Name: Schizaphis graminum

Alias: Greenbugs are one of the fattest members of the aphid family, looking more like a football than a typical teardrop shape as seen in other aphid cousins. It is still rather small, approximately 2 mm in length. They are most often seen as a bright green color (hence the name), but they can also be seen as a yellow, brown or pale green. Most lack wings, leaving them to stumble around slowly. This makes them easy prey for predators. Female greenbugs can reproduce asexually, meaning they can just pop out clones of themselves regularly. This causes their populations to explode quickly.

Crimes: Greenbugs can feed on everything we see valuable, especially grain crops, corn and alfalfa. One small greenbug may not have a dramatic impact on your crop or garden, however in large swarms they can stress crops to the point that yields are severely reduced. They probe their needle-like mouthparts into the phloem of the plant. The phloem has so much pressure they don’t need to expend any energy for it to pass right through them and produce sticky honeydew all over everything.

Redeeming Qualities: None known.

Sentence: Natural predators are the best solution for booming greenbug populations. If you notice ladybugs, lacewings, predatory beetles or evidence of parasitoid wasps in your fields then don’t do anything that will harm their populations. Give them a week or two and they will bring those populations down. If you can’t find natural predators, then chemical action may be warranted. Aphids are susceptible to a wide range of insecticides, and be sure to follow any label instructions

For more information on dangerous and beneficial bugs, call UI Extension educator Joseph Sagers at 208-270-4031 or email