Pyrethrin affects an insect's nervous system through a deadly toxic effect. Almost immediately upon contact with this compound, the insect dies from a form of paralysis. This effect is what makes pyrethrin a highly effective insecticide.

What does pyrethrin do to insects?

Pyrethrins excite the nervous system of insects that touch or eat it. This quickly leads to paralysis and ultimately their death. Pyrethrins are often mixed with another chemical to increase their effect. This second chemical is known as a synergist.

How do pyrethroids kill insects?

Pyrethrins delay the closure of voltage-gated sodium channels in the nerve cells of insects, resulting in repeated and extended nerve firings. This hyperexcitation causes the death of the insect due to loss of motor coordination and paralysis.