casida |name-list-style=vanc}} In the late 1990s neonicotinoids came under increasing scrutiny over their environmental impact and were linked in a range of studies to adverse ecological effects, including honey-bee colony collapse disorder (CCD) and loss of birds due to a reduction in insect populations. In 2013, the European Union and a few non EU countries restricted the use of certain neonicotinoids.{{Cite journal |last=Cressey |first=D |date=2013 |title=Europe debates risk to bees |journal=Nature |volume=496 |issue=7446 |pages=408 |bibcode=2013Natur.496..408C |doi=10.1038/496408a |issn=1476-4687 |pmid=23619669 |doi-access=free}}{{Cite journal |last1=Gill |first1=RJ |last2=Ramos-Rodriguez |first2=O |last3=Raine |first3=NE |date=2012 |title=Combined pesticide exposure severely affects individual- and colony-level traits in bees |journal=Nature |volume=491 |issue=7422 |pages=105–108 |bibcode=2012Natur.491..105G |doi=10.1038/nature11585 |issn=1476-4687 |pmc=3495159 |pmid=23086150}}{{Cite journal |vauthors=Dicks L |date=2013 |title=Bees, lies and evidence-based policy |journal=Nature |volume=494 |issue=7437 |pages=283 |bibcode=2013Natur.494..283D |doi=10.1038/494283a |issn=1476-4687 |pmid=23426287 |doi-access=free}}{{Cite journal |last=Stoddart |first=C |date=2012 |title=The buzz about pesticides |journal=Nature |doi=10.1038/nature.2012.11626 |issn=1476-4687 |s2cid=208530336 |doi-access=free}}{{Cite journal |vauthors=Osborne JL |date=2012 |title=Ecology: Bumblebees and pesticides |journal=Nature |volume=491 |issue=7422 |pages=43–45 |bibcode=2012Natur.491...43O |doi=10.1038/nature11637 |issn=1476-4687 |pmid=23086148 |s2cid=532877}}{{Cite journal |last=Cressey |first=D |date=2013 |title=Reports spark row over bee-bothering insecticides |journal=Nature |doi=10.1038/nature.2013.12234 |issn=1476-4687 |s2cid=88428354}}{{Cite web |date=30 May 2013 |title=Bees & Pesticides: Commission goes ahead with plan to better protect bees |url=http://ec.europa.eu/food/animal/liveanimals/bees/neonicotinoids_en.htm |archive-url=https://web.archive.org/web/20130621042322/http://ec.europa.eu/food/animal/liveanimals/bees/neonicotinoids_en.htm |archive-date=21 June 2013}}{{Cite web|url=http://www.columbiatribune.com/news/2012/feb/19/insecticides-taking-toll-on-honeybees/|archiveurl=https://web.archive.org/web/20120318005423/http://www.columbiatribune.com/news/2012/feb/19/insecticides-taking-toll-on-honeybees/|url-status=dead|title=Insecticides taking toll on honeybees|archivedate=March 18, 2012}} and its potential to increase the susceptibility of rice to planthopper attacks.{{cite journal |url=http://scienceindex.com/stories/2068471/Possible_connection_between_imidaclopridinduced_changes_in_rice_gene_transcription_profiles_and_susceptibility_to_the_brown_plant_hopperNilaparvatalugensStl_Hemiptera_Delphacidae.html |last1=Yao |first1=Cheng |first2=Zhao-Peng |last2=Shi |first3=Li-Ben |last3=Jiang |first4=Lin-Quan |last4=Ge |first5=Jin-Cai |last5=Wu |first6=Gary C. |last6=Jahn |title=Possible connection between imidacloprid-induced changes in rice gene transcription profiles and susceptibility to the brown plant hopper Nilaparvata lugens Stål (Hemiptera: Delphacidae) |journal=Pesticide Biochemistry and Physiology |volume=102 |issue=3 |pages=213–219 |date=20 January 2012 |issn=0048-3575 |doi=10.1016/j.pestbp.2012.01.003 |pmid=22544984 |pmc=3334832 |bibcode=2012PBioP.102..213C |url-status=dead |archive-url=https://web.archive.org/web/20130524213250/http://scienceindex.com/stories/2068471/Possible_connection_between_imidaclopridinduced_changes_in_rice_gene_transcription_profiles_and_susceptibility_to_the_brown_plant_hopperNilaparvatalugensStl_Hemiptera_Delphacidae.html |archive-date=24 May 2013 }}

