 Naturally derived insecticides allowed for use on organic farms use include "Bacillus thuringiensis" (a bacterial toxin), pyrethrum (a chrysanthemum extract), spinosad (a bacterial metabolite), neem (a tree extract) and rotenone (a legume root extract).Fewer than 10% of organic farmers use these pesticides regularly; one survey found that only 5.3% of vegetable growers in California use rotenone while 1.7% use pyrethrum.These pesticides are not always more safe or environmentally friendly than synthetic pesticides and can cause harm.