The best policy for treatment of insect problems is to Identify what insect you're dealing with. Then, find out what habitat it thrives in and, once you do that, when ever possible, change the habitat to one they don't like. This will often times make them go away. Sometimes this can mean, planting different plants in that area that the insect(s) aren't attracted to, or changing the soil from wet heavy soil to light sandy soil or vice versa.
If you have bugs that eat wood, find the food source and fix it or get rid of it. Repair and replace any rotted sills or posts around the property. Some areas of the country are now facing problems with wood eating ants or termites that never had them before because of the excessive use of bark mulch in landscaping practices. Use stone mulch or other suitable material if you find this to be the case in your area.
Remember, some insects are beneficial to your landscape and farm. You want them there, like the black ants on your Peonies. They eat the sap that sticks the bud leaves together and make them flower.
You can kill as many bugs as you like but, if the conditions are right for them to be there, they will probably just move back in again and you'll be buying a lot of insecticide with your hard earned money!
Follow the directions on the label of any product you buy and maintain "Good Safety Practice" at all times. Remember, even natural substances can be harmful if used improperly.