As I have discussed many times on this blog, organic farming is an ideological approach to farming that is ultimately harmful to the environment and agriculture. This is because it is not evidence-based, but rather is based on a dubious philosophy, the notion that methods that are more “natural” (a poorly defined concept) are inherently safer and superior to methods that are “artificial”. The term “organic” is mainly used as a marketing term to create a health halo around products that allow for charging an ideological premium, without any proven benefit.

One aspect of organic farming is that it does not allow for the use of synthetic pesticides, but does allow for the use of natural pesticides. Conceptually this makes no scientific sense – substances which occur in nature can be deadly poisons, just as synthetic substances can. The degree to which something is “natural” is completely orthogonal to how safe or toxic it is to various domains of life. Using natural as a proxy for safety is therefore a completely unscientific and nonsensical approach, but that is organic farming.

Pest management is one of the greatest challenges of modern agriculture. The problem comes from the fact that we are packing in rows and rows of the same crop. That presents an attractive food source to anything that can eat it. Pests can be devastating to crops, and so keeping them under control is necessary for successful agriculture. There are a number of methods that can be used, and experts generally recommend what is called integrated pest management (IPM), which uses multiple methods to reduce pest burden on crops. IPM includes the judicious use of pesticides where necessary, and both conventional and organic farming uses pesticides with organic farming limiting itself to those it deems “natural”.

As an aside, there is a remarkable overlap between the marketing of organic farming and alternative medicine, and they both use similar strategies. One strategy is to put conventional practice in a box, falsely claiming it is limited to a narrow set of approaches which can then be demonized. Alternative medicine propaganda, for example, falsely claims that standard medicine is limited to drugs and surgery. It then attempts to take credit for a long list of standard treatments, such as physical therapy, dietary changes, exercise, etc. that it simply rebrands as alternative. Organic farming plays a similar game, trying to take credit for any practice that is sustainable or does not use synthetic chemicals. In fact proponents present organic farming as sustainable farming, as if they are the same, but they are not. Organic farming is pseudoscience. Sustainable farming is an approach to agriculture that freely uses any techniques which are based in evidence and lead to the most sustainable outcomes (whether they qualify as organic or not).

Getting back to IPM – while it is true that organic farmers tend to use less pesticide overall than non-organic farming, they still do use pesticides, as long as they are natural and not synthetic. They then pretend that pesticides are solely a tradeoff of standard agriculture, and many people falsely believe that organic farming uses no pesticides. Further they assume that their pesticides are safe because they are natural, but this is an unwarranted assumption. Their philosophy, in fact, leads them to not properly test the full effects of the pesticides they use. They literally replace evidence with belief.

In fact, often when scientists study the effects of organic pesticides the results are not good. Some organic pesticides are more toxic than synthetic alternatives. Further, organic pesticides tend to be less effective, require more and more frequent applications, with greater negative effects on the environment.

A recent study adds more evidence to the conclusion that we cannot assume organic pesticides are safe. Researchers looked at a popular organic insecticide called spinosad. Up until now the mechanism and safety of this substance was not known.  They found:

Chronic exposure of adult virgin females to low doses of spinosad leads to mitochondrial defects, severe neurodegeneration, and blindness. These deleterious effects of low-dose exposures warrant rigorous investigation of its impacts on beneficial insects.

They studied the vinegar fly Drosophila because it is physiologically similar to many beneficial insect species, so there is good reason to suspect collateral harm to beneficial insects from its use. Further, they studied exposure doses that are similar to what we would expect from incidental exposure from usual use of the insecticide. This study shatters any assumption of safety for this pesticide, and is more evidence that using the “natural” proxy is essentially worthless.

Spinosad should be further studied, and in fact its use should probably be suspended until such research is complete, given that there are alternatives which are almost certainly safer. It’s easy to point the finger at conventional agriculture, which the organic lobby does frequently, stoking fears of pesticides while hiding behind the fact that the pesticides you are using have simply not been studied.