Synthetic pyrethroids and pyrethrins (SP)

What do they treat?

Flies Ticks Lice

When using SPs to target a particular parasite, be aware that they will also treat any other of the above-mentioned parasites that are present. This can increase the development of pesticide resistance by all of these parasites each time a SP product is used.

Note: Very toxic to fish and to beneficial insects such as bees

How can they be administered?

A variety of application methods for administering pesticide products to cattle are in use.

Ear tags Spray on Pour-on Dip þ Powder Premises surface spray

  • Ear tags, spray on, pour-on and dips should be correctly applied to all cattle in a mob to ensure effective control.
  • Follow label instructions.

Resistance

Reported in: Flies Ticks

  • SP resistance has been detected in certain areas and once present it can build up very quickly.
  • Under-dosing will lead to poor pest control and may hasten the development of resistance to the chemical.

What is resistance?

Safety

Everyone working in the rural industry has a ‘duty of care’; a legal obligation to provide a safe workplace for everyone on the property.

  • SPs and pyrethrins are generally regarded as compounds of low-toxicity but can cause eye and skin irritation in some people.

Withholding

Withholding periods are mandatory with all registered veterinary products used to treat animals for internal and external parasites.

  • Always check the product label before use for specific withholding periods (WHP) and export slaughter interval (ESI) periods. Current ESI periods can be confirmed on the APVMA website.

Types of synthetic pyrethroids and pyrethrins

A guide to the different chemical actives and the pests they affect are in Table 1. See the Products Search Guides for FlyBoss, LiceBoss, WormBoss and TickBoss for the appropriate formulation and application method for your target pest. Note that combinations and mixtures of actives may improve treatment efficacy.

Table 1. Synthetic pyrethroids and pyrethrins, their actives combinations and mixtures and a summary of the targeted parasites for which formulations are registered for. Boxed check marks indicate the pest targeted by multiple actives.

Chemical

Pests targeted (may vary with formulation)

Worms

Flies

Ticks

Lice

Mites

Buffalo fly Stable fly

Premises flies*

Fly

strike

Cattle Paralysis Bush

SPs

 

   

 

 

 

 

Cyfluthrin

   

 

 

 

 

Beta-cyfluthrin

 

 

 

 

 

Lambda-cyhalothrin

   

 

 

 

 

Cyphenothrin

   

 

 

 

 

Alpha-cypermethrin

 

 

 

Zeta-cypermethrin

 

 

 

 

 

Deltamethrin

 

 

 

Esfenvalerate

 

 

 

 

 

 

Fenvalerate

 

 

 

 

 

 

Flumethrin

 

   

 

 

 

Permethrin

 

 

 

 

Delta-tetramethrin

 

 

 

 

 

 

Pyrethrins

 

 

 

 

 

Combination (all actives target boxed parasite)

 

 

 

 

 

 

 

Beta-cyfluthrin and imidacloprid

 

 

 

 

 

 

Cypermethrin and chlorfenvinphos

 

Buffalo fly  

 

 

Cattle and other ticks

 

Cyphenothrin and detla-tetramethrin

 

 

   

 

 

Deltamethrin and ethion

 

Buffalo fly

 

 

Cattle and bush tick

 

 

Pyrethrins and diazinon

 

 

 

 

 

 

*IRAC Mode of Action group 3A

What are they?

Synthetic pyrethroids are synthetically manufactured compounds with a molecular structure similar to naturally occurring pyrethrins. Natural pyrethrins are extracts from the flowers of certain plants which have insecticidal and repellent properties.

How do they work?

SPs have a broad spectrum of activity, they are non-systemic, very fast-acting pesticides that act by contact. Susceptible insects are knocked down and die very quickly. Many SPs and natural pyrethrins also have a repellent effect.

SPs affect the axons of nerves causing paralysis of target organisms by keeping sodium channels open in the nerve membranes. The resultant constant nerve excitement eventually causes insect paralysis. This toxic effect also occurs in vertebrates since the cellular membranes work in a similar manner.

Natural pyrethrins are unstable when exposed to sunlight limiting protection for animals to a few days at most.