What is the difference between Pyrethrins and Pyrethroids?
Pyrethrins (pyrethrum) are natural insecticides which are derived from the chrysanthemum flower. Pyrethroids are synthetic (man-made) insecticides which contain petroleum distillates. Pyrethroids are typically used in misting system applications such as horse barns, dog kennels and severe spider infestations. For example, nozzles installed over the horse stalls will mist the synthetic pyrethroids (e.g. permethrin) and the horse’s coat will be treated. The horse may then benefit from hours of repellency when going out to pasture. If horses were treated with natural water based pyrethrins, the product would then biodegrade quickly (e.g. 15 minutes) in the Ultraviolet daylight. County Mosquito Control Districts incorporate many synthetic pyrethroids in their public mosquito control fogging programs. In most residential applications, natural pyrethrins are sufficient for controlling insects, so it is not necessary to use synthetic pyrethroids.