I found this footage from April 2016 and wanted to get the word out about how bad this insecticide was for the lizards around my house. The trees had been sprayed with bifenthrin to stop a bug from killing them, and afterwards I started finding lizards twitching, stumbling around and eventually dying. While invertebrates may not feel pain, I have a feeling these poor little lizards did.

Pyrethroids affect the nervous system by interfering with sodium channels in nerve cells. Bifenthrin is a Type I pyrethroid, and poisoning can produce neurological effects including twitching, tremors, loss of coordination and paralysis - very much like what I was seeing in these lizards.

Temperature can also affect pyrethroid toxicity in reptiles. Lizards are ectotherms, and experimental studies have found markedly higher mortality from pyrethroid exposure at lower body temperatures. That helps explain why these chemicals can behave differently in reptiles than they do in mammals.

The following video explains the mode of action for these pyrethroids.

I don’t think I’ll hire anyone to spray the garden for anything ever again.

Sources