Acaricides classification

Classification of acaricides based on it's chemical nature

1. Classification of
AcaricidesBased on its
Chemical Nature
AaliyaAfroz
Ph. D. Scholar
Department of Entomology
Indira Gandhi KrishiVishwavidyalaya

2. Botanical Acaricides
a. Carvacrol:
vCarvacrolisanactiveingredientofessentialoilsfromdifferentplants,
mainlyfromoreganoandthymespecies.
vItposessesbiocidalactivityagainstmanyarthropodesoftheimportance
forveterinaryandhumanmedicine.
vCarvacrolactsasrepelent,larvicide,insecticideandacaricide.
vItactsagainstpestartropodessuchasthosethatserveasmechanicalor
biologicalvectorsformanycausalagentsofviral,bacterialandparasitic
diseasesforanimalsandhumans.
vTherefore,itmaybeusednotonlyinpestarthropodescontrolbutin
vectorbornediseasescontrol,too.

3. Mode of Action-
vCarvacrolinduceanimmediateneurotoxicityanditisreportedthat
hydrophobicityofcompoundsinfluencesthepenetrationthroughthecuticle
andpiperonylbutoxidesynergizedthetoxiceffects.
vCarvacrolalsoinhibitsacetylcholinesteraseandactsasanantagonistof
GABA,thus,inhibitingthechlorideuptakeintotheneuronthroughthe
chloridechannel.

4. b. Sanguinarine:
vSanguinarineis a toxic polycyclic ammonium ion.
vIt is extracted from some plants, including the bloodroot plant
(SanguinariaCanadensis).
Mode of Action-
Sanguinarineis a toxin that kills animal cells through itsactionon the
Na
+
/K
+
-ATPase transmembrane protein.

5. Bridged Diphenyl Acaricides
a. Dicofol:
v“Dicofolis used to kill crop-feeding mite pests such as the red spider
mite.
vIt is a contact poison which kills the pest after being ingested and picked
up from the surface of the crop.
vDicofolis chemically similar to DTT –C
14H
9Cl
5–which is lacking the
oxygen component of itsmiticiderelative.
Mode of Action-
vA non systemic, acaricideor miticidewith contact action.
vIt is an organochlorine that is a GABA-gated chloride channel
antagonist.

6. b. Benzyl Benzoate:
vBenzylbenzoateisabenzoateesterobtainedbytheformalcondensation
ofbenzoicacidwithbenzylalcohol.
vIthasbeenisolatedfromtheplantspeciesofthegenusPolyalthia.
vIthasaroleasascabicide,anacaricideandaplantmetabolite.
vItisabenzylesterandabenzoateester.

7. Mode of Action-
vBenzylbenzoateexertstoxiceffectsonthenervoussystemoftheparasite,
resultinginitsdeath.Itisalsotoxictomiteova,thoughitsexactmechanismof
actionisunknown.
vInvitro,benzylbenzoatehasbeenfoundtokilltheSarcoptesmitewithin5
minutes.

8. Carbamate Acaricides
a. Propoxur
vPropoxur(Baygon) is a carbamate non-systemic insecticide introduced in
1959 with a fast knockdown and long residual effect used against turf,
forestry, and household pests and fleas.
vIt is also used in pest control for other domestic animals, Anopheles
mosquitoes, ants, gypsy moths, and other agricultural pests.
Mode of Action-
Similar to other
carbamateinsecticides,propoxurinhibitsacetylcholinesterase, an enzyme
involved in neurotransmission, producing neurotoxic effects in insects
andnontarget organisms.

9. b. Carbaryl
vCarbarylis a chemical in the carbamate family used chiefly as an
insecticide.
vIt is a white crystalline solid commonly sold under the brand name Sevin.
Mode of Action-
vCarbaryldisrupts the normal functioning of the insect nervous system and
may cause toxicity by contact or ingestion.
vWhen the enzyme is inhibited, surplus acetylcholine builds up, resulting in
nervous system overstimulation.

10. DinitrophenolAcaricides
a. Dinopenton
Mode of Action:
vContact with protective and curative action.
vRespiration inhibitor.
vUncouplerof oxidative phosphorylation via disruption of proton gradient.

11. FormamidineAcaricides
a. Chlordimeform
vChlordimeformisacarboxamidine,aformamidineacaricideandamemberof
monochlorobenzenes.
vItismoderatelysolubleinwaterandhighlysolubleinmanyorganicsolvents.
vItisvolatile.
vUndernormalconditionsiswouldnotbeexpectedtoleachtogroundwater.
vItismoderatelypersistentinsoilsystemsbutwouldnotbeexpectedtopersist
inwatersystems.