Diamides selectively activate insect ryanodine receptors (RyR), which are large calcium release channels present in cardiac and skeletal muscle,{{Cite book |last1=Nauen |first1=Ralf |title=Advances in Insect Control and Resistance Management |last2=Steinbach |first2=Denise |date=27 August 2016 |publisher=Springer |isbn=978-3-319-31800-4 |editor-last=Horowitz |editor-first=A. Rami |location=Cham |publication-date=26 August 2016 |pages=219–240 |chapter=Resistance to Diamide Insecticides in Lepidopteran Pests |doi=10.1007/978-3-319-31800-4_12 |editor-last2=Ishaaya |editor-first2=Isaac |chapter-url=https://doi.org/10.1007/978-3-319-31800-4_12}} leading to the loss of calcium crucial for biological processes. This causes insects to act lethargic, stop feeding, and eventually die.{{Cite journal |last1=Du |first1=Shaoqing |last2=Hu |first2=Xueping |date=February 15, 2023 |title=Comprehensive Overview of Diamide Derivatives Acting as Ryanodine Receptor Activators |url=https://pubs.acs.org/doi/abs/10.1021/acs.jafc.2c08414 |journal=Journal of Agricultural and Food Chemistry |volume=71 |issue=8 |pages=3620–3638 |doi=10.1021/acs.jafc.2c08414 |pmid=36791236|bibcode=2023JAFC...71.3620D }} The first insecticide from this class to be registered was flubendiamide.

{{main| Biopesticide}}

The EU defines biopesticides as "a form of pesticide based on micro-organisms or natural products".{{Cite web |last= |first= |date=18 December 2008 |title=Encouraging innovation in biopesticide development |url=http://ec.europa.eu/environment/integration/research/newsalert/pdf/134na5.pdf |url-status=dead |archive-url=https://web.archive.org/web/20120515143828/http://ec.europa.eu/environment/integration/research/newsalert/pdf/134na5.pdf |archive-date=15 May 2012 |access-date=20 April 2012 |website= |publisher=European Commission DG ENV |type=News alert |id=Issue 134}} The US EPA defines biopesticides as “certain types of pesticides derived from such natural materials as animals, plants, bacteria, and certain minerals”.{{Cite web |date=18 October 2023 |title=What are Biopesticides? |url=https://www.epa.gov/ingredients-used-pesticide-products/what-are-biopesticides |access-date=9 Oct 2024 |website=United States Environmental Protection Agency}} Microorganisms that control pests may also be categorised as biological pest control agents together with larger organisms such as parasitic insects, entomopathic nematodes etc. Natural products may also be categorised as chemical insecticides.

The US EPA describes three types of biopesticide. Biochemical pesticides (meaning bio-derived chemicals), which are naturally occurring substances that control pests by non-toxic mechanisms. Microbial pesticides consisting of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Plant-Incorporated-Protectants (PIPs) are pesticidal substances that plants produce from genetic material that has been added to the plant (thus producing transgenic crops).

The global bio-insecticide market was estimated to be less than 10% of the total insecticide market.{{Cite journal |last=Marrone |first=Pamela G. |year=2024 |title=Status of the biopesticide market and prospects for new bioherbicides. |url=https://doi.org/10.1002/ps.7403 |journal=Pest Management Science |volume=80 |issue=1 |pages=81–86|doi=10.1002/ps.7403 |pmid=36765405 }} The bio-insecticide market is dominated by microbials.{{Cite book |last1=Glare |first1=T.R. |title=Microbial Control of Insect and Mite Pests |last2=Jurat-Fuentes |first2=J.-L. |last3=O’Callaghan |first3=M |publisher=Academic Press |year=2017 |isbn=9780128035276 |editor-last=Lacey |editor-first=Lawrence A. |pages=47–67 |chapter=Chapter 4 - Basic and Applied Research: Entomopathogenic Bacteria |doi=10.1016/B978-0-12-803527-6.00004-4 |chapter-url=https://doi.org/10.1016/B978-0-12-803527-6.00004-4}} The bio-insecticide market is growing more that 10% yearly, which is a higher growth than the total insecticide market, mainly due to the increase in organic farming and IPM, and also due to benevolent government policies.

Biopesticides are regarded by the US and European authorities as posing fewer risks of environmental and mammalian toxicity. Biopesticides are more than 10 x (often 100 x) cheaper and 3 x faster to register than synthetic pesticides.

