Insect Problems

Aphids

Aphids usually prefer the newer growth on plants. They often blend in with the color of the plant although they can be found in almost any color from reds to greens.

Natural predators, such as the parasitic wasp shown on the right with the aphid, help keep aphid numbers under control.

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Aphid and Parasitic Wasp

Aphids, though small, are large enough to be seen with the naked eye. In the early stages of infestation, seeing a few aphids is about the only indicator available. A few aphids can be seen on the dogwood leaves at the right.

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As the infestation increases, the new growth leaves of the plant begin to curl, as shown on the right.

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Aphids feed on plant fluids and then excrete a liquid waste. This leads to a third indication for the presence of aphids. The waste is known as "honey dew" and forms a wet, sticky, glistening film on foliage.

Picture of Honey Dew on Leaf.

Aphids Continued

A strong stream of water from a hose will dislodge aphids. If the stream of water is too strong the plant will be damaged. In the case of large plants, aphids tend to be removed from one location to another location on the same plant.

Picture of hose being used to wash aphids off dahlia plant.

Insecticidal soap and many chemical insecticides provide very good control of aphids.

Picture of a variety of chemical insecticides that effectively control aphids on dahlias. In all cases, the instructions on the label should be followed.

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