Sorry, layman here, but in what sense is a substance with a name like that "organic"? It neither sounds natural nor does it contain carbon to be called organic in the chemistry sense...
This is "organic" in the sense of "approved for use in organic agriculture." Which generally means "no icky multinational chemical firms that [average lay person] is aware of had a hand in the manufacture of it."
(anecdotal:) Most people all over the world think 'organic' when it's not about organic chemistry or a list of 'approved' things or a label some agency sticks on things that are considered 'organic'. Organic in the sense of organic pesticides are the kinds of pesticides that you'd find in the wild, without them being man-made. That doesn't exclude synthetic replication, because if you can mass-produce that thing that was already there anyway, that's a good way making it available for more uses. That said, some 'organic pesticides' may be introducing an insect that is a predator to the insect you are trying to get rid of. While a 'pest' in 'pesticide' doesn't mean just insects, you usually have organic predators that don't harm your produce while hunting the pest that does attack it.
Say you have a fungus that eats at your corn, maybe there is another one that just eats that fungus but leaves the corn alone. Or maybe you have some insect that eats your wheat, and some naturally occurring compound exists that is bad for the exoskeleton of that insect; put compound (found naturally or replicated synthetically) on the wheat, insects will be sad/dead/gone, there ya go, organic pesticide.
Those natural, or, organic pesticides usually evolved with some specific target in mind, while man-made pesticides are more like chemo therapy: kill as much as possible without killing the produce we want. This has the downside that killing as much as possible actually kills things we don't want killed.
Organic is something that is not synthetic (the intricate philosophical details being left as an exercise).
Obviously, and sarcasm apart, the difference is nuanced. Organic Farming revolves around what is apparently natural, and in practice there is just a list farmers must respect.
I've been paraphrasing myself a lot these days, only to avoid saying the same thing many times. But in my humble opinion as a farmer, Organic Farming is a secular kosher for urban people. It has nothing to do with better farming practices, and everything to do with a sense of control over purity - purity in terms of what is closer to the urban conception of what constitutes True Nature.
Better farming practices involves the rational use of pesticides, synthetic or otherwise, used only as a last resort and having always in mind the effects to Nature (soil, water and wildlife) and human beings (farmers and consumers). In Europe all of these considerations are contemplated under an official standard called Integrated Farming - Organic Farming's big sister, as I call it.
