Factors contributing to selective toxicity of pyrethroids
| Selectivity Factor | Mammals | Insects | Differences |
|---|---|---|---|
| Potency on nerve | |||
| Due to temperature dependence | Low (37°C) | High (25°C) | 5 |
| Due to intrinsic sensitivity | Low | High | 10 |
| Recovery | Fast | Slow | 5 |
| Detoxication rate | |||
| Due to enzymatic action | High | Low | 3 |
| Due to body size | High | Low | 3 |
Overall difference = 2250 (Song and Narahashi, 1996).