Answer: Pyrethrum and related products like pyrethrins are toxic to fleas. They are sold under various brand names. Beneficial nematodes have also been shown to be effective outdoors against the larvae of fleas which are developing in the turf or at the soil surface.
Insect growth regulators, although not organic, are very popular and effective. Two examples are the products Archer and FleaFix. They do not kill fleas, but rather prevent the development of fleas from eggs to adults, thereby shutting down the flea outbreak. They are used at very low rates so people wishing to reduce pesticide use often prefer them. Make sure and select one labeled for outdoor use.
If you have indoor pets, in order to win the war on fleas you must simultaneously treat the pet and the outdoor and indoor areas. Effective flea control is based on stopping adults as well as developing eggs, larvae and pupae. This will take more than one treatment in most cases. Otherwise in a few weeks you are back where you started.
The following company's web site has a lot of additional information on effective flea control without synthetic sprays. They also offer an number of low toxicity products including pyrethrin based yard sprays and insect growth regulators for outdoor use:
8708 Grelle Lane, Austin, Texas 78744
To Order: 1-800-658-6699 toll free
Beneficial nematodes and an insect growth regulator for flea control indoors are available from:
5100 Schenley Place
Lawrenceburg, IN 47025
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