Chlorantraniliprole (Chlorantraniliprole)

Chlorantraniliprole is a systemic and contact insecticide belonging to the anthranilic diamide class, representing a mechanism of action that acts specifically on the ryanodine receptors of insects. This active ingredient provides control of Lepidoptera and some Coleoptera, presenting high selectivity for arthropods and low toxicity for mammals.

Chlorantraniliprole was developed by DuPont and commercially launched in 2007 under the trade name Rynaxypyr. It represents the first molecule in the anthranilic diamide class, introducing a new mechanism of action into the insecticide market.

Common name (ISO): Chlorantraniliprole (Chlorantraniliprole)

Official chemical name: 3-bromo-N-[4-cloro-2-metil-6-[(metilamino)carbonil]fenil]-1-(3-cloropiridin-2-il)-1H-pirazol-5-carboxamida

Gross chemical formula: C₁₈H₁₄BrCl₂N₅O₂

Number CAS: 500008-45-7

Chemical class: anthranilic diamides

IRAC Group: Group 28 - ryanodine receptor modulators

Mode of action

Chlorantraniliprole acts as a selective agonist of ryanodine receptors (RyR) present in insect muscle cells. These receptors function as intracellular calcium channels responsible for regulating the release of Ca²⁺ from the sarcoplasmic reticulum.

The binding of the active ingredient to ryanodine receptors causes the uncontrolled opening of these channels, resulting in the excessive release of intracellular calcium. This calcium imbalance compromises normal muscle contractions, leading to muscle paralysis and eventual death of the insect.

Characteristic symptoms: Insects exposed to chlorantraniliprole initially exhibit reduced feeding, followed by lethargy, progressive muscle paralysis, regurgitation, and irregular muscle contractions. Affected lepidopterans demonstrate uncoordinated jaw movements and cessation of feeding within the first few hours after exposure.

Time for symptoms to appear: The first symptoms appear between 1-4 hours after exposure, with complete cessation of feeding typically occurring within 2-4 hours. Mortality usually occurs between 24-72 hours, depending on the species, developmental stage and dose applied.

Efficiently controlled species:

• Lepidoptera: Spodoptera frugiperda (fall armyworm), Helicoverpa armigera (apple caterpillar), Chrysodeixis includens (false measuring worm), Anticarsia gemmatalis (soybean caterpillar), Heliothis virescens (cotton apple caterpillar)

• Coleoptera: Diabrotica speciosa (little cow), Phyllophaga cuyabana (choir)

• Diptera: some species of leafminer flies

• Thysanoptera: certain species of thrips

Partially controlled species:

• Older Lepidoptera (4th and 5th instars)

• Plutella xylostella in populations with a history of exposure

• Some species of spodoptera spp. in advanced stages of development

Tolerant or resistant species:

• Hemiptera (bugs, aphids, leafhoppers)

• Mites

• Lepidoptera with developed resistance to ryanodine receptors

• Insects with high detoxifying metabolism

Technical application recommendations

Recommended dose:

• Standard: 10-20 g ai/ha for most crops

• High pressure situations: 15-30 g ai/ha

• Foliar application: 5-15 mL/100L of spray

• Seed treatment: 0,25-0,75 mL/kg seed

Ideal time for application: Application should preferably be carried out at the beginning of the infestation, when the caterpillars are in the initial stages of development (1st to 3rd instars). For crops such as soybeans and corn, constant monitoring and application are recommended when the level of economic damage established for each pest is reached.

Ideal weather conditions:

• Temperature: 15-30 ° C

• Relative humidity: greater than 60%

• Wind speed: less than 10 km/h

• Absence of rain for at least 2 hours after application

• Avoid applications during the hottest hours of the day (10am-16pm)

Compatibility and mixtures

Chlorantraniliprole has good physical and chemical compatibility with most commonly used fungicides, herbicides and other insecticides. It is compatible with adjuvants such as spreaders, adhesives and mineral oils at recommended concentrations.

Common mixtures and their purposes:

• With triazole or strobilurin fungicides for simultaneous control of pests and diseases

• With post-emergence herbicides in sequential applications

• With insecticides from different groups (organophosphates, pyrethroids) to broaden the spectrum and manage resistance

• With foliar fertilizers for application optimization

Mixtures to avoid:

• Products with extremely alkaline pH (>9,0)

• Formulations with high copper concentration

• Broths with high saline concentration

• Mixing with growth regulators without prior compatibility testing

Resistance and resistance management

Cases of resistance have been reported in populations of Plutella xylostella (diamondbottle moth) in different regions of the world, including the Philippines, Thailand and some American states.

Populations of Tuta absoluta (tomato moth) also showed reduced sensitivity in some regions of South America and Europe.

Recent studies indicate possible development of resistance in populations of Spodoptera frugiperda with a history of intense selection pressure.

Recommendations for rotation of mechanisms of action:

• Alternate with insecticides from IRAC groups 1A/1B (organophosphates/carbamates)

• Use group 3A products (pyrethroids) in rotation

• Incorporate group 5 insecticides (spinosyns) into the program

• Consider products from group 22A (oxadiazines) as an alternative

Practical strategies for resistance management:

• Implement the "application window" concept, respecting minimum intervals of 21 days between applications

• Use full recommended doses, avoiding underdosing

• Carry out constant monitoring of pest populations

• Adopt integrated control practices including biological control

• Preserve refuge areas when possible

• Implement crop rotation to break the pest cycle

Agronomic efficiency

Conditions affecting effectiveness:

• Rain: Heavy rainfall within 2-4 hours of application may reduce effectiveness due to product washing off before complete absorption.

• Drought: severe water stress conditions can limit systemic uptake, reducing efficacy particularly in soil applications

• Temperature: high temperatures (>35°C) can accelerate product degradation and reduce its persistence

• Humidity: low relative humidity (<40%) can compromise foliar absorption

Among the advantages of chlorantraniliprole, we can mention: excellent selectivity for beneficial insects; long residual period (7-14 days); systemic and translaminar action; low toxicity for mammals; efficacy at low doses; and control of pests resistant to other chemical groups.

On the other hand, there are limitations: spectrum limited mainly to lepidopterans; higher cost compared to conventional insecticides; risk of developing resistance with intensive use; lower effectiveness against sucking insects.

Strategic positioning in agricultural systems:

• Soybean: use preferably to control soybean caterpillars (Anticarsia gemmatalis) and false measuring worm (Chrysodeixis includens) in the reproductive period, when pod protection is critical. Position as a rotation tool with other chemical groups.

• Corn: excellent option for controlling fall armyworm (Spodoptera frugiperda) in foliar applications or seed treatment. Particularly effective in production systems where there is pressure from multiple lepidopteran species.

• Cotton: strategic tool for controlling caterpillar complex, especially Helicoverpa armigera e Heliothis virescens. Recommended for applications during the period of flower bud and apple formation.

• Sugarcane: specific use for controlling borers, mainly Diatraea saccharalis, in integrated management programs. Application via aerial or ground spraying during critical periods of infestation.