Artificial pesticides is the naturalistic fallacy rearing its ugly head.

Some of the pesticides which are allowed in organic farming are quite pernicious. It stands to reason that the opposite is true, and some of the pesticides used by conventional farming are less of an insult to ecosystems and human health than the 'natural' ones.

Banning 'artificial' pesticides, in other words, is a blunt instrument, one which stands a good chance of not accomplishing the actual goal toward which the legislation is intended.