A very common garden and landscape pest, aphids are small, soft-bodied insects less than 1/8” in length.  While a majority of aphids are green or black in color, a variety of other colors have also been noted.  All aphids have cornicles (tubes) at the rear end of their bodies, whose function is to secrete substances which aid in protecting the aphid from predators.  Aphids cause injury to plants during feeding in which they suck sap and other juices from the plant in areas of new growth.  This process damages the plant’s ability to process its own food and commonly causes the plant to wilt, distort or become spotted.  Aphids also transmit viral disease from unhealthy plants to healthy ones during feeding.  Living in large colonies, aphids are found together with ants in a symbiotic relationship.  Ants feed on the honeydew produced by the aphids and provide them with protection.  Ants have even been known to store aphid eggs in their own nests over winter.  In the spring, the ants transport the aphids back to host plants and resume their protection.  Excess honeydew produced by thriving colonies may drip from infested trees and plants.  The substance is very sticky and tends to create quite a mess on cars, porches, sidewalks and anywhere else it lands.  Aphids are a common problem in areas that protect them from their natural predators including inside greenhouses.  Biological control is available in the form of lady beetles and lacewings which are commercially available.  Controlling ant populations will increase the success of biological control in this method as it decreases the aphids’ protective army.  Insecticidal control methods are also available, but caution should be used and labels should be read carefully.  These applications are often not available for consumable foods or may require set periods of time to pass before consumption is allowed.