There is a wide variety of biological insecticides with differing attributes, but in general the following has been described.{{Cite journal |last1=Mihăiță |first1=Daraban Gabriel |last2=Hlihor |first2=Raluca-Maria |last3=Suteu |first3=Daniela |year=2023 |title=Pesticides vs. Biopesticides: From Pest Management to Toxicity and Impacts on the Environment and Human Health |journal=Toxics |volume=11 |issue=12 |pages=983|doi=10.3390/toxics11120983 |doi-access=free |pmid=38133384 |pmc=10748064 }}{{Cite web |date=5 September 2024 |title=Advantages and Disadvantages of Biological Control |url=https://isam.education/en/advantages-and-disadvantages-of-biological-control/ |access-date=12 October 2024 |website=INTERNATIONAL SCHOOL OF AGRI MANAGEMENT S.L}}

They are easier, faster and cheaper to register, usually with lower mammalian toxicity. They are more specific, and thus preserve beneficial insects and biodiversity in general. This makes them compatible with IPM regimes. They degrade rapidly cause less impact on the environment. They have a shorter withholding period.

The spectrum of control is narrow. They are less effective and prone to adverse ambient conditions. They degrade rapidly and are thus less persistent. They are slower to act. They are more expensive, have a shorter shelf-life, and are more difficult to source. They require more specialised knowledge to use.

Most or all plants produce chemical insecticides to stop insects eating them. Extracts and purified chemicals from thousands of plants have been shown to be insecticidal, however only a few are used in agriculture.{{Cite journal |last=Isman |first=Murray B. |date=2020 |title=Botanical Insecticides in the Twenty-First Century—Fulfilling Their Promise? |url=https://doi.org/10.1146/annurev-ento-011019-025010 |journal=Annual Review of Entomology |volume=65 |pages=233–249|doi=10.1146/annurev-ento-011019-025010 |pmid=31594414 }} In the USA 13 are registered for use, in the EU 6. In Korea, where it is easier to register botanical pesticides, 38 are used. Most used are neem oil, chenopodium, pyrethrins, and azadirachtin. Many botanical insecticides used in past decades (e.g. rotenone, nicotine, ryanodine) have been banned because of their toxicity.

The first transgenic crop, which incorporated an insecticidal PIP, contained a gene for the CRY toxin from Bacillus thuringiensis (B.t.) and was introduced in 1997.{{Cite book |last1=Barry |first1=Jennifer K. |title=Advances in Insect Physiology Volume 65 |last2=Simmons |first2=Carl R. |last3=Nelson |first3=Mark E |publisher=Elsevier |year=2023 |isbn=9780323954662 |editor-last=Jurat-Fuentes |editor-first=Juan Luis |pages=185–233 |chapter=Chapter Five - Beyond Bacillus thuringiensis: New insecticidal proteins with potential applications in agriculture |doi=10.1016/bs.aiip.2023.09.004}} For the next ca 25 years the only insecticidal agents used in GMOs were the CRY and VIP toxins from various strains of B.t, which control a wide number of insect types. These are widely used with > 100 million hectares planted with B.t. modified crops in 2019. Since 2020 several novel agents have been engineered into plants and approved.  ipd072Aa from Pseudomonas chlororaphis, ipd079Ea from Ophioglossum pendulum, and mpp75Aa1.1 from Brevibacillus laterosporus code for protein toxins.{{Cite web |date=2024 |title=International Service for the Acquisition of Agri-biotech Applications (ISAAA) |url=https://www.isaaa.org/ |access-date=9 October 2024 |website=International Service for the Acquisition of Agri-biotech Applications (ISAAA)}} The trait dvsnf7 is an RNAi agent consisting of a double-stranded RNA transcript containing a 240 bp fragment of the WCR Snf7 gene of the western corn rootworm (Diabrotica virgifera virgifera).{{Cite book |last1=Vélez |first1=Ana M. |title=Advances in Insect Physiology |last2=Narva |first2=Ken |last3=Darlington |first3=Molly |last4=Mishra |first4=Swati |last5=Hellmann |first5=Christoph |last6=Rodrigues |first6=Thais B. |last7=Duman-Scheel |first7=Molly |last8=Palli |first8=Subba Reddy |last9=Jurat-Fuentes |first9=Juan Luis |publisher=Academic Press |year=2023 |isbn=9780323954662 |editor-last=Jurat-Fuentes |editor-first=Juan Luis |volume=65 |pages=1–54 |chapter=Chapter One - Insecticidal proteins and RNAi in the control of insects |doi=10.1016/bs.aiip.2023.09.007}}

