ReviewToxicological effects of pyrethroids on non-target aquatic insects

- Aquatic insects are highly sensitive to toxicological effect of pyrethroids.
- Susceptibility may be related to biochemical and physiological constraints.
- The susceptibility of aquatic organisms to pyrethroid insecticides is critical.
- Pyrethroids may also alter beneficial predator-prey relationships.
- More emphasis is needed on the standardization of pesticide bioassays.

The toxicological effects of pyrethroids on non-target aquatic insects are mediated by several modes of entry of pyrethroids into aquatic ecosystems, as well as the toxicological characteristics of particular pyrethroids under field conditions. Toxicokinetics, movement across the integument of aquatic insects, and the toxicodynamics of pyrethroids are discussed, and their physiological, symptomatic and ecological effects evaluated. The relationship between pyrethroid toxicity and insecticide uptake is not fully defined. Based on laboratory and field data, it is likely that the susceptibility of aquatic insects (vector and non-vector) is related to biochemical and physiological constraints associated with life in aquatic ecosystems. Understanding factors that influence aquatic insects susceptibility to pyrethroids is critical for the effective and safe use of these compounds in areas adjacent to aquatic environments.