Etofenprox acts like a pyrethroid but is chemically an ether, not an ester. This distinction matters because it gives etofenprox significantly lower fish toxicity than true pyrethroids while maintaining similar insecticidal activity. Used in mosquito control, agriculture, and some consumer products.
Mosquitoes (adult and larval), rice pests, vegetable pests, stored product pests, flies, gnats. Broad-spectrum contact and ingestion insecticide effective against most flying and crawling insects.
Trebon (Mitsui Chemicals - the original brand), Zenivex (mosquito adulticide for public health programs), Vectobac plus etofenprox combinations, various agricultural formulations. Limited consumer products in the US.
Lower mammalian toxicity than most pyrethroids. The key advantage is dramatically reduced fish and aquatic toxicity compared to true pyrethroids like bifenthrin or permethrin. This makes it preferred for mosquito control programs near waterways.
Why not a pyrethroid: Despite acting exactly like a pyrethroid at the nerve level, etofenprox has a different chemical structure (ether vs ester bond). This structural difference is why fish can metabolize and detoxify it much more efficiently than true pyrethroids.
Mosquito control: Used as an adulticide in ULV (ultra-low volume) truck-mounted and aerial spray programs. Provides excellent mosquito knockdown with a better environmental profile than permethrin or sumithrin in aquatic-adjacent areas.
Cross-resistance: Because etofenprox targets the same sodium channel as pyrethroids, insects with pyrethroid resistance (kdr mutations) may also show reduced susceptibility to etofenprox. This limits its usefulness in areas with established pyrethroid resistance.