RNA interference (RNAi) uses segments of RNA to fatally silence crucial insect genes.{{cite journal | last1=Zhu | first1=Kun Yan | last2=Palli | first2=Subba Reddy | title=Mechanisms, Applications, and Challenges of Insect RNA Interference | journal=Annual Review of Entomology | publisher=Annual Reviews | volume=65 | issue=1 | date=2020-01-07 | issn=0066-4170 | doi=10.1146/annurev-ento-011019-025224 | pages=293–311| pmid=31610134 | s2cid=204702574 | pmc=9939233 }} In 2024 two uses of RNAi have been registered by the authorities for use: Genetic modification of a crop to introduce a gene coding for an RNAi fragment, and spraying double stranded RNA fragments onto a field. Monsanto introduced the trait DvSnf7 which expresses a double-stranded RNA transcript containing a 240 bp fragment of the WCR Snf7 gene of the Western Corn Rootworm. GreenLight Biosciences introduced Ledprona, a formulation of double stranded RNA as a spray for potato fields. It targets the essential gene for proteasome subunit beta type-5 (PSMB5) in the Colorado potato beetle.

Spider venoms contain many, often hundreds, of insecticidally active toxins. Many are proteins that attack the nervous system of the insect.{{Cite journal |last=King |first=Glenn F |year=2019 |title=Tying pest insects in knots: the deployment of spider-venom-derived knottins as bioinsecticides |url=https://doi.org/10.1002/ps.5452 |journal=Pest Manag. Sci. |volume=75 |issue=9 |pages=2437–2445 |doi=10.1002/ps.5452|pmid=31025461 }} Vestaron introduced for agricultural use a spray formulation of GS-omega/kappa-Hxtx-Hv1a (HXTX), derived from the venom of the Australian blue mountain funnel web spider (Hadronyche versuta). HXTX acts by allosterically (site II) modifying the nicotinic acetylcholine receptor (IRAC group 32).{{Cite journal |last=Windley |first=Monique J. |last2=Vetter |first2=Irina |last3=Lewis |first3=Richard J. |last4=Nicholson |first4=Graham M. |date=2017 |title=Lethal effects of an insecticidal spider venom peptide involve positive allosteric modulation of insect nicotinic acetylcholine receptors |url=https://doi.org/10.1016/j.neuropharm.2017.04.008 |journal=Neuropharmacology |volume=127 |pages=224-242 |issn=0028-3908}}

Entomopathic bacteria can be mass-produced. The most widely used is Bacillus thuringiensis (B.t.), used since decades. There are several strains used with different applications against lepidoptera, coleoptera and diptera. Also used are Lysinibacillus sphaericus, Burkholderia spp, and Wolbachia pipientis. Avermectins and spinosyns are bacterial metabolites, mass-produced by fermentation and used as insecticides. The toxins from B.t. have been incorporated into plants through genetic engineering.

Entomopathic fungi have been used since 1965 for agricultural use. Hundreds of strains are now in use. They often kill a broad range of insect species. Most strains are from Beauveria, Metarhizium, Cordyceps and Akanthomyces species.{{Cite journal |last1=Jiang |first1=Y. |last2=Wang |first2=J. |year=2023 |title=The Registration Situation and Use of Mycopesticides in the World |journal=J. Fungi |volume=9 |issue=9 |pages=940 |doi=10.3390/jof9090940|doi-access=free |pmid=37755048 |pmc=10532538 }}

Of the many types of entomopathic viruses, only baculaviruses are used commercially, and are each specific for their target insect. They have to be grown on insects, so their production is labour-intensive.{{Cite book |last1=Nikhil Raj |first1=M. |title=New and Future Developments in Microbial Biotechnology and Bioengineering |last2=Samal |first2=Ipsita |last3=Paschapur |first3=Amit |last4=Subbanna |first4=A.R.N.S. |publisher=Elsevier |year=2022 |isbn=9780323855792 |editor-last=Bahadur |editor-first=Harikesh |pages=47–72 |chapter=Chapter 3 - Entomopathogenic viruses and their potential role in sustainable pest management |doi=10.1016/B978-0-323-85579-2.00015-0 |chapter-url=https://doi.org/10.1016/B978-0-323-85579-2.00015-0}}

Some insecticides kill or harm other creatures in addition to those they are intended to kill. For example, birds may be poisoned when they eat food that was recently sprayed with insecticides or when they mistake an insecticide granule on the ground for food and eat it.{{Cite web |last1=Palmer |first1=W.E. |last2=Bromley |first2=P.T. |last3=Brandenburg |first3=R.L. |title=Integrated Pest Management {{!}} NC State Extension |url=https://ipm.ces.ncsu.edu/ |access-date=14 October 2007 |website=North Carolina State Extension}} Sprayed insecticide may drift from the area to which it is applied and into wildlife areas, especially when it is sprayed aerially.

