Many insects chew on plants, and leave small (or large) holes in the leaves.  This damage is separate from yellowing and wilting of leaves, as seen especially in your last image.  The picture is not clear, but appears to me to be some sort of grasshopper.  My best advice in a herb garden where insecticide use is not desired is hand removal and/or use of fabric barriers (row covers) if hand removal is insufficient. You will not find many organic insecticides that are highly effective on large chewing insects like grasshoppers. Neem extract or neem oil is effective on some grasshopper species, and might be worth a try. Don't expect fast control of the hoppers, but it should make the plants a little less attractive for feeding.  Finally, organic gardeners must learn to put up with a certain level of leaf damage.  Most plants can put up with it as well, easily tolerating loss of 20-40% of leaf area without stunting or hurting the plant. Don't expect a perfect looking garden when going natural.