Summer is Here and so are the Aphids
Niki Kenniff
Agriculture & Horticulture Program Assistant
It’s finally summer! The plants are looking great, but then you see….little specks on your plants.
A common insect pest seen on a wide variety of ornamental and food crops is aphids. Aphids are small (about 1/8 of an inch long), pear-shaped, and come in many colors such as green, black, gray, yellow, or red. Aphids have a unique pair of small, tube-shaped protrusions that look like tiny pipes on the back side of their bodies called cornicles. The presence of cornicles is an easy way to identify aphids. They feed by sucking sap from buds, leaves, twigs, and developing fruit. This feeding can cause leaves and fruit to be distorted or misshapen. As they feed, much of the sap is passed through their system and excreted as honeydew, a sweet and sticky substance that can adhere to any surface it falls on, such as cars or roofs. Honeydew can lead to the development of sooty mold fungus on your plants. Aphids can also carry several plant viruses and can therefore become a vector as they pass the virus on to the plant during feeding.
If you are unable to clearly see the insects on the plants, grab a magnifying glass or use your phone to take a picture and then zoom in. It is important to correctly ID insect pests for proper treatment. Any local K-State Research and Extension Office should be able to help identify insects found inside or outside the home. Bring a few of the insects in a sealed bag with relevant information about the location/plant type and where the insects were found.
Aphids have a few natural enemies that can help control the pest population. Insects that feed on aphids include syrphid fly larvae, green lacewing larvae-also called aphid lions, lady beetles (and their larvae), and very small wasps called braconids. It may take a bit of time for these natural predators to arrive, but they can be very effective. A single aphid lion can consume 600 aphids over a two to three-week period.
Aphids are not typically a real danger to the survival of your plants, although they can cause aesthetic damage. Aphids are usually controlled effectively by nature. Adverse weather conditions such as heavy rains and low temperatures, as well as fungus diseases, insect predators, and parasites, keep the aphids in check. Simply spraying the impacted plants with a strong stream of water from a hose can be enough to dislodge them from the plant. Manually removing them from the plants is also effective.
Insecticide applications kill beneficial insects as well as pests and can leave your plants unprotected if pest resurgence occurs. Since beneficial insects play an important role in natural aphid control, waiting for natural enemies to control the issue can be a better long-term solution. If chemical measures are needed, try insecticidal soap, horticultural oil or permethrin. Keep in mind that eradicating all insect pests is not realistic. Insects are an important part of the natural balance. Happy Gardening!