DDT was the first organic insecticide. It was introduced during WW2, and was widely used. One use was vector control and it was sprayed on open water. It degrades slowly in the environment, and it is lipophilic (fat soluble). It became the first global pollutant, and the first pollutant to accumulate{{cite book |last1=Castro |first1=Peter |title=Marine Biology |last2=Huber |first2=Michael E. |date=2010 |publisher=McGraw-Hill Companies Inc. |isbn=978-0-07-352416-0 |edition=8th |location=New York |oclc=488863548}} and magnify in the food chain.Pesticide Usage in the United States: History, Benefits, Risks, and Trends; Bulletin 1121, November 2000, K.S. Delaplane, Cooperative Extension Service, The University of Georgia College of Agricultural and Environmental Sciences {{cite web |title=Pesticide Usage in the United States: History, Benefits, Risks, and Trends |url=http://pubs.caes.uga.edu/caespubs/pubs/PDF/B1121.pdf |url-status=dead |archive-url=https://web.archive.org/web/20100613142901/http://pubs.caes.uga.edu/caespubs/pubs/PDF/B1121.pdf |archive-date=2010-06-13 |access-date=2012-11-10}}{{Cite thesis |last=Quinn |first=Amie L. |title=The impacts of agricultural chemicals and temperature on the physiological stress response in fish |type=MSc Thesis |publisher=University of Lethbridge |url=http://opus.uleth.ca/handle/10133/676 |year=2007 |location=Lethbridge}} During the 1950s and 1960s these very undesirable side effects were recognized, and after some often contentious discussion, DDT was banned in many countries in the 1960s and 1970s. Finally in 2001 DDT and all other persistent insecticides were banned via the Stockholm Convention.{{Cite web |date=2024 |title=Stockholm Convention on Persistent Organic Pollutants (POPs) |url=https://www.pops.int/ |access-date=6 October 2024 |website=Stockholm Convention on Persistent Organic Pollutants}}{{cite web |date=April 2005 |title=Ridding The World of Pops: A Guide to the Stockholm Convention on Persistent Organic Pollutants |url=http://www.pops.int/documents/guidance/beg_guide.pdf |archive-url=https://web.archive.org/web/20170315065236/http://www.pops.int/documents/guidance/beg_guide.pdf |archive-date=15 March 2017 |access-date=5 February 2017 |publisher=United Nations Environment Programme}} Since many decades the authorities require new insecticides to degrade in the environment and not to bioaccumulate.{{Cite web |date=19 August 2024 |title=Pesticide Registration |url=https://www.epa.gov/pesticide-registration |access-date=16 October 2024 |website=United States Environmental Protection Agency}}

Solid bait and liquid insecticides, especially if improperly applied in a location, get moved by water flow. Often, this happens through nonpoint sources where runoff carries insecticides in to larger bodies of water. As snow melts and rainfall moves over and through the ground, the water picks applied insecticides and deposits them in to larger bodies of water, rivers, wetlands, underground sources of previously potable water, and percolates in to watersheds.{{Cite web|url=https://www.epa.gov/sites/production/files/2015-09/documents/ag_runoff_fact_sheet.pdf|title=Protecting Water Quality from Agricultural Runoff|last=Environmental Protection Agency|date=2005|website=EPA.gov|access-date=2019-11-19}} This runoff and percolation of insecticides can effect the quality of water sources, harming the natural ecology and thus, indirectly effect human populations through biomagnification and bioaccumulation.

Both number of insects and number of insect species have declined dramatically and continuously over past decades, causing much concern.{{Cite journal |last=Wagner |first=David L. |date=14 October 2019 |title=Insect Declines in the Anthropocene |journal=Annu. Rev. Entomol. |volume=65 |pages=457–480|doi=10.1146/annurev-ento-011019-025151 |doi-access=free |pmid=31610138 }}{{Cite journal |last1=Sánchez-Bayo |first1=Francisco |last2=Wyckhuys |first2=Kris A.G. |date=2019 |title=Worldwide decline of the entomofauna: A review of its drivers |url=https://doi.org/10.1016/j.biocon.2019.01.020 |journal=Biol. Conserv. |volume=232 |issue=April |pages=8–27 |doi=10.1016/j.biocon.2019.01.020 |bibcode=2019BCons.232....8S |via=Elsevier Science Direct}}{{Cite journal |last=van der Sluijs |first=Jeroen. P. |date=October 2020 |title=Insect decline, an emerging global environmental risk |url=https://doi.org/10.1016/j.cosust.2020.08.012 |journal=Curr. Opin. Environ. Sustain. |volume=46 |issue=October |pages=39–42 |doi=10.1016/j.cosust.2020.08.012 |bibcode=2020COES...46...39V |via=Elsevier Science Direct|hdl=11250/2764289 |hdl-access=free }} Many causes are proposed to contribute to this decline, the most agreed upon are loss of habitat, intensification of farming practices, and insecticide usage. Domestic bees were declining some years ago{{cite journal |last=Oldroyd |first=B.P. |year=2007 |title=What's Killing American Honey Bees? |journal=PLOS Biology |volume=5 |issue=6 |pages=e168 |doi=10.1371/journal.pbio.0050168 |pmc=1892840 |pmid=17564497 |doi-access=free}} but population and number of colonies have now risen both in the USA{{Cite web |title=Table 21. Colonies of Honey Bees - Inventory and Honey Sales: 2022 and 2017. |url=https://www.nass.usda.gov/Publications/AgCensus/2022/Full_Report/Volume_1,_Chapter_2_US_State_Level/st99_2_021_021.pdf |access-date=12 November 2024 |website=USDA National Agricultural Statistics Service Census of Agriculture}} and worldwide.{{Cite web |date=2 March 2023 |title=Bee colonies: Worldwide population on the rise |url=https://www.destatis.de/EN/Themes/Countries-Regions/International-Statistics/Data-Topic/AgricultureForestryFisheries/Bees.html |access-date=12 November 2023 |website=Federal Statistical Office of Germany}} Wild species of bees are still declining.

Besides the effects of direct consumption of insecticides, populations of insectivorous birds decline due to the collapse of their prey populations. Spraying of especially wheat and corn in Europe is believed to have caused an 80 per cent decline in flying insects, which in turn has reduced local bird populations by one to two thirds.{{cite web|title=Catastrophic collapse in farmland bird populations across France|url=https://www.birdguides.com/news/catastrophic-collapse-in-farmland-bird-populations-across-france/|date=21 March 2018|publisher=BirdGuides|access-date=27 March 2018}}

Instead of using chemical insecticides to avoid crop damage caused by insects, there are many alternative options available now that can protect farmers from major economic losses.{{Cite journal |last=Aidley |first=David |date=Summer 1976 |title=Alternatives to insecticides |journal=Science Progress |volume=63 |issue=250 |pages=293–303 |jstor=43420363 |pmid=1064167 }} Some of them are:

1. Breeding crops resistant, or at least less susceptible, to pest attacks.{{Cite book|title=Plant Breeding for Pest and Disease Resistance|last=Russell|first=GE|publisher=Elsevier|year=1978|isbn=978-0-408-10613-9}}
2. Releasing predators, parasitoids, or pathogens to control pest populations as a form of biological control.{{Cite web|url=http://ipm.ucanr.edu/PMG/PESTNOTES/pn74140.html|title=Biological Control and Natural Enemies of Invertebrates Management Guidelines--UC IPM|website=ipm.ucanr.edu|access-date=2018-12-12}}
3. Chemical control like releasing pheromones into the field to confuse the insects into not being able to find mates and reproduce.{{Cite web|url=http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=-80|title=Mating Disruption|website=jenny.tfrec.wsu.edu|access-date=2018-12-12|archive-date=2018-06-12|archive-url=https://web.archive.org/web/20180612165450/http://jenny.tfrec.wsu.edu/opm/displaySpecies.php?pn=-80|url-status=dead}}
4. Integrated Pest Management: using multiple techniques in tandem to achieve optimal results.{{Cite web|url=https://nysipm.cornell.edu/about/defining-ipm/|title=Defining IPM {{!}} New York State Integrated Pest Management|website=nysipm.cornell.edu|access-date=2018-12-12}}
5. Push-pull technique: intercropping with a "push" crop that repels the pest, and planting a "pull" crop on the boundary that attracts and traps it.{{Cite journal|last1=Cook|first1=Samantha M.|last2=Khan|first2=Zeyaur R.|last3=Pickett|first3=John A.|date=2007|title=The use of push-pull strategies in integrated pest management|journal=Annual Review of Entomology|volume=52|pages=375–400|doi=10.1146/annurev.ento.52.110405.091407|issn=0066-4170|pmid=16968206}}

Source:

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{{See also|Category:Organochloride insecticides}}

• Aldrin
• Chlordane
• Chlordecone
• DDT
• Dieldrin
• Endosulfan
• Endrin
• Heptachlor
• Hexachlorobenzene
• Lindane (gamma-hexachlorocyclohexane)
• Methoxychlor
• Mirex
• Pentachlorophenol
• TDE

{{See also|Category:Organophosphate insecticides}}

• Acephate
• Azinphos-methyl
• Bensulide
• Chlorethoxyfos
• Chlorpyrifos
• Chlorpyriphos-methyl
• Diazinon
• Dichlorvos (DDVP)
• Dicrotophos
• Dimethoate
• Disulfoton
• Ethoprop
• Fenamiphos
• Fenitrothion
• Fenthion
• Fosthiazate
• Malathion
• Methamidophos
• Methidathion
• Mevinphos
• Monocrotophos
• Naled
• Omethoate
• Oxydemeton-methyl
• Parathion
• Parathion-methyl
• Phorate
• Phosalone
• Phosmet
• Phostebupirim
• Phoxim
• Pirimiphos-methyl
• Profenofos
• Terbufos
• Tetrachlorvinphos
• Tribufos
• Trichlorfon

• Aldicarb
• Bendiocarb
• Carbofuran
• Carbaryl
• Dioxacarb
• Fenobucarb
• Fenoxycarb
• Isoprocarb
• Methomyl
• Oxamyl
• Propoxur
• 2-(1-Methylpropyl)phenyl methylcarbamate

• Allethrin
• Bifenthrin
• Cyhalothrin, Lambda-cyhalothrin
• Cypermethrin
• Cyfluthrin
• Deltamethrin
• Etofenprox
• Fenvalerate
• Permethrin
• Phenothrin
• Prallethrin
• Resmethrin
• Tetramethrin
• Tralomethrin
• Transfluthrin

• Acetamiprid
• Clothianidin
• Dinotefuran
• Imidacloprid
• Nithiazine
• Thiacloprid
• Thiamethoxam

• Chlorantraniliprole
• Cyantraniliprole
• Flubendiamide

• Benzoylureas
• Diflubenzuron
• Flufenoxuron
• Cyromazine
• Methoprene
• Hydroprene
• Tebufenozide

• Anabasine
• Anethole (mosquito larvae)
• Annonin
• Asimina (pawpaw tree seeds) for lice
• Azadirachtin
• Caffeine
• Carapa
• Cinnamaldehyde (very effective for killing mosquito larvae){{Cite web |title=Cornelia Dick-Pfaff: Wohlriechender Mückentod, 19.07.2004 |website=www.wissenschaft.de |url=http://www.wissenschaft.de/wissen/news/243037.html |url-status=dead |access-date=2008-08-04 |archive-date=2006-03-24 |archive-url=https://web.archive.org/web/20060324043451/http://www.wissenschaft.de/wissen/news/243037.html }}
• Cinnamon leaf oil (very effective for killing mosquito larvae){{cite web |title=Cinnamon Oil Kills Mosquitoes |url=https://www.sciencedaily.com/releases/2004/07/040716081706.htm |publisher=www.sciencedaily.com |access-date=5 August 2008}}
• Cinnamyl acetate (kills mosquito larvae)
• Citral
• Citronellol
• Deguelin
• Derris (active ingredient is rotenone)
• Desmodium caudatum (leaves and roots)
• Eucalyptol{{cite book |title=Comprehensive natural products chemistry |date=1999 |publisher=Elsevier |location=Amsterdam |isbn=978-0-08-091283-7 |page=306 |edition=1st}}
• Eugenol (mosquito larvae)
• Hinokitiol{{cite journal |last1=Bentley |first1=Ronald |title=A fresh look at natural tropolonoids |journal=Nat. Prod. Rep. |date=2008 |volume=25 |issue=1 |pages=118–138 |doi=10.1039/B711474E |pmid=18250899 }}
• Ivermectin
• Limonene{{cite web |title=R.E.D. FACTS: Limonene |url=https://archive.epa.gov/pesticides/reregistration/web/pdf/3083fact.pdf |publisher=EPA – United States Environmental Protection Agency}}
• Linalool{{cite web |title=BIOPESTICIDES REGISTRATION ACTION DOCUMENT |publisher=U.S. Environmental Protection Agency |url=https://www3.epa.gov/pesticides/chem_search/reg_actions/registration/decision_PC-128838_10-Jun-08.pdf}}
• Menthol
• Myristicin
• Neem (Azadirachtin)
• Nicotine
• Nootkatone{{cite web |last1=US EPA |first1=OCSPP |title=Nootkatone Now Registered by EPA |url=https://www.epa.gov/pesticides/nootkatone-now-registered-epa |website=US EPA |language=en |date=10 August 2020}}
• Peganum harmala, seeds (smoke from), root
• Oregano oil kills Rhyzopertha dominica{{cite web| url=https://www.sciencedaily.com/releases/2008/05/080522072339.htm| title=Oregano Oil Works As Well As Synthetic Insecticides To Tackle Common Beetle Pest| publisher=www.sciencedaily.com| access-date=23 May 2008}} (bug found in stored cereal)
• Pyrethrum
• Quassia (South American plant genus)
• Ryanodine
• Spinosad AKA Spinosyn A
• Spinosyn D
• Tetranortriterpenoid
• Thymol (controls varroa mites in bee colonies){{cite news|title=Almond farmers seek healthy bees | work=BBC News | date=2006-03-08 |url=http://news.bbc.co.uk/2/hi/science/nature/4780034.stm | access-date=2010-01-05}}