12. Mode of Action:
vIt has a role as an antifeedant.
vIt is moderately toxic to mammals, a neurotoxin and has a high potential for
bio-concentration.
vIt is moderately toxic to birds and fish but less so to honeybees.
vAn acaricideused against many organophosphate and carbamate resistant
pests.
vIt acts as an uncoupling agent and monoamine oxidase inhibitor.
vBroad spectrum acaricidethat appears to interfere with the amine-mediated
control of nervous and endocrine systems.

13. b. Formetanate
Mode of Action:
vContact and stomach action.
vActs by inhibiting acetylcholinesterase.

14. Avermectines
Abamectin
Abamectinisusedtocontrolinsectandmitepestsofarangeof
agronomic,fruit,vegetableandornamentalcrops.

15. Mode of Action:
vTheystimulatethegamma-aminobutyricacid(GABA)system,achemical
“transmitter”producedatnerveendings,whichinhibitsbothnervetonerve
andnervetomusclecommunication.
vTheaffectedinsect/mitebecomesparalyzed,stopsfeeding,anddiesaftera
fewdays.

16. Milbemycinacaricides
Milbemectin:
An insecticide and acaricideeffective against all development stages of
mites and some other insects.
Mode of Action:
Contact and stomach action, acting on the targets nervous system

17. Mite Growth Regulators
a. Clofentezine
vIt is an acaricidethat is used in plant protection products for the control
of spider mites on a wide range of crops.
vIt acts primarily as an ovicide, but it has some activity against early motile
stages of mites.
Mode of Action:
Leading to inhibition of chitin biosynthesis.

18. b. Fluazuron
Insectgrowthregulatorandbroadspectrumantiparasiticsubstanceusedto
controlticksinlivestock,especiallycattle.
ModeofAction:
vChitinsynthesisinhibitor.
vTreatedimmatureticksareunabletomoulttothenextstage,andno
larvaewillhatchfromeggslaidbytreatedfemales.
vTheprinciplemodeofactionoffluazurononthecattle-tickisbyinhibition
ofchitinincorporationintotickcuticle.
vTheinhibitionispresumablyagainstenzymesinvolvedinthefinalstages
ofchitinsynthesis(Kempetal.,1990).

19. Organophosphorus Acaricides
a. Chlorfenvinphos
Chlorfenvinphosisthecommonnameofanorganophosphoruscompoundthat
waswidelyusedasaninsecticideandanacaricide.
ModeofAction:
vThetoxicityofchlorfenvinphosisprimarilycausedbyitsinhibition
ofcholinesteraseactivity.
vItreactswiththeacetylcholinebindingsitesofenzymesthathydrolyze
acetylcholine,therebypreventingtheircatalysisofthisreaction.

20. b. Dichlorvos
Mode of Action:
vDichlorvos,likeotherorganophosphateinsecticides,actson
acetylcholinesterase,associatedwiththenervoussystemsofinsects.
vEvidenceforothermodesofaction,applicabletohigheranimals,
havebeenpresented.
vItisclaimedtodamageDNAofarthropods.

21. PyrethroidAcaricides
a. Lambda cyhalothrin
Lambdacyhalothrinisasyntheticpyrethroidinsecticideand
acaricideusedtocontrolawiderangeofpestsinavarietyof
applications.
ModeofAction:
vAsoneofthepyrethroids,Lambdacyhalothrinaffectsthenervous
systemofanorganismbydisruptingthegatingmechanismofsodium
channelsthatareinvolvedinthegenerationandconductionofnerve
impulses.
vTemperatureinfluencesinsectparalysisandthetoxicityoflambda-
cyhalothrin.

22. b. Flumethrin
vFlumethrinisapyrethroidinsecticide.
vItisusedexternallyinveterinarymedicineagainstparasiticinsects
andticksoncattle,sheep,goats,horses,anddogs,andthetreatment
ofparasiticmitesinhoneybeecolonies.
vThepyrethroidflumethrinhasbeenregisteredforanimaluseasan
acaricidesince1986.

23. Mode of Action:
vItspharmacologicalactivityismediatedthroughvoltagegatedsodium
channelsinneuraltissuewhichitcausestoremainopenforlongerthan
physiologicallynormal,thusextendingtheperiodofsodiuminflux.