Aphids (Aphis spp.)
Detailing the identifying qualities of the Aphids, including physical features and territorial reach.
Updated: 1/31/2018; Authored By Staff Writer; Content ©www.InsectIdentification.org
Aphids may seem too small to bother with, but many of these small insects can together become a mighty destructive plant foe.
Tiny and varied in color, these insects suck the juice of plants to the point where the plants, wilt, dehydrate, and possibly die. They also spread viruses that can kill plants. They are a popular nemesis to gardeners and farmers when they form large colonies on vegetation. Some species of lady beetles, moth larvae, and wasps eat them, however, some aphids are toxic giving them an advantage against predators. Most female aphids are wingless, but winged ones will return to their original plant after starting populations elsewhere. They can be mechanically removes (killed by hand), but small size and quick escape make it a inefficient means of removing them.
Aphids come in a variety of species. Colors vary by species, but popular ones are either green, yellow, or white. A group called "woolly aphids" are covered in a white, waxy substance that resembles cotton or fuzz. All types of aphids pierce the plant at its leaves and stems. They digest plant juices and excrete a sticky, sugary 'honeydew' liquid which may attract other garden insects. Ants have been seen shepherding aphids and harvesting their sweet honeydew for consumption for themselves and their ant colonies. The honeydew can also turn black with mold and look like a layer of dark ash, or soot, on the leaves and stems, ruining the beauty of an ornamental plant.
Small populations of Aphids are generally not a major problem for gardeners, however, they are really fast at reproducing. Large populations can take over a crop if not controlled. Many gardeners buy containers of live lady beetles (ladybugs) to spread over their garden in an attempt to curb population growth of aphids; success is varied as a lady beetle may leave the release area before making an impact on the Aphid population. Recognizing and allowing fire beetles and parasitic wasps to visit the infested plants can also aid in reducing aphid numbers naturally and curb plant damage. Chemical pesticides that specifically kill aphids also exist, but usually require multiple applications because they may only be effective at certain life stages and colonies often consist of different developmental ages.