• Bacillus sphaericus
• Bacillus thuringiensis
• Bacillus thuringiensis aizawi{{cite web |title=Bacteria |website=Biological Control |publisher=Cornell University |url=http://www.biocontrol.entomology.cornell.edu/pathogens/bacteria.html |url-status=dead |archive-date=2011-09-09 |archive-url=https://web.archive.org/web/20110909110525/http://www.biocontrol.entomology.cornell.edu/pathogens/bacteria.html}}
• Bacillus thuringiensis israelensis
• Bacillus thuringiensis kurstaki
• Bacillus thuringiensis tenebrionis
• Nuclear Polyhedrosis virus
• Granulovirus
• Lecanicillium lecanii

• Diatomaceous earth
• Borax
• Boric Acid

{{div col end}}

• Fogger
• Index of pesticide articles
• Insecticide Resistance Action Committee
• Integrated pest management
• Pesticide application
• Sterile insect technique

{{Reflist|30em|refs=

{{cite web | title=Interactive MoA Classification | website=Insecticide Resistance Action Committee | date=2020-09-16 | url=http://irac-online.org/modes-of-action/ | access-date=2021-04-01}}

}}

• {{cite journal | author = McWilliams James E | year = 2008| title = 'The Horizon Opened Up Very Greatly': Leland O. Howard and the Transition to Chemical Insecticides in the United States, 1894–1927 | journal = Agricultural History | volume = 82 | issue = 4| pages = 468–95 | doi = 10.3098/ah.2008.82.4.468 | pmid = 19266680}}

{{Americana Poster}}

{{Wiktionary|insecticide}}

{{Commons category}}

• [http://www.insectbuzz.com/ InsectBuzz.com] {{Webarchive|url=https://web.archive.org/web/20101211112244/http://insectbuzz.com/ |date=2010-12-11 }} - Daily updated news on insects and their relatives, including information on insecticides and their alternatives
• [http://www.dropdata.org International Pesticide Application Research Centre (IPARC)]
• [http://www.pestworld.org/ Pestworld.org] – Official site of the National Pest Management Association
• Streaming online video about efforts to reduce insecticide use in rice in Bangladesh. [https://web.archive.org/web/20061102001739/http://www.irri.org/videos/LITE-research.wmv on Windows Media Player], [https://web.archive.org/web/20061102001718/http://www.irri.org/videos/LITE-research.rm on RealPlayer]
• [http://grounds-mag.com/mag/grounds_maintenance_insecticides_work/index.html How Insecticides Work] {{Webarchive|url=https://web.archive.org/web/20130903022817/http://grounds-mag.com/mag/grounds_maintenance_insecticides_work/index.html |date=2013-09-03 }} – Has a thorough explanation on how insecticides work.
• [http://www.ipm.ucdavis.edu/WATER/U/alternative.html University of California Integrated pest management program]
• [https://web.archive.org/web/20091126070818/http://www.msue.msu.edu/objects/content_revision/download.cfm/revision_id.496061/workspace_id.-4/01500536.html/ Using Insecticides], Michigan State University Extension
• Example of Insecticide application in the [http://www.zen-garden.org/html/page_control.htm Tsubo-en Zen garden] {{Webarchive|url=https://web.archive.org/web/20120602083834/http://www.zen-garden.org/html/page_control.htm |date=2012-06-02 }} (Japanese dry rock garden) in Lelystad, The Netherlands.
• {{cite web | title=IRAC | website=Insecticide Resistance Action Committee | date=2021-03-01 | url=http://irac-online.org/ | access-date=2021-04-02}}

{{insecticides|state=open}}

{{pesticides}}

{{Authority control}}

Category:Biocides