If you are not squeamish about bugs and have a small vegetable garden, you can get by hand-removing unwanted pest on your plants. I don't use pesticides in my garden because it will also kill off helpful predator insects like the ladybug.
During the course of the summer, ladybugs will show up depending on whether there is a food source. When there isn't they move on. I have also had some success with a mixture of 1/3 vinegar to 2/3 water and have used this to spray on aphids.
Once a day I inspect my garden. The only real troublesome insect so far has been the asparagus beetles that appear in May. The female beetles lay eggs all over the plant that hatches into larva that feeds on the plant itself. They feed for about two weeks and then fall to the ground to pupate in the soil. About a week later, adults emerge to start another generation, feeding on the ferns for the remainder of the growing season.
I received some unexpected help this summer from the orioles in my yard who discovered the asparagus larva. I wish I could have gotten a photo of this, but I often see the most interesting things when my camera is somewhere else.