Interesting article on organic pesticides and how many of them may be just as lethal, if not more so, than synthetic ones! A pesticide is a pesticide, and is designed to kill. How carefully a pesticide is used is often more important than what pesticide is used! – 
The label ‘natural’ is presumed to speak for itself. Since ‘natural’ does not equal ‘harmless’, some scepticism is called for. Basically many plants are toxic – an adaptation to avoid being eaten. A ramification of this is that some plants are not particularly good for one’s well-being.

But there is some justification for fearing some of the synthetic pesticides. These chemicals are formulated purposely to be poisons. Furthermore, they are often applied in vast quantities. This adds up to a lot of poison. In some cases the toxicity of these pesticides, to non-target species, has been known since the 1950s. An example could be the near obliteration of Salmon in the Miramichi River, in New Brunswick. This salmon die-off was the inadvertent result of DDT spraying to control spruce budworms. And it has likewise been known since the 1950s that over-use of pesticides can result in the elimination of natural pest controls. A classic example, from Nova Scotia in the 1950s, was the spraying of apple orchards with DDT for codling moth control. This resulted in a resurge in parasitic mites. The DDT killed off the insects that preyed on these mites. As a result the mite populations exploded, and the apple harvests were no better than before (Carson 2002). On the other hand, farming without any pest control is just not workable. Since there must be some pest control, it is incumbent upon agricultural science to find more balanced methods of controlling pests.

Rotenone is extracted from Lonchocarpus spp. roots, it can also be derived from Derris spp..
Advantages: Rotenone is an effective killer of aphids, thrips, caterpillars, sawflies, beetles and mites. (It is especially effective on leaf eating insects.) Rotenone breaks down rapidly, within days.
Disadvantages: Rotenone is more acutely toxic than many synthetic pesticides. Chronic exposure to rotenone has been tentatively linked to Parkinson’s disease in humans. It is fairly toxic to mammals and birds. It is very toxic to fish. (It has been used for centuries to stun fish.) It is not quick acting and may take several days to actually kill insects and mites, after they ingest it.
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