Here is a recipe for non-chemical pest sprays for use in your garden. This is not my recipe, though I don't recall where I originally got it.
It will keep for up to a week in your refrigerator, so small batches are best.
1 small peeled onion
2 peeled garlic cloves
1 tsp cayenne pepper
3 cups of water
Place all ingredients in a blender and process until smooth. Let the mix sit overnight in the fridge, then strain the liquid into a spray bottle. Use liberally